Table 2.
Role of membrane transporters in abiotic stress tolerance.
| Abiotic Stress | Transporter Protein | Plant Species | Tissue/Organ | Biological Role | Ref. |
|---|---|---|---|---|---|
| Salt | AlHKT2;1 | A. lagopoides | Leaf/shoot /root | Na+/K+ co-transporter gene prevents plants from salinity stress | [62] |
| OsCam1–1 | O. sativa | Leaf | It is involved in signaling, hormone-mediated regulation, transcription, lipid, carbohydrate and secondary metabolism, photosynthesis, glycolysis, TCA and glyoxylate cycle under salt stress | [111] | |
| AtFC1 | A. thaliana | Roots, cotyledon, root, shoot, leaf and flower | It enhances K+ accumulation and prevents cell membrane lysis; it also upregulates the expression levels of NHX1 and AVP1 | [56] | |
| ATG8 | A. thaliana | Root/cortex cells | It plays a role in nutrient remobilization following salt induced autophagy | [112] | |
| PRE1/AAP1 | A. thaliana | Root | It enhanced uptake and transportation of proline and prevented proline degradation | [113] | |
| OsAKT1 | O. sativa | Root/elongation zone and shoot | Retain K+ in root to balance Na+/K+ ratio | [59] | |
| ZmHKT1;5 | Z. mays | Leaf | Balances Na+/K+ ratio and improves plant growth | [60] | |
| Drought | CrPIP2;3 | A. thaliana | Germinating seed, seedling and root | It plays pivotal roles in maintaining water and nutrition homeostasis | [67] |
| PIP1;5/PIP2;3 | S. bicolor | Root and leaf | Maintains WUE | [66] | |
| H+-ATPase | C. sinensis | Leaf | Maintenance of K+ homeostasis in mesophyll cells | [114] | |
| OsHAK1 | O. sativa | Root and shoot | Involved in K acquisition, translocation and homeostasis by upregulating OsTPKb and OsAKT1 | [68] | |
| OsNAC5/6/9/10 | O. sativa | Root | Target genes were involved in transmembrane/transporter activity, carbohydrate metabolism, vesicle and plant hormones | [115] | |
| Cold | HSP70-16/VDAC3 | A. thaliana | Seed, endosperm and embryo | Activation of the opening of VDAC3 ion channels, ABA transportation from endosperm to embryo and then inhibits seed germination | [116] |
| CsSWEET16 | A. thaliana | Leaf and flower buds | Sugar transport across vacuoles and cold tolerance | [42] | |
| TsABCG11 | A. thaliana | Root, stem leaf, rosette leaf, flower and silique | Thickening the leaf cuticle layer (wax and cutin) by exporting cuticle lipid molecules to prevent plants from cold stress | [92] | |
| AlTMP2 | A. littoralis | Root and leaf | Improves membrane stability | [117] | |
| AtPIP1;4/AtPIP2;5 | A. thaliana | Root and shoot | Plays a role in cold acclimation and freezing tolerance | [91] | |
| VAB3/NHX2/NHX5 | E. botschantzevii | Shoot | Cold acclimation | [118] | |
| SOS1/VP2/HA3 | E. salsugineum | Shoot | Cold acclimation | [118] | |
| Heat | TaZnFP | A. thaliana | 14-day seedling | Larger primary roots, more lateral branches, increased in leaf size and numbers, promotes early flowering and enhanced fresh biomass | [16] |
| P4-type ATPase | A. thaliana | 14-day seedling, rosette leaf, flower (stamen and pistil) and silique | It is involved in flipping lipids that cope with heat stress | [76] | |
| OsSUS | O. sativa | Flag leaf, stem-sheath and spikelet | It acts as a signalling molecule to mediate source and sink relationships under heat stress | [119] | |
| HMs | TpNRAMP3 | T. polonicum, Polish wheat | Leaf and root | Transport Cd, Co and Mn but does not transport Fe or Zn, which induced HM toxicity | [21] |
| PtABCC1 | P. trichocarpa/A. thaliana | Root | It enhances the accumulation and tolerance to Hg | [101] | |
| PtoABCG36 | A. thaliana | Leaf/stem/root | It acts as an extrusion pump to decrease Cd uptake and enhance tolerance to Cd stress | [102] | |
| PtoABCG36 | O. sativa | Root and shoot | Export Cd from root and enhance Cd tolerance | [103] | |
| OsSMP1 | O. sativa | Leaf | Acts as a positive regulator of Cd and Cu tolerance via ABA-dependent pathway | [100] | |
| LmSAP | N. tabacum | Leaf and root | Enhanced accumulation of Cu, Cd and Mn, decreased H2O2 content, upregulated SOD, POD and CAT activities and stress related metallothioneins, i.e., Met1-5 | [120] | |
| AtCNGC1/10/13/19 | A. thaliana | Primary root and seedling | Plays a role Pb toxicity by reducing its uptake | [121] | |
| AtCNGC11/13/16/20 | A. thaliana | Primary root and seedling | Plays a role Cd toxicity by reducing its uptake | [121] | |
| SaNramp6 | A. thaliana | Root, stem and leaf | Improves Cd accumulation | [122] | |
| OsLCT1/OsHMA2/ OsZIP3 |
O. sativa | Root and shoot | Co-expression of HM transporters improved root and shoot lengths under Zn and Cd stress | [123] |