Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, 611130, Sichuan, China.
Joint International Research Laboratory of Crop Resources and Genetic Improvement, Sichuan Agricultural University, Wenjiang, 611130, Sichuan, China.
BMC Genomics. 2019 Mar 12;20(1):210. doi: 10.1186/s12864-019-5589-1.
The SnRK2s (Plant specific protein kinase) are involved in various biological processes, such as plant defense and environmental challenges. In Arabidopsis, AtSnRK2s regulate the expression of some metal transporters. For example, AtSnRK2.4 plays a role in the regulation of Arabidopsis tolerance to Cd; AtSnRK2.2 and AtSnRK2.3 are involved in Cd uptake and translocation. However, the functions of their homologs, TpSnRK2.10 and TpSnRK2.11 from dwarf Polish wheat are unknown.
TpSnRK2.11 encodes a cytoplasmic protein. TpSnRK2.10 and TpSnRK2.11 have different expression patterns at different growth stages. Expression of TpSnRK2.10 increased yeast's sensitivity to Cd; conversely, expression of TpSnRK2.11 enhanced yeast's tolerance to Cd. Overexpression of TpSnRK2.10 or TpSnRK2.11 did not affect Cd sensitivity in Arabidopsis, but significantly increased Cd accumulation in roots and shoots, and Cd translocation from roots to shoots. While, Fe accumulation was significantly increased in roots but decreased in shoots by overexpression of TpSnRK2.10; opposite results were observed in TpSnRK2.11-overexpressing lines. Subcellular distribution analysis found that overexpression of TpSnRK2.10 and TpSnRK2.11 increased Cd concentration in cell wall and organelle fractions of roots and shoots; meanwhile, they also differentially influenced Fe distribution.
These results indicated that TpSnRK2.10 and TpSnRK2.11 are involved in the uptakes and the translocations of Cd and Fe, possibly by regulating the expression of AtNRAMP1 and AtHMA4, and other genes involved in the synthesis of phytochelatins or hemicellolosic polysaccharides.
SnRK2s（植物特异性蛋白激酶）参与多种生物学过程，如植物防御和环境挑战。在拟南芥中，AtSnRK2s 调节一些金属转运蛋白的表达。例如，AtSnRK2.4 在调节拟南芥对 Cd 的耐受性方面发挥作用；AtSnRK2.2 和 AtSnRK2.3 参与 Cd 的摄取和转运。然而，其同源物 TpSnRK2.10 和 TpSnRK2.11 来自矮波兰小麦的功能尚不清楚。
TpSnRK2.11 编码细胞质蛋白。TpSnRK2.10 和 TpSnRK2.11 在不同生长阶段的表达模式不同。TpSnRK2.10 的表达增加了酵母对 Cd 的敏感性；相反，TpSnRK2.11 的表达增强了酵母对 Cd 的耐受性。TpSnRK2.10 或 TpSnRK2.11 的过表达均不影响拟南芥对 Cd 的敏感性，但显著增加了根和地上部的 Cd 积累和 Cd 从根向地上部的转运。而过表达 TpSnRK2.10 会导致根中 Fe 积累显著增加，而地上部减少；而在 TpSnRK2.11 过表达系中观察到相反的结果。亚细胞分布分析发现，TpSnRK2.10 和 TpSnRK2.11 的过表达增加了根和地上部细胞壁和细胞器部分的 Cd 浓度；同时，它们也对 Fe 分布有不同的影响。
这些结果表明，TpSnRK2.10 和 TpSnRK2.11 参与 Cd 和 Fe 的摄取和转运，可能通过调节 AtNRAMP1 和 AtHMA4 以及其他参与合成植物螯合肽或半纤维素多糖的基因的表达来实现。
