- Research
- Open access
- Published:
Plant Growth-Promoting Rhizobacteria Improve Growth, Morph-Physiological Responses, Water Productivity, and Yield of Rice Plants Under Full and Deficit Drip Irrigation
Rice volume 15, Article number: 16 (2022)
Abstract
Inoculating rice plants by plant growth promoting rhizobacteria (PGPR) may be used as a practical and eco-friendly approach to sustain the growth and yield of drought stressed rice plants. The effect of rice inoculation using plant growth hormones was investigated under drip full irrigation (FI; 100% of evapotranspiration (ETc), and deficit irrigation (DI; 80% of ETc) on growth, physiological responses, yields and water productivities under saline soil (ECe = 6.87 dS m−1) for 2017 and 2018 seasons. Growth (i.e. shoot length and shoot dry weight), leaf photosynthetic pigments (chlorophyll ‘a’ and chlorophyll ‘b’ content), air–canopy temperature (Tc–Ta), membrane stability index (MSI%), and relative water content, (RWC%) chlorophyll fluorescence (Fv/Fm) stomatal conductance (gs), total phenols, peroxidase (PO), polyphenol oxidase (PPO), nitrogen contents and water productivities (grain water productivity; G-WP and straw water productivity; S-WP) were positively affected and significantly (p < 0.05) differed in two seasons in response to the applied PGPR treatments. The highest yields (3.35 and 6.7 t ha−1 for grain and straw yields) as the average for both years were recorded under full irrigation and plants inoculated by PGPR. The results indicated that under water scarcity, application of (I80 + PGPR) treatment was found to be favorable to save 20% of the applied irrigation water, to produce not only the same yields, approximately, but also to save more water as compared to I100%.
Introduction
Rice is a very important cereal crop worldwide, supplying more than 50% of the global food demand. The Global rice production was more than 700 × 106 tons year−1, produced from 167million ha (FAOSTAT 2018). More than 75% of rice production is supplied by irrigated lowland rice (Ram et al. 2003; Yuan et al. 2021). Generally, rice has been grown under flooded conditions with maintaining a continuous water depth of 5–10 cm (Bouman et al. 2007). Lowland rice mainly is direct-seeded or transplanted in puddled soils by plowing under saturated water conditions, and then followed by harrowing and leveling management. Under flooded conditions, a large amount of irrigation water supply is required, which is not only used to cope with water needs for the growth and development of rice plants but also as a management technique during rice cultivation (Brown et al. 1977; McCauley 1990; Sivapalan, 2015). The irrigation water demand for rice plants under the traditional flooded system is more than 20,000 m3 ha−1 which is more than 3–4 times that of its biological needs from water (Tuong et al. 2005; Kruzhilin et al. 2015). In a puddled rice field the consumption of water depends on the rates of evaporation, transpiration, and water losses by percolation, seepage, and surface runoff. Therefore the lower water productivity under irrigated rice conditions is referring to water losses (Abd El-Mageed et al. 2020; Abdou et al. 2021). Soil salinity is abiotic stress that limits both vegetative and reproductive development of grown crops (Abd El-Mageed et al. 2019). Worldwide, more than 800 million hectares of arable land are salt affected (Wang et al. 2011). Plants are induced by salinity that causes ion toxicity, osmotic stress, ion imbalance, mineral deficiencies, physiological and biochemical disruption, consequently, reducing the quality and total yield of the affected crop (Rady et al. 2016).
The availability of irrigation water for agriculture, especially for rice production in many regions of the world, is threatened, not only by the global shortage of water resources (Cai et al. 2020) but also by increasing urban and industrial demand (Boretti and Rosa 2019). Worldwide, the production of rice consumes much water more than that of other crops, it is determined that irrigated rice consumes about 40% of the global water used particularly for irrigation purposes (Bouman et al. 2007; Hoekstra et al. 2011).
In Egypt, after wheat, rice ranked a second staple food and cultivated in reclaimed saline soils, in North delta and coastal areas, rice consumes about 10 billion m3 of water which is about 18% of the Egyptian share of water from the Nile River. Egypt like many countries of the world faces several challenges respecting the increasing water demand and increasing water competition among users, the sustainability of rice production in Egypt is becoming more threatened by the limited water resources (Abd El-Mageed et al. 2020; Abdou et al. 2021). Therefore, the Ministry of Irrigation and Water Resources in Egypt annually reduces the allotted area for rice cultivation, which is decreased by 59% from 745,000 ha to 304,080 ha during the past 10 years (2008–2018).
Water stress negatively affects the growth and productivity of crops (Ahuja et al. 2010; Shekoofa and Sinclair 2018). Physiological functioning in rice plants (Guimarães et al. 2013; Yang et al. 2019; Abdou et al. 2021) viz root length density, root moisture extraction, the rate of apical development, canopy size, leaf elongation rate, leaf rolling, transpiration rate, RWC, biomass production, spikelet number, spikelet sterility, panicle development, grain size, and grain yield (Palanog et al. 2014; Kruzhilin et al. 2016; Yang et al. 2019) may be drastically reduced due to water stress, especially if it occurs during vegetative or reproductive stages of rice, depending upon the stress severity and cultivar tolerance. In recent years, the trickle irrigation system has been spread out more intensely, not only for enhancing water productivity but also for increasing crop production (Geerts and Raes 2009). Drip irrigation can achieve application efficiencies as high as 90% if the system is well maintained and combined with soil moisture monitoring or other ways of assessing crop water requirements (Vickers 2002; Jägermeyr et al. 2015). Water use efficiency and crop production can be enhanced by using drip irrigation under limited water resources by declining the volume of water that leaches out of the root zone (El-Hendawy et al. 2008). Irrigation techniques that tend to minimize the inputs of irrigation water for rice production like deficit irrigation should be applied. Deficit irrigation (DI) is a method mainly applied to decrease water losses and maximize water productivity (WP), particularly in areas where the water supply is inadequate for irrigation (Agami et al. 2018; Abd El-Mageed et al. 2019; Semida et al. 2020). DI can also have other benefits related to reducing the energy used during irrigations and decreasing nitrate leaching (Falagán et al. 2015), reducing production costs and water consumption (Badal et al. 2013; Ballester et al. 2014).
To cope with drought stress, several adaptations and strategies are required. Plant growth-promoting rhizobacteria (PGPR) could play a significant role in the alleviation of induced injurious effects by drought stress on plants (Vurukonda et al. 2016). The role of microorganisms regarding plant growth, nutrient management, and biocontrol activity is very well established. These beneficial microorganisms colonize the rhizosphere/endo-rhizosphere of plants and promote the growth of the plants through various direct and indirect mechanisms (Grover and Ali 2011). Furthermore, the role of microorganisms in the management of biotic and abiotic stresses is gaining importance. The possible explanation for the mechanism of plant drought tolerance induced by rhizobacteria includes (1) production of phytohormones like abscisic acid (ABA), gibberellic acid, cytokinins, and indole-3-acetic acid (IAA); (2) ACC deaminase to reduce the level of ethylene in the roots; (3) induced systemic tolerance by bacterial compounds; (4) bacterial exopolysaccharides (Timmusk et al. 2014; Carlson et al. 2020; Getahun et al. 2020; Poudel et al. 2021). Hence, the application of PGPR may increase water-saving and enhance crop yield productivity under conditions of deficit water supply. Likewise, rice crop responses to combined PGPR with deficit irrigation regimes synchronized with salt affected soils have not yet been investigated. Therefore, the main objective of the current study was to investigate the effect of PGPR application and DI on growth, plant defense system, physio-biochemical attributes, seed and straw yield, and WP of rice plants cultivated in salt soil-affected.
Materials and Methods
Experimental Set-Up
Our study was conducted in the private farm South-east Fayoum, (29° 35′ N; 30° 05′ E) Egypt for two successive years 2017 and 2018. The climate is arid, characterized by low precipitation and rainfall occurs mainly during the period from December to April. The region is also characterized by more than 320 days a year of sunny days. The meteorological parameters (i.e. air temperature °C, relative humidity (%), wind speed (m s−1) and pan evaporation (mm day−1) during the rice cultivation period in 2017 and 2018 were presented in (Table 1). The soil, 80–100 cm deep, is loamy sand and defined as Typic Torripsamments, siliceous, hyperthermic (Soil Survey Staff 1999). Physio-chemical characteristics of the soil were: pH 7.85 (1:2.5 soil/water extract), Kjeldahl total N 1.4 g kg−1, Olsen extractable P 3.53 mg kg−1, ammonium acetate extractable K 42.85 mg kg−1, organic C 8.2 g kg−1, total carbonate 43.7 g kg−1, ECe (soil paste extract) 6.4 dS m−1, bulk density 1.53 kg dm−3, field capacity and wilting point 21.31% and 10.3%, respectively Tables 2 and 3.
Experimental Design and Plant Management
Two field experiments were conducted in a randomized complete block design (Split Plot). 2 irrigation treatments were applied (100, and 80% of ETc were occupied as main plots) and two PGPR treatments (treated and non-treated were allocated to sub-plots). The 4 treatments were replicated three times, making a total of 12 plots. The area of the experimental plot was 16 m length × 0.8 m row width (12.80 m2), each plot included 4 planting rows placed 20 cm apart with a distance of 10 cm between plants within rows. Two drip lines were placed 0.40 m apart in each elementary test plot. Healthy seeds of rice (Oryza sativa L.), variety Sakha 107 were sown on 20 May 2017 and 2018. The 4-week-old transplants were transported and replanted and then harvested on 6 October 2017 and 2018. Mineral fertilization, pest management, disease, and cultural practices were performed as the instructions of local commercial crop production. Irrigation water applied (IWA) was estimated as a percentage of the crop evapotranspiration (ETc) representing the following three treatments: FI = 100%, and DI = 80% of ETc. Daily ETo and ETc were estimated according to Allen et al. (1998) equation.
where IWA: irrigation water applied (m3), A: irrigated plot area (m2), ETc: water consumptive use (mm day−1) and was computed as follow;
ETo is the reference evapotranspiration (mm d−1) and Kc = crop coefficient. ETo was determined as follows:
where Epan is the evaporation from a class A and Kp is the pan coefficient, Ea: efficiency of application (%) and LR: leaching requirements.
Growth and Physiological Measurements
At the tillering stage of both seasons/experiments, 5 individual plants were randomly chosen from each experimental plot to evaluate growth characteristics and another group of 5 plants to determine chemical attributes. Shoot lengths and spikes lengths were measured using a meter scale. The number of spikes was counted per plant, and leaf area per plant was measured using Digital Planimeter (Planix 7). Shoots of plants were weighed to record their fresh weights and then placed in an oven at 70 ± 2 °C till a constant weight to measure their dry weights.
Chlorophyll Fluorescence (Fv/Fm) and Performance Index (PI)
The (Fv/Fm) was measured by using a portable fluorometer (Handy PEA, Hansatech Instruments Ltd, Kings Lynn, UK) and calculated according to Maxwell and Johnson (2000). Where the (PI) of photosynthesis based on equal absorption (PIABS) was calculated as reported by Clark et al. (2000).
Stomatal Conductance (gs) and Leaf Chlorophyll Concentration (SPAD)
The gs was measured on fully expanded upper canopy leaves between 10 and 12 h with a portable photosynthetic system (CIRAS-2, PP Systems, Hitchin, UK). The SPAD was determined at 90 DAS for the three youngest completely expanded leaves per hill by (SPAD-value; SPAD502, KONICAMINOLTA. Inc., Tokyo).
Rice Water Status (RWC %, MSI %, and Canopy Temperature)
The RWC was determined according to Hayat et al. (2007) equation as follows;
where RWC% is relative water content (%), FM: fresh mass (g), TM: turgid mass (g), and DM is the dry mass (g). Likewise, MSI% was determined and calculated using the method of Premachandra et al. (1990) as follow
where MSI % is the membrane stability index, C1: is the EC of the solution at 40 °C and C2: is the EC of the solution at100°C. Canopy temperature (Tc) was measured by a hand-held infrared thermometer (Fluk 574, Everett WA, USA) at an emissivity of 0.98 and a spectral response range of 8–14 µm.
Total Nitrogen and Antioxidant Defense System
Total nitrogen was determined according to the well-known method described by Donald and Robert (1998). Estimations of total phenols, peroxidase (PO), and polyphenol oxidase (PPO) were carried out by the method described by Ramamoorthy et al. (2002).
Chlorophyll ‘a’ and Chlorophyll ‘b’ Content
Chlorophyll ‘a’ and chlorophyll ‘b’ content were extracted and determined (in mg g−1 FW) according to the procedure given by Arnon (1949) using a UV-160 A UV–Vis recording spectrometer (Shimadzu, Kyoto, Japan) at 663 and 645 nm.
Rhizobacteria Strains Preparations and Inoculation of Rice Seedlings
The most effective facultative oligotrophic bacterial two strains used in this experiment as PGPR were isolated from the same soils at Fayoum region, Egypt, and were completely identified as [Bacillus subtilis subsp, spizizenii strain NRRL B-23049T and Bacillus megatherium strain IAM 13418]. The most effective facultative oligotrophic bacterial strains obtained, from the previous part, were selected and chosen for some different characters based on previous knowledge of their ability to produce (indole acetic acid IAA, Salicylic acid, zinc, and phosphate solubilization, N2-fixation, cellulase and chitinase, oxidase, catalase activities and lactose fermentation (Table 4).
For the preparation of bacterial strains inoculants (antagonizers), each strain was grown individually on sterilized nutrient broth medium in flasks with 1 L capacity on rotary shaker after shaking for 72 h incubation period at 30 °C. The growing organisms were concentrated by centrifuging the medium and cell sidements were aseptically collected and diluted, by the same medium, to 250 mL only (1/4 L). In the case of using a mixture of the two antagonizers, an equal volume of the three strains was mixed instantaneously before use. 20 mL of the resultant suspension was poured twice directly onto the rice seedlings in cones at the seedling and at 15 days after transplanting.
Water Productivities
Water productivities as mentioned byFernández et al. (2020) were calculated as (1) the ratio between above-ground biomass and crop evapotranspiration, i.e. straw WP (S-WP) and (2) the ratio between grain yield and crop evapotranspiration, i.e. grain WP (G-WP) according to Jensen (1983).
Statistical Analysis
Statistical analysis was performed through the procedure of GenStat (version 11) (VSN International Ltd, Oxford, UK). The least significant difference (LSD) at 5% probability (p ≤ 0.05) level was used as mean separation test.
Results
Rice Growth in Response to Plant Growth Promoting Bacteria Under Full and Deficit Irrigation
Data in Table 5 illustrate the effects of irrigation level, plant growth promoting bacteria, and their interaction on rice growth. Plants under deficit irrigation had lower growth traits (i.e. shoot length, tillers number plant−1, panicles number plant−1 and shoot dry weight) than those under full irrigation. On the other hand, plants treated with PGPR had higher growth traits (i.e. shoot length, tillers number plant−1, panicles number plant−1 and shoot dry weight) than untreated plants. Growth traits were decreased significantly with increasing water stress, I80% resulted in decreases of plant height by 8%, tillers number by 11.8%, panicles number by 12.4%, and shoot dry weight by 25% as compared to fully irrigated plants. On the other hand, treated rice plants with PGPR increased significantly these parameters by 9.4%, 15.3%, 18.6%, and 29.6% for plant height, tillers number, panicles number, and shoot dry weight, respectively. The combined application of PGPR and irrigation at 100% of ETc recorded the best growth parameters, while the treatment I80 × −PGPR showed the lowest values of growth parameters. Otherwise, no significant differences were found between I100 × −PGPR and I80 × +PGPR treatments.
Rice Water Status
Results of rice water states (RWC, MSI, and canopy-air temperature) in responses to irrigation and PGPR treatments and their interaction are presented in Table 6. The water status of rice plants as evaluated by RWC, MSI, and the canopy-air temperature was significantly affected by irrigation treatment. Data in (Table 6) reflected that RWC and MSI of well-irrigated plants were higher (82.3 and 75.3) than those under deficit irrigation (70.8 and 66.5). On contrary, canopy-air temperature (Tc–Ta) at 13.0 and 14 O’clock of plants irrigated at 100% of ETc (1.24 and 1.59) was lower than plants irrigated at 80% of ETc (1.97 and 2.08). Also, values of RWC, MSI, and the canopy-air temperature were affected positively or negatively by PGPR inoculation. The values of RWC and MSI% for plants treated with PGPR (82.1 and 75.6) were higher than −PGPR plants (63.5 and 73.8). Interaction between PGPR and irrigation treatment significantly affected plant water status. According to the results in Table 6, No significant effects were observed between seasons on RWC, MSI, and Tc–Ta.
Stomatal Conductance (gs)
The influences of plant growth promoting bacteria on stomatal conductance (gs) under full and deficit irrigation are presented in Fig. 1. Results showed that gs values were almost stable from 10 to 11 am but thereafter, gs decreased sharply at 12 pm in all treatments. The values of stomatal conductance were higher under FI than those of DI. Maximum values of stomatal conductance were found in FI + PGPR treatment which was greater than those of FI, DI, and DI + PGPR treatments for all times (10 am, 11 am, and 12 pm). Basically, inoculated rice plants increased gs in comparison to the uninoculated control plant.
Chlorophyll Fluorescence Efficiency, Relative Chlorophyll Content and Photosynthetic Pigments
Responses of chlorophyll fluorescence (Fv/Fm and PI), relative chlorophyll content (SPAD value), and photosynthetic pigments (chlorophyll a and chlorophyll b) of rice plants to irrigation and plant growth promoting bacteria treatments and their interactions are displayed in Table 7. Except for PI, no significant differences were observed between seasons. Chlorophyll fluorescence, relative chlorophyll content, and photosynthetic pigments were significantly influenced by irrigation, PGPR treatments and by their interaction. Results in (Table 7) showed that Fv/Fm, PI, SPAD, chlorophyll "a" and chlorophyll "b" of rice plants under well-watered conditions were compared by water-stressed 7.7, and 14.3%, respectively as compared by water stressed plants. Also, inoculation rice plants by PGPR positively increased Fv/Fm by 5.1%, PI by 66.7%, SPAD by 13.8%, and chlorophyll “a” by 10.5% and chlorophyll “b” by 14.3% as compared with uninoculated plants. Chlorophyll fluorescence, relative chlorophyll content, and photosynthetic pigments were strongly influenced by the interaction between PGPR and irrigation treatments. Maximum values of Fv/Fm, PI, SPAD, chlorophyll a, and chlorophyll b were recorded under I100 × +PGPR treatment, while the minimum values for these parameters were observed under I80 × −PGPR treatment.
Antioxidant Defense System and Nitrogen Contents
The effects of irrigation, PGPR treatments and their interaction on defense principles like [(peroxidase (PO), polyphenol oxidase (PPO) and total phenol)], N% (leaves) and N% (grains) contents of rice plants were presented in Table 8. The concentration of PO, PPO, total phenol and the content of N% (leaves and grains) were strongly (p < 0.05) affected by irrigation quantity and plant growth promoting bacteria and were not positively affected by season except for total phenol. Data in (Table 8) reflected that PO, PPO, total phenol, N content in leaves and grains when rice plants were received 100% of irrigation water requirements were higher by 28.1, 17.7, 7.3, 8.3, and 6.4%, respectively as compared by plants received 80% of ETc. Additionally, rice plants inoculated by PGPR positively increased PO by 20.0%, PPO by 58.3%, total phenol by 24.8%, leaves N content by 33.9%, and grains N content by 20.0% as compared with uninoculated plants. According to the results displayed in Table 8, PO, PPO, total phenol, N content (in leaves, and in grains) were significantly (p < 0.05) affected by the interaction between PGPR and irrigation treatments. The highest values of PO, PPO, total phenol, N content in leaves and grains were found when plants were irrigated at 100% of ETc and inoculated by PGPR treatment (I100 × +PGPR), while the lowest values for the aforementioned parameters were recoded when rice plants were exposed to water stress (I80) and untreated by PGPR (I80 × −PGPR).
Yield Components
Responses of rice yield components such as; panicle length, (cm), panicle weight (g), number of grains panicle−1, and 1000 grain weight (g) to cropping seasons, irrigation, PGPR, and their interaction are presented in Table 9. Rice yield components were positively affected by irrigation level, PGPR, and by their interaction and were not affected by the growing season. Yield components of rice plants exposed to drought stress were decreased by 7.5% for panicle length, by panicle weight 23.7%, the number of grains panicle−1 10.8%, and 1000 grain weight of rice plants by 17.8% as compared with unstressed plants. On the other hand, inoculated rice plants by PGPR increased yield component by 10.6, 28.0, 19.9, and 23.0% for panicle length, panicle weight, number of grains panicle−1, and 1000 grain weight as compared by untreated plants, respectively. Our results showed that rice yield components were strongly influenced by the interaction between PGPR and irrigation treatments. The highest values of panicle length, panicle weight, number of grains panicle−1 and 1000 grain weight (15.8, 2.1, 75.1 and 22.3) were recorded when plants received 100% of ETc and inoculated by PGPR (I100 × +PGPR), while the lowest values for aforementioned traits (13.6, 1.2, 56.2 and 14.7) were recorded when rice plants exposed to water stress (I80) and untreated by PGPR (I80 × −PGPR) treatment.
Rice Yields and Water Productivities
Table 10 illustrates the effects of growing seasons, irrigation level, PGPR, and their interaction on rice yields (grain and straw; t ha−1) and water productivities (G-WP, and S-WP; kg m−3). Plants grown under full irrigation had higher yields (i.e. grain yield, straw yield) than those grown under drought stress. Grains yield, straw yield, were decreased positively with increasing water stress, I80% resulted in decreases of grain yield by 19%, straw yield by 11.9%, in relation to fully irrigated plants. On the other hand, values of G-WP, and S-WP under I80% treatment were higher than those of I100% treatment by 1.3 and 10.4%, respectively, (Table 10). Rice plants treated with PGPR increased grains yield, straw yield, G-WP, and S-WP by 19.0, 16.8, as compared with untreated plants. No significant differences between growing seasons were observed. Our findings showed that grains yield, straw yield, G-WP, and S-WP were significantly affected by the interaction between PGPR and irrigation treatments. Plants fully irrigated and inoculated by +PGPR gained the highest values of grains yield (5.24 t ha−1), straw yield (8.87 t ha−1), G-WP (kg m−3), and S-WP (kg m−3). Moreover, the lowest values for grains yield (3.65 t ha−1), straw yield (6.58 t ha−1), G-WP (kg m−3), and S-WP (kg m−3) were found when rice plants were irrigated at 80% of irrigation water requirements (I80) and untreated by PGPR.
Discussion
Water scarcity is one of the main constraints to agricultural production worldwide, and it is expected to intensify in the future. In arid soil where irrigation is necessary for the production of crops, producers are seeking techniques to save water by increasing the efficiency of irrigation water. Plant growth promoting rhizobacteria (PGPR) is considered one of these strategies and it could play an important role in mitigating the detrimental effects of drought stress on plants. Bacteria strains used in our study [Bacillus subtilis subsp. and Bacillus megatherium] can produce plant growth promoting substances (PGPs) such as; Indoleacetic acid (IAA) (Loper and Schroth 1986), salicylic acid (Meyer and Abdallah 1978), siderophores (Palli 2005), chitinase (Renwick et al. 1991), cellulose (Andro et al. 1984), phosphate and Zinc solubilization (Rodriguez and Miller 2000; Saravanan et al. 2004) and N2-fixation (Cattelan et al. 1999). Besides, it has antagonistic activity against pathogenic fungi like; Pythium ultimum, Rhizoctonia solani, and Fusarium sp (Koch 1997). The strains also have the capability to live, proliferate sustain life and perform their activities under some adverse environmental conditions such as; temperature, increasing pH, and salt stress. Therefore, Bacillus subtilis subsp. and Bacillus megatherium are considered as plant growth promoting rhizobacteria (PGPR) and it could use under normal conditions and overcome the negative effects of environmental stresses on some plants (Abdelaziz et al. 2018). The current study has used PGPR as soil application for deficit irrigation DI-stressed rice plants grown under salt stress (ECe = 6.3 dS m−1). Inoculating plants with PGPR showed greatly significant positive results for performance growth, water status, stomatal conductance (gs), and chlorophyll fluorescence efficiency, relative chlorophyll content and photosynthetic pigments, antioxidant enzymes and nitrogen contents, yield component, and yields and water productivities of rice plants grown under both DI and saline conditions. In our study, drought stress indirectly inhibited rice growth parameters may be attributed to the drought-induced reduction of cell division and enlargement, resulting in the reduction of shoot length, tillers number plant−1, the number of panicles plant−1 and shoot dry weight, simultaneously with the reduction of stomatal conductance, water status, chlorophyll fluorescence efficiency, relative chlorophyll content and photosynthetic pigments, as well as antioxidant enzymes and nitrogen contents (Selvakumar and Panneerselvam 2012; Steduto et al. 2012; Abd El-Mageed et al. 2021). On the other hand, inoculation water-stressed rice pants (80% ETc) with PGPR alleviated the deleterious effects of water shortage on rice growth, showing that increased shoot length, tillers number plant−1, number of panicles plant−1 and shoot dry weight similar to those produced in fully irrigated plants inoculated with PGPR. Also, compared to the untreated plants, inoculation by plant growth promoting bacteria improved rice growth. Rice growth-promoting because of adding PGPR may be linked to the increased micronutrient uptake and affect phytohormones homeostasis. The inoculation effect of our bacterial isolates had a remarkable positive effect on plant growth parameters under stress and non-stress condition. Various studies indicated that PGPRs inoculated plants can take up a higher volume of water and nutrients from rhizosphere soil; the attributes could be useful for the growth of plants under drought stress (Alami et al. 2000). The enhancement of rice growth traits treated with PGPR under water stress may be due to phytohormones like abscisic acid (ABA), indole-3-acetic acid (IAA), salicylic acid, gibberellic acid, cytokinins, and exopolysaccharides which produced by PGPR and help plants to cope with drought stress. A similar trend was reported by Yang et al. (2009), Kim et al. (2012) and Timmusk et al. (2014). The study displayed that rice plants irrigated at 80% ETc and untreated with PGPR produced not only reduction of rice water status (MSI and RWC) but also decreased chlorophyll fluorescence (Fv/Fm and PI) SPAD value, chlorophyll ‘a’ and chlorophyll ‘b’ as well as stomatal conductance, indicating the negative effects of water stress on rice. On the other hand, the canopy-air temperature of rice plants increased by 0.61 °C (Tc–Ta) under water stress (I80%) compared to full irrigation. Our results showed that inoculating rice plants with Bacillus subtilis subsp. and Bacillus megatherium as a plant growth promoting rhizobacteria (PGPR) stabilized membrane integrity and maintained cell turgor of rice leaves under drought stress. In this concern, increases of tissue RWC and MSI chlorophyll fluorescence (Fv/Fm and PI) SPAD value, chlorophyll ‘a’ and chlorophyll ‘b’ and decreases of canopy temperature (Tc–Ta) as metabolically available water, enabling to maintain tissue health and reflect on the metabolic processes in rice under drought stress. Our results are in line with those reported by Creus et al. (2004), Arzanesh et al. (2011), Liu et al. (2013) and Armada et al. (2014), who reported that PGPR helped plants by increasing leaf water content which was ascribed to the production of plant hormones such as IAA, by the bacteria that improved root growth and formation of lateral roots their by increasing uptake of water, decreased leaf transpiration, improved nutrition and physiology, controlling stomatal closure, and metabolic activities. Also, it was documented that under water stress chlorophyll content (Chl a, and Chl b or SPAD), stomatal conductance, chlorophyll fluorescence (Fv/Fm and PI), photosynthetic parameters as well as water state were increased when plants treated PGPR compared to untreated plants (Wang et al. 2012; Elekhtyar 2015; Samaniego-Gámez et al. 2016; Zhang et al. 2019). In the present work the reduction of antioxidant defense system (e.g., peroxidase (PO), polyphenol oxidase (PPO), total phenol), N% (leaves), and N% (grains) under drought stress may be due to the influences of drought stress on the availability and transport of nutrients, as soil nutrients are carried to the roots by water. Our results are in line with those of Selvakumar and Panneerselvam (2012), Abd El-Mageed et al. (2017) and Semida et al. (2021a). They reported that water stress reduces nutrient diffusion and mass flow of water-soluble elements such as nitrate, K, Ca, Mg, and Si. Moreover, drought induces free radicals affecting antioxidant defenses such as superoxide radicals, hydrogen peroxide, and hydroxyl radicals. However, our study exhibited that the negative effects on antioxidant defense system (e.i., peroxidase (PO), polyphenol oxidase (PPO), and total phenol), N% (leaves), and N% (grains) of water-stressed rice were alleviated by inoculated by PGPR, thereby enhanced antioxidant enzymes and N% contents (leaves and grains). In these concerns, Yogendra et al. (2015) reported that PGPR mitigates oxidative damage in rice plants grown under drought by increasing plant growth and activating antioxidant defense systems, thereby enhancing the stability of membranes in plant cells. Additionally, PGPR increased rice biomass production grown under drought stress. Enhancement of the plant dry biomass is a positive criterion for drought tolerance correlates with an increase of rice yields (Yogendra et al. 2015). Our strains have the ability to fix N, thus led to an increase in N uptake in leaves and grains These positive results in response to PGPR application may be related to PGPR and regulated the redistribution and uptake of N, besides restoration of photosynthetic efficiency (Rodriguez et al. 2004; Anjum et al. 2007), and more metabolites required for rice growth. Drought stress (I80%) positively decreased rice yield attributes (e.g., panicle length, panicle length, panicle weight, grains number panicle−1, and 1000 grain weight) and yields (grain and straw) compared to fully irrigated plants (I100%). The reduction in yield components under water stress may be due to the decreases in growth, stomatal conductance, chlorophyll content, water status, N uptake, and photosynthesis efficiency of plants (Quampah et al. 2011; Pejic et al. 2011). Consequentially, the reduction in panicle length, panicle length, panicle weight, grains number panicle−1, and 1000 grain weight decreased the yield of grain and straw. In these concern, Pantuwan et al. (2002), Wu et al. (2011), Kumar et al. (2014) and Yang et al. (2019) reported that water stress could cause spikelet degenerate, spikelet sterility, and grains number reduce unfilled grain No. increase, and 1000-grain weight and yield reduce. The G-WP values were not affected significantly by the irrigation quantity where S-WP values were significantly affected and the highest values for G-WP and S-WP were recorded under I80% treatment. A similar trend was reported by Semida et al. (2014) and Rady et al. (2021a, b). In general, according to the results of various experiments, lower water application provides higher WP values (Rady et al. 2021a; Semida et al. 2021b). Li et al. (2001) indicated that limited irrigation in wheat during the growing season could significantly increase WP. Abd El-Mageed et al. (2018) and Agami et al. (2018) found that the highest values of WUE for sorghum and wheat were recorded via low moisture conditions (60% of Class A pan evaporation). Results of the current study indicate that inoculation rice plants by PGPR enhanced yield, yield components, and G-WP and S-WP irrespective of irrigation treatment, and the higher rice values were noted when rice plants irrigated well and inoculated by bacillus subtilis, and bacillus megatherium strains. This could be as a result of enhancing the survival, and growth yield, yield components, and G-WP and S-WP under PGPR inoculation by improving morpho-physiological responses, chlorophyll efficiency, plant water status, providing higher protection for plant tissues and thus led to an increase in yields and water productivities. This result is found to be in harmony with Hussain et al. (2014) for wheat, Kang et al. (2014) for soybean, Cohen et al. (2009) for maize, Cassán et al. (2009) and García de Salamone et al. (2012) for rice. They concluded that the application of PGPRs in plants increased yield and alleviated water stress by various mechanisms such as; reduced oxidative damage, increased proline, abscisic acid, auxin, gibberellin, and cytokinin content; improved vegetative growth, water status of the plant, photosynthetic capacity and nutrients status; enhanced physiological and biochemical attributes.
Conclusion
Exposure of rice plants to drought stress positively reduced, physiological responses, RWC%, MSI%, antioxidant enzymes (e.i., peroxidase (PO), polyphenol oxidase (PPO), total phenol), N% (in leaves and grains), growth attributes, grain, and straw yields and increased canopy temperature the of rice plants. However, inoculation rice plants with PGPR could mitigate the deleterious effects of water stress by enhancing leaf photosynthetic pigments, chlorophyll fluorescence, SPAD value, stomatal conductance, plant water status, antioxidant enzymes, plant growth, yields, and WP and reduce plant canopy temperature. Depending on the obtained results it could be summarized that the treatment (I100 × +PGPR) is the most suitable for obtaining the highest grain and straw yields. Under water deficit, the application of (I80 × +PGPR) treatment was found to be a favorable strategy to save 20% of the applied irrigation water, providing the same rice yield. Our results suggest that PGPR applications may find value as anti-abiotic stresses for improving rice growth and productivity under drought stress.
Availability of Data and Materials
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.
References
Abd El-Mageed TA, Semida WM, Rady MM (2017) Moringa leaf extract as biostimulant improves water use efficiency, physio-biochemical attributes of squash plants under deficit irrigation. Agric Water Manag 193:46–54. https://doi.org/10.1016/j.agwat.2017.08.004
Abd El-Mageed TA, Samnoudi IME, Ibrahim AEM, El Tawwab ARA (2018) Compost and mulching modulates morphological, physiological responses and water use e ffi ciency in sorghum (bicolor L. Moench) under low moisture regime. Agric Water Manag 208:431–439. https://doi.org/10.1016/j.agwat.2018.06.042
Abd El-Mageed TA, El-sherif AMA, Abd El-Mageed SA, Abdou NM (2019) A novel compost alleviate drought stress for sugar beet production grown in Cd-contaminated saline soil. Agric Water Manag 226:105831. https://doi.org/10.1016/j.agwat.2019.105831
Abd El-Mageed TA, Abdurrahman HA, Abd El-Mageed SA (2020) Residual acidified biochar modulates growth, physiological responses, and water relations of maize (Zea mays) under heavy metal-contaminated irrigation water. Environ Sci Pollut Res 27:22956–22966
Abd El-Mageed TA, Shaaban A, Abd El-Mageed SA et al (2021) Silicon defensive role in maize (Zea mays L.) against drought stress and metals-contaminated irrigation water. SILICON 13:2165–2176
Abdelaziz S, Hemeda NF, Belal EE, Elshahawy R (2018) Efficacy of facultative oligotrophic bacterial strains as plant growth-promoting rhizobacteria (PGPR) and their potency against two pathogenic fungi causing damping-off diseases. Appl Microbiol Open Access. https://doi.org/10.4172/2471-9315.1000153
Abdou NM, Abdel-Razek MA, Abd El-Mageed SA, Semida WM, Leilah AAA, Abd El-Mageed TA, Ali EF, Majrashi A, Rady MOA (2021) High nitrogen fertilization modulates morpho-physiological responses, yield, and water productivity of lowland rice under deficit irrigation. Agronomy 11:1291. https://doi.org/10.3390/agronomy11071291
Agami RA, Alamri SAM, Abd El-Mageed TA et al (2018) Role of exogenous nitrogen supply in alleviating the deficit irrigation stress in wheat plants. Agric Water Manag 210:261–270
Ahuja I, de Vos RCH, Bones AM, Hall RD (2010) Plant molecular stress responses face climate change. Trends Plant Sci 15:664–674. https://doi.org/10.1016/j.tplants.2010.08.002
Alami Y, Achouak W, Marol C, Heulin T (2000) Rhizosphere soil aggregation and plant growth promotion of sunflowers by an exopolysaccharide-producing Rhizobium sp. strain isolated from sunflower roots. Appl Environ Microbiol 66:3393–3398. https://doi.org/10.1128/AEM.66.8.3393-3398.2000
Allen RG, Pereira LS, Raes D, Smith M (1998) Crop evapotranspiration: guidelines for computing crop requirements. Irrigation and drainage paper no. 56. FAO irrigation and drainage paper no. 56, Rome, Italy
Andro T, Chambost JP, Kotoujansky A et al (1984) Mutants of Erwinia chrysanthemi defective in secretion of pectinase and cellulase. J Bacteriol 160:1199–1203. https://doi.org/10.1128/jb.160.3.1199-1203.1984
Anjum M, Sajjad M, Akhtar N et al (2007) Response of cotton to plant growth promoting rhizobacteria (PGPR) inoculation under different levels of nitrogen. J Agric Res 45:135–143
Armada E, Roldán A, Azcon R (2014) Differential activity of autochthonous bacteria in controlling drought stress in native lavandula and salvia plants species under drought conditions in natural arid soil. Microb Ecol 67:410–420. https://doi.org/10.1007/s00248-013-0326-9
Arnon DI (1949) Copper enzymes in isolated chloroplasts. Polyphenol-oxidase in Beta vulgaris L. Plant Physiol 24:1–5
Arzanesh MH, Alikhani HA, Khavazi K et al (2011) Wheat (Triticum aestivum L.) growth enhancement by Azospirillum sp. under drought stress. World J Microbiol Biotechnol 27:197–205. https://doi.org/10.1007/s11274-010-0444-1
Badal E, El-Mageed TAA, Buesa I et al (2013) Moderate plant water stress reduces fruit drop of “Rojo Brillante” persimmon (Diospyros kaki) in a Mediterranean climate. Agric Water Manag 119:154–160. https://doi.org/10.1016/j.agwat.2012.12.020
Ballester C, Castel J, Abd El-Mageed TA et al (2014) Long-term response of “Clementina de Nules” citrus trees to summer regulated deficit irrigation. Agric Water Manag. https://doi.org/10.1016/j.agwat.2014.03.003
Boretti A, Rosa L (2019) Reassessing the projections of the World Water Development Report. NPJ Clean Water 2:15. https://doi.org/10.1038/s41545-019-0039-9
Bouman B, Lampayan R, Tuong T (2007) Water management in irrigated rice; coping with water scarcity. International Rice Research Institute
Brown KW, Turner FT, Thomas JC et al (1977) Water balance of flooded rice paddies. Agric Water Manag 1:277–291. https://doi.org/10.1016/0378-3774(77)90006-3
Cai J, He Y, Xie R, Liu Y (2020) A footprint-based water security assessment: an analysis of Hunan province in China. J Clean Prod. https://doi.org/10.1016/j.jclepro.2019.118485
Carlson R, Tugizimana F, Steenkamp PA, Dubery IA, Hassen AI, Labuschagne N (2020) Rhizobacteria-induced systemic tolerance against drought stress in Sorghum bicolor (L.) Moench. Microbiol Res 232:126388. https://doi.org/10.1016/j.micres.2019.126388
Cassán F, Maiale S, Masciarelli O et al (2009) Cadaverine production by Azospirillum brasilense and its possible role in plant growth promotion and osmotic stress mitigation. Eur J Soil Biol 45:12–19. https://doi.org/10.1016/j.ejsobi.2008.08.003
Cattelan AJ, Hartel PG, Fuhrmann JJ (1999) Screening for plant growth-promoting rhizobacteria to promote early soybean growth. Soil Sci Soc Am J 63:1670–1680. https://doi.org/10.2136/sssaj1999.6361670x
Clark AJ, Landolt W, Bucher JB, Strasser RJ (2000) Beech (Fagus sylvatica) response to ozone exposure assessed with a chlorophyll a fluorescence performance index. Environ Pollut 109:501–507. https://doi.org/10.1016/S0269-7491(00)00053-1
Cohen AC, Travaglia CN, Bottini R, Piccoli PN (2009) Participation of abscisic acid and gibberellins produced by endophytic Azospirillum in the alleviation of drought effects in maize. Botany 87:455–462. https://doi.org/10.1139/B09-023
Creus C, Sueldo RJ, Barassi CA (2004) Water relations and yield in Azospirillum-inoculated wheat exposed to drought in the field. Can J Bot 82:273–281
Donald AH, Robert O (1998) Determination of total nitrogen in plant tissue. In: Kalra YP (ed) Handbook and reference methods for plant analysis. CRC Press
Elekhtyar N (2015) Efficiency of Pseudomonas fluorescens as plant growth-promoting rhizobacteria (PGPR) for the enhancement of seedling vigor, nitrogen uptake, yield and its attributes of rice (Oryza sativa L.). Int J Sci Res Agric Sci 2:57–67
El-Hendawy SE, El-Lattief EAA, Ahmed MS, Schmidhalter U (2008) Irrigation rate and plant density effects on yield and water use efficiency of drip-irrigated corn. Agric Water Manag 95:836–844. https://doi.org/10.1016/j.agwat.2008.02.008
Falagán N, Artés F, Artés-Hernández F et al (2015) Comparative study on postharvest performance of nectarines grown under regulated deficit irrigation. Postharvest Biol Technol 110:24–32. https://doi.org/10.1016/j.postharvbio.2015.07.011
FAOSTAT (2018) Food and agriculture data. Food and Agriculture Organization
Fernández JE, Alcon F, Diaz-espejo A et al (2020) Water use indicators and economic analysis for on-farm irrigation decision: a case study of a super high density olive tree orchard. Agric Water Manag 237:106074. https://doi.org/10.1016/j.agwat.2020.106074
García de Salamone IE, Funes JM, Di Salvo LP et al (2012) Inoculation of paddy rice with Azospirillum brasilense and Pseudomonas fluorescens: Impact of plant genotypes on rhizosphere microbial communities and field crop production. Appl Soil Ecol 61:196–204. https://doi.org/10.1016/j.apsoil.2011.12.012
Geerts S, Raes D (2009) Deficit irrigation as an on-farm strategy to maximize crop water productivity in dry areas. Agric Water Manag 96:1275–1284. https://doi.org/10.1016/j.agwat.2009.04.009
Getahun A, Muleta D, Assefa F, Kiros S (2020) Plant growth-promoting rhizobacteria isolated from degraded habitat enhance drought tolerance of acacia (Acacia abyssinica Hochst. ex Benth.) seedlings. Int J Microbiol 2020:8897998. https://doi.org/10.1155/2020/8897998
Grover M, Ali SZ (2011) Role of microorganisms in adaptation of agriculture crops to abiotic stresses Role of microorganisms in adaptation of agriculture crops to abiotic stresses. World J Microbiol Biotechnol. https://doi.org/10.1007/s11274-010-0572-7
Guimarães CM, Stone LF, Rangel PHN, Silva ACL (2013) Tolerance of upland rice genotypes to water deficit [Tolerância à deficiência hídrica de genótipos de arroz de terras altas]. Rev Bras Eng Agric e Ambient 17:805–810
Hayat S, Ali B, Hasan SA, Ahmad A (2007) Brassinosteroid enhanced the level of antioxidants under cadmium stress in Brassica juncea. Environ Exp Bot 60:33–41
Hoekstra AY, Chapagain AK, Aldaya MM, Mekonnen MM (2011) The water footprint assessment manual: setting the global standard. Routledge. https://doi.org/10.4324/9781849775526
Hussain MB, Zahir ZA, Asghar HN, Asgher M (2014) Can catalase and exopolysaccharides producing rhizobia ameliorate drought stress in wheat? Int J Agric Biol 16:3–13
Jägermeyr J, Gerte D, Heinke J, Schaphoff S, Kummu M, Lucht W (2015) Water savings potentials of irrigation systems:global simulation of processes and linkages. Hydrol Earth Syst Sci 19:3073–3091
Jensen ME (1983) Design and operation of farm irrigation systems. American Society of Agricultural Engineers, p 827
Kang SM, Radhakrishnan R, Khan AL et al (2014) Gibberellin secreting rhizobacterium, Pseudomonas putida H-2-3 modulates the hormonal and stress physiology of soybean to improve the plant growth under saline and drought conditions. Plant Physiol Biochem 84:115–124. https://doi.org/10.1016/j.plaphy.2014.09.001
Kim YC, Glick BR, Bashan R, Ryu C (2012) Enhancement of plant drought tolerance by microbes. In: Aroca R (ed) Plant responses to drought stress. Springer
Koch E (1997) Screening of rhizobacteria for antagonistic activity against Pythium ultimum on cucumber and kale. J Plant Dis Prot 104:353–361
Kruzhilin IP, Doubenok NN, Ganiev MA, Abdou NM, MeliKhov VV, Bolotin AG, Rodin KA (2015) Water-saving technology of drip irrigated aerobic rice cultivation. J Isvestiya 3:47–56
Kruzhilin IP, Doubenok NN, Ganiev MA et al (2016) Combination of the natural and anthropogenically-controlled conditions for obtaining various rice yield using drip irrigation systems. Russ Agric Sci 42:454–457. https://doi.org/10.3103/s1068367416060173
Kumar A, Dixit S, Ram T et al (2014) Breeding high-yielding drought-tolerant rice: genetic variations and conventional and molecular approaches. J Exp Bot 65:6265–6278. https://doi.org/10.1093/jxb/eru363
Li FM, Song QH, Liu HS et al (2001) Effects of pre-sowing irrigation and phosphorus application on water use and yield of spring wheat under semi-arid conditions. Agric Water Manag 49:173–183. https://doi.org/10.1016/S0378-3774(01)00087-7
Liu F, Xing S, Ma H et al (2013) Cytokinin-producing, plant growth-promoting rhizobacteria that confer resistance to drought stress in Platycladus orientalis container seedlings. Appl Microbiol Biotechnol 97:9155–9164. https://doi.org/10.1007/s00253-013-5193-2
Loper JE, Schroth MN (1986) Influence of bacterial sources of indole-3-acetic acid on root elongation of sugar beet. Phytopathology 76:386–389
Maxwell K, Johnson GN (2000) Chlorophyll fluorescence—a practical guide. J Exp Bot 51:659–668. https://doi.org/10.1093/jxb/51.345.659
McCauley GN (1990) Sprinkler vs. flood irrigation in traditional rice production regions of Southeast Texas. Agron J 82:677–683
Meyer JM, Abdallah MA (1978) The fluorescent pigment of Pseudomonas fluorescens: Biosynthesis, purification and physicochemical properties. J Gen Microbiol 107:319–328. https://doi.org/10.1099/00221287-107-2-319
Palanog AD, Swamy BPM, Shamsudin NAA et al (2014) Grain yield QTLs with consistent-effect under reproductive-stage drought stress in rice. Field Crop Res 161:46–54. https://doi.org/10.1016/j.fcr.2014.01.004
Palli R (2005) Effect of plant growth-promoting rhizobacteria on canola (Brassica napus L.) and lentil (Lens culinaris Medik) plants. Thesis, Master of Science, Department of Applied Microbiology and Food Science, University of Saskatchewan, Saskatoon, Canada
Pantuwan G, Fukai S, Cooper M et al (2002) Yield response of rice (Oryza sativa L.) genotypes to drought under rainfed lowlands 2. Selection of drought resistant genotypes. Field Crop Res 73:169–180. https://doi.org/10.1016/S0378-4290(01)00195-2
Pejic B, Cupina B, Dimitrijevic M et al (2011) Response of sugar beet to soil water deficit. Rom Agric Res 28:151–155
Poudel M, Mendes R, Costa L, Bueno CG, Meng Y, Folimonova SY, Garrett KA, Martins SJ (2021) The role of plant-associated bacteria, fungi, and viruses in drought stress mitigation. Front Microbiol 12:743512. https://doi.org/10.3389/fmicb.2021.743512
Premachandra GS, Saneoka H, Ogata S (1990) Cell membrane stability, an indicator of drought tolerance, as affected by applied nitrogen in soyabean. J Agric Sci. https://doi.org/10.1017/S0021859600073925
Quampah A, Wang RM, Shams H et al (2011) Improving water productivity by potassium application in various rice genotypes. Int J Agric Biol 13:9–17
Rady MM, AbdEl-Mageed TA, Abdurrahman HA, Mahdi AH (2016) Humic acid application improves field performance of cotton (Gossypium barbadense L.) under saline conditions. J Anim Plant Sci 26:487–493
Rady MM, Boriek SHK, Abd El-Mageed TA et al (2021a) Exogenous gibberellic acid or dilute bee honey boosts drought stress tolerance in vicia faba by rebalancing osmoprotectants, antioxidants, nutrients, and phytohormones. Plants 10:1–23. https://doi.org/10.3390/plants10040748
Rady MOA, Semida WM, Howladar SM, Abd El-Mageed TA (2021b) Raised beds modulate physiological responses, yield and water use efficiency of wheat (Triticum aestivum L.) under deficit irrigation. Agric Water Manag 245:106629
Ram PC, Maclean JL, Dawe DC et al (2003) Rice almanac, 3rd edn. Ann Bot 92(5):739. https://doi.org/10.1093/aob/mcg189
Ramamoorthy V, Raguchander T, Samiyappan R (2002) Induction of defense-related proteins in tomato roots treated with Pseudomonas fluorescens Pf1 and Fusarium oxysporum f. sp. lycopersici. Plant Soil 239:55–68
Renwick A, Campbel L, Coe S (1991) Assessment of in vivo screening systems for potential biocontrol agents of Gaeumannomyces graminis. Plant Pathol 40:524–532
Rodriguez IR, Miller GL (2000) Using a chlorophyll meter to determine the chlorophyll concentration, nitrogen concentration, and visual quality of St. Augustinegrass Hortsci 35:751–754
Rodriguez H, Gonzalez T, Goire I, Bashan Y (2004) Gluconic acid production and phosphate solubilization by the plant growth-promoting bacterium Azospirillum spp. Naturwissenschaften 91:552–555. https://doi.org/10.1007/s00114-004-0566-0
Samaniego-Gámez BY, Garruña R, Tun-Suárez JM et al (2016) Bacillus spp. Inoculation improves photosystem II efficiency and enhances photosynthesis in pepper plants. Chil J Agric Res 76:409–416. https://doi.org/10.4067/S0718-58392016000400003
Saravanan VS, Subramoniam SR, Raj SA (2004) Assessing in vitro solubilization potential of different zinc solubilizing bacterial (ZSB) isolates. Braz J Microbiol 35:121–125. https://doi.org/10.1590/S1517-83822004000100020
Selvakumar G, Panneerselvam PGA (2012) Bacterial mediated alleviation of abiotic stress in crops. In: Maheshwari DK (ed) Bacteria in agrobiology: stress management. Springer, Berlin, pp 205–224
Semida WM, Abd El-Mageed TA, Howladar SM (2014) A novel organo-mineral fertilizer can alleviate negative effects of salinity stress for eggplant production on reclaimed saline calcareous soil. ISHS Acta Hortic 1034:493–499
Semida WM, Abdelkhalik A, Rady MOA et al (2020) Exogenously applied proline enhances growth and productivity of drought stressed onion by improving photosynthetic efficiency, water use efficiency and up-regulating osmoprotectants. Sci Hortic 272:109580. https://doi.org/10.1016/j.scienta.2020.109580
Semida WM, Abd El-Mageed TA, Abdelkhalik A et al (2021a) Selenium modulates antioxidant activity, osmoprotectants, and photosynthetic efficiency of onion under saline soil conditions. Agronomy 11:855. https://doi.org/10.3390/agronomy11050855
Semida WM, Abdelkhalik A, Mohamed G et al (2021b) Foliar application of zinc oxide nanoparticles promotes drought stress tolerance in eggplant (Solanum melongena L.). Plants 10:421
Shekoofa A, Sinclair T (2018) Aquaporin activity to improve crop drought tolerance. Cells 7:123. https://doi.org/10.3390/cells7090123
Sivapalan S (2015) Water Balance of Flooded Rice in the Tropics. In: Javaid MS (ed) Irrigation and drainage—sustainable strategies and systems. Intech Open. https://doi.org/10.5772/59043
Soil Survey Staff (1999) Soil taxonomy. A basic system of soil classification for making sand interpreting soil surveys. Agriculture Handbook no. 466, 2nd edn. USDA
Steduto P, Hsiao TC, Fereres E, Raes D (2012) Crop yield response to water. FAO
Timmusk S, El-daim IAA, Copolovici L et al (2014) Drought-tolerance of wheat improved by rhizosphere bacteria from harsh environments: enhanced biomass production and reduced emissions of stress volatiles. PLoS ONE. https://doi.org/10.1371/journal.pone.0096086
Tuong TP, Bouman BAM, Mortimer M (2005) More rice, less water—integrated approaches for increasing water productivity in irrigated rice-based systems in Asia. Plant Prod Sci 8:231–241. https://doi.org/10.1626/pps.8.231
Vickers ACR (2002) Handbook of water use and conservation. Water Plow
Vurukonda SS, Vardharajula S, Shrivastava M, SkZ A (2016) Enhancement of drought stress tolerance in crops by plant growth promoting rhizobacteria. Microbiol Res 184:13–24
Wang F, Kang S, Du T et al (2011) Determination of comprehensive quality index for tomato and its response to different irrigation treatments. Agric Water Manag 98:1228–1238. https://doi.org/10.1016/j.agwat.2011.03.004
Wang CJ, Yang W, Wang C et al (2012) Induction of drought tolerance in cucumber plants by a consortium of three plant growth-promoting rhizobacterium strains. PLoS ONE 7:1–10. https://doi.org/10.1371/journal.pone.0052565
Wu N, Guan Y, Shi Y (2011) Effect of water stress on physiological traits and yield in rice backcross lines after anthesis. Energy Procedia 5:255–260. https://doi.org/10.1016/j.egypro.2011.03.045
Yang J, Kloepper JW, Ryu C (2009) Rhizosphere bacteria help plants tolerate abiotic stress. Trends Plant Sci 14:1–4
Yang X, Wang B, Chen L et al (2019) The different influences of drought stress at the flowering stage on rice physiological traits, grain yield, and quality. Sci Rep 9:1–12. https://doi.org/10.1038/s41598-019-40161-0
Yogendra SG, Singh US, Sharma AK (2015) Bacterial mediated amelioration of drought stress in drought tolerant and susceptible cultivars of rice (Oryza sativa L.). African J Biotechnol 14:764–773. https://doi.org/10.5897/ajb2015.14405
Yuan S, Linquist BA, Wilson LT et al (2021) Sustainable intensification for a larger global rice bowl. Nat Commun 12:7163. https://doi.org/10.1038/s41467-021-27424-z
Zhang W, Xie Z, Zhang X et al (2019) Growth-promoting bacteria alleviates drought stress of G. uralensis through improving photosynthesis characteristics and water status. J Plant Interact 14:580–589. https://doi.org/10.1080/17429145.2019.1680752
Acknowledgements
Not applicable.
Funding
Open access funding provided by The Science, Technology & Innovation Funding Authority (STDF) in cooperation with The Egyptian Knowledge Bank (EKB).
Author information
Authors and Affiliations
Contributions
TAA, SAA and SA conceived and designed the experiment. TAA, NA and SAA handled the experiment and measured physiological indicators. TAA, and MTE analyzed the data and wrote the paper. All authors read and approved the final manuscript.
Corresponding author
Ethics declarations
Ethics Approval and Consent to Participate
Not applicable.
Consent for Publication
Not applicable.
Competing interests
The authors declare that they have no competing interests.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
About this article
Cite this article
Abd El-Mageed, T.A., Abd El-Mageed, S.A., El-Saadony, M.T. et al. Plant Growth-Promoting Rhizobacteria Improve Growth, Morph-Physiological Responses, Water Productivity, and Yield of Rice Plants Under Full and Deficit Drip Irrigation. Rice 15, 16 (2022). https://doi.org/10.1186/s12284-022-00564-6
Received:
Accepted:
Published:
DOI: https://doi.org/10.1186/s12284-022-00564-6