Ji Ruijie, Zhou Liming, Liu Jinglong, Wang Yuan, Yang Lei, Zheng Qinsong, Zhang Chi, Zhang Bin, Ge Haiman, Yang Yonghua, Zhao Fugeng, Luan Sheng, Lan Wenzhi
College of Resources and Environmental Science, Key Laboratory of Marine Biology, Nanjing Agricultural University, Nanjing, Jiangsu, China.
College of Life Sciences, Fujian Agriculture and Forestry University, Fujian, Fuzhou, China.
PLoS One. 2017 Mar 15;12(3):e0173681. doi: 10.1371/journal.pone.0173681. eCollection 2017.
Although arsenite [As(III)] is non-essential and toxic for plants, it is effectively absorbed through various transporters into the roots. Here we identified a calcium-dependent protein kinase (CPK31) response for As(III) tolerance in Arabidopsis. We identified CPK31 as an interacting protein of a nodulin 26-like intrinsic protein (NIP1;1), an aquaporin involved in As(III) uptake. Similarly to the nip1;1 mutants, the loss-of-function mutants of CPK31 improved the tolerance against As(III) but not As(V), and accumulated less As(III) in roots than that of the wild-type plants. The promoter-β-glucuronidase and quantitative Real-Time PCR analysis revealed that CPK31 displayed overlapping expression profiles with NIP1;1 in the roots, suggesting that they might function together in roots. Indeed, the cpk31 nip1;1 double mutants exhibited stronger As(III) tolerance than cpk31 mutants, but similar to nip1;1 mutants, supporting the idea that CPK31 might serve as an upstream regulator of NIP1;1. Furthermore, transient CPK31 overexpression induced by dexamethasone caused the decrease in As(III) tolerance of transgenic Arabidopsis lines. These findings reveal that CPK31 is a key factor in As(III) response in plants.
尽管亚砷酸盐[As(III)]对植物而言并非必需且具有毒性，但它可通过多种转运蛋白被有效吸收进入根部。在此，我们鉴定出拟南芥中一种依赖钙的蛋白激酶（CPK31）对As(III)耐受性的响应。我们确定CPK31是一种类结节蛋白26内在蛋白（NIP1;1）的相互作用蛋白，NIP1;1是一种参与As(III)吸收的水通道蛋白。与nip1;1突变体类似，CPK31的功能缺失突变体提高了对As(III)而非As(V)的耐受性，且根部积累的As(III)比野生型植物少。启动子-β-葡萄糖醛酸酶及定量实时PCR分析表明，CPK31与NIP1;1在根部呈现重叠的表达谱，这表明它们可能在根部共同发挥作用。实际上，cpk31 nip1;1双突变体表现出比cpk31突变体更强的As(III)耐受性，但与nip1;1突变体相似，这支持了CPK31可能作为NIP1;1上游调节因子的观点。此外，地塞米松诱导的CPK31瞬时过表达导致转基因拟南芥品系对As(III)的耐受性降低。这些发现揭示了CPK31是植物对As(III)响应中的关键因子。
