Coronatine promotes maize water uptake by directly binding to the aquaporin ZmPIP2;5 and enhancing its activity
Coronatine promotes maize water uptake by directly binding to the aquaporin ZmPIP2;5 and enhancing its activity
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DOI：
10.1111/jipb.13432
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发表时间：
2023-01-13
影响因子：
11.4
通讯作者：
Duan, Liusheng
中科院分区：
文献类型：
--
作者：
He, Rui;Su, Huiqing;Duan, Liusheng
水分吸收对于作物生长发育和耐旱性至关重要。水通道水通道蛋白（AQP）在植物水分吸收过程中起着重要作用。在这里，我们发现，茉莉酸类似物，冠菌素（COR），增强玉米（玉米）根水分吸收能力在人工缺水条件下。COR处理诱导AQP基因质膜内在蛋白2;5（ZmPIP 2;5）的表达。体内和体外实验表明，COR也直接作用于ZmPIP 2;5，以提高玉米和爪蟾卵母细胞的水分吸收。与野生型植物相比，在高渗条件下生长的根的叶水势和水力传导率在ZmPIP 2;5-过表达株系中较高，在ZmPIP 2;5敲除突变体中较低。基于ZmPIP 2;5与其他PIP 2的比较，我们预测COR可能结合于ZmPIP 2;5的E环中的功能位点。我们证实了这一预测的表面等离子体共振技术和微量热泳试验，并表明，删除结合基序大大降低COR结合。我们确定N241残基为COR特异性结合位点，其可以激活AQP四聚体的通道并增加水转运活性，这可能有助于高渗胁迫下的水摄取。
Water uptake is crucial for crop growth and development and drought stress tolerance. The water channel aquaporins (AQP) play important roles in plant water uptake. Here, we discovered that a jasmonic acid analog, coronatine (COR), enhanced maize (Zea mays) root water uptake capacity under artificial water deficiency conditions. COR treatment induced the expression of the AQP gene Plasma membrane intrinsic protein 2;5 (ZmPIP2;5). In vivo and in vitro experiments indicated that COR also directly acts on ZmPIP2;5 to improve water uptake in maize and Xenopus oocytes. The leaf water potential and hydraulic conductivity of roots growing under hyperosmotic conditions were higher in ZmPIP2;5-overexpression lines and lower in the zmpip2;5 knockout mutant, compared to wild-type plants. Based on a comparison between ZmPIP2;5 and other PIP2s, we predicted that COR may bind to the functional site in loop E of ZmPIP2;5. We confirmed this prediction by surface plasmon resonance technology and a microscale thermophoresis assay, and showed that deleting the binding motif greatly reduced COR binding. We identified the N241 residue as the COR-specific binding site, which may activate the channel of the AQP tetramer and increase water transport activity, which may facilitate water uptake under hyperosmotic stress.