Institute of Plant Science and Resources, Okayama University, 2-20-1 Chuo, Kurashiki 710-0046, Japan.
Faculty of Agronomy, University of Agriculture and Forestry, Hue University, Hue 530000, Vietnam.
Int J Mol Sci. 2020 Sep 27;21(19):7135. doi: 10.3390/ijms21197135.
Some plasma membrane intrinsic protein (PIP) aquaporins can facilitate ion transport. Here we report that one of the 12 barley PIPs (PIP1 and PIP2) tested, , facilitated cation transport when expressed in oocytes. -associated ion currents were detected with Na and K, but not Cs, Rb, or Li, and was inhibited by Ba, Ca, and Cd and to a lesser extent Mg, which also interacted with Ca. Currents were reduced in the presence of K, Cs, Rb, or Li relative to Na alone. Five HvPIP1 isoforms co-expressed with inhibited the ion conductance relative to alone but HvPIP1;3 and HvPIP1;4 with maintained the ion conductance at a lower level. water permeability was similar to that of a C-terminal phosphorylation mimic mutant S285D, but S285D showed a negative linear correlation between water permeability and ion conductance that was modified by a kinase inhibitor treatment. transcript abundance increased in barley shoot tissues following salt treatments in a salt-tolerant cultivar Haruna-Nijo, but not in salt-sensitive I743. There is potential for to be involved in barley salt-stress responses, and could facilitate both water and Na/K transport activity, depending on the phosphorylation status.
一些质膜内在蛋白 (PIP) 水通道蛋白可以促进离子转运。本文报道了在卵母细胞中表达的 12 种大麦 PIP 中的 1 种 (PIP1 和 PIP2) 时，能够促进阳离子转运。检测到与 相关的离子电流，可被 Na 和 K 但不能被 Cs、Rb 或 Li 激活，且被 Ba、Ca 和 Cd 以及 Mg 抑制，Mg 也与 Ca 相互作用。与单独的 Na 相比，K、Cs、Rb 或 Li 的存在会降低电流。与 共表达的五种 HvPIP1 同工型抑制了离子电导，而 HvPIP1;3 和 HvPIP1;4 与 维持较低水平的离子电导。 水通透性与 C 端磷酸化模拟突变体 S285D 相似，但 S285D 的水通透性与离子电导之间存在负线性相关，这种相关性可被激酶抑制剂处理改变。盐处理后，耐盐品种 Haruna-Nijo 的大麦茎组织中 转录本丰度增加，但在盐敏感品种 I743 中没有增加。 可能参与大麦盐胁迫反应，并且 可以根据磷酸化状态促进水和 Na/K 转运活性。
