Table 1 Identified and potential transporters and channels for Se uptake, transport, and subcellular distribution

Selenate uptake (group 1 sulfate transporters)

AtSultr1;1

Root hairs, epidermis, and cortical cell layers (Takahashi et al. 2000)

Sultrl;2

Root cortex, root tip and lateral roots (Shibagaki et al. 2002; Yoshimoto et al. 2002)

AtSultr1;3^*

Sieve element-companion cell complexes of the phloem in cotyledons and roots (Yoshimoto et al. 2003)

OsSultr1;1-OsSultr1;3

Root (Kumar et al. 2011; Réthoré et al. 2020)

Selenate transport (group 2 sulfate transporters)

AtSultr2;1

Xylem parenchyma cells of leaves and roots (Takahashi et al. 2000)

AtSultr2;2

Root phloem and leaf vascular bundle sheath cells (Takahashi et al. 2000)

OsSultr2;1-OsSultr2;2

Vascular tissues (Dixit et al. 2015)

Selenate transport (channels)

Anion channels

Xylem parenchyma cells (Gilliham and Tester 2005)

Selenate subcellular distribution (group 3 sulfate transporters)

AtSultr3;1-AtSultr3;5

Chloroplast (Hawkesford 2003; Buchner et al. 2004; Cao et al. 2013)

OsSultr3;1-OsSultr3;6

Selenate subcellular distribution (group 4 sulfate transporters)

AtSultr4;1-AtSultr4;2

Tonoplast (Hawkesford 2003; Buchner et al. 2004)

OsSultr4;1

Uptake (group 1 phosphate transporters)

OsPht1;2

Root epidermal cells and steles in primary and lateral roots (Zhang et al. 2014)

OsPht1;8

Root tips, lateral roots, leaves, stamens, caryopses (Jia et al. 2011)

Uptake (NIP subfamily)

OsNIP2;1

Plasma membrane of the distal side of both exodermis and endodermis cells (Ma et al. 2006)

SeMet transport (PTR family)

OsNRT1.1B

Vascular tissues of roots, leaf sheaths, leaf blades and culms (Hu et al. 2015)

Subcellular distribution (group 4 phosphate transporters)

AtPht4;1-AtPht4;5

Plastid envelope (Guo et al. 2008)

OsPht4;1-OsPht4;4

Inner chloroplast membrane (Li et al. 2020)

Subcellular distribution (group 2 phosphate transporters)

OsPht2;1

Chloroplast (Liu et al. 2020)

Subcellular distribution (group 5 phosphate transporters or SPX-MFS proteins)

AtSPX-MFS 1–3

Tonoplast (Liu et al. 2020)

OsSPX-MFS 1–3

Tonoplast (Wang et al. 2012, 2015; Xu et al. 2019)