Table 2 Pollen inactivation genes and their pollen killing activities in the maintainers
From: Establishment and Advances of Third-Generation Hybrid Rice Technology: A Review
Pollen inactivation gene | Mechanism | Transgenic pollen escape rate | Application crop | Reference |
|---|---|---|---|---|
α-amylase gene ZmAA1 | Degrade the starch in the pollen to inactivate pollen. | 0.01 − 0.08% | Rice, Maize, foxtail millet | (Wu et al. 2016; Chang et al. 2016; Qi et al. 2020; Zhang et al. 2023a) |
CMS-HL gene orfH79 | The orfH79 encoded protein is toxic to mitochondria and disables the pollen. | 0.14 − 0.17% | Rice | (Song et al. 2021) |
DNA adenine methyltransferase gene Dam | Dam encoded protein catalyzes the methylation of adenine residues in the pollen DNA, leading to pollen lethality. | Almost none | Maize | (Zhang et al. 2018a) |
Unilateral cross-incompatibility (UCI) gene ZmGa1F | Proper pollen-specific ZmGa1F expression disrupts pollen tube growth and results in non-fertilization | Almost none | Maize | (Cai et al. 2023) |