The ABA receptor gene MdPYL9 confers tolerance to drought stress in transgenic apple (Malus domestica)
The ABA receptor gene MdPYL9 confers tolerance to drought stress in transgenic apple (Malus domestica)
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阿坝受体基因MdPYL9对转基因苹果耐旱性的影响
DOI：
10.1016/j.envexpbot.2021.104695
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发表时间：
2021-11
影响因子：
5.7
通讯作者：
Jie Yang;Min Wang;Shasha Zhou;Bingyao Xu;Peihong Chen;F. Ma;Ke Mao
中科院分区：
文献类型：
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作者：
Jie Yang;Min Wang;Shasha Zhou;Bingyao Xu;Peihong Chen;F. Ma;Ke Mao
脱落酸（阿坝）是植物生长发育和对各种非生物胁迫反应的重要激素。Pyrabactin Resistance 1（PYR 1）/PYR 1-Like（PYL）/Regulatory Component of阿坝Receptor（RCAR）family proteins（PYL）是已在许多植物物种中研究的阿坝受体。然而，这些基因在调节苹果耐旱性的详细功能研究还没有报道。在这里，我们分离出的阿坝受体PYL 9在拟南芥，MdPYL 9，从苹果（Malusaritica）的同源物，并分析其在调节转基因苹果植物的耐旱性的作用。基因结构和蛋白质序列分析表明，MdPYL 9与AtPYL 9具有很高的相似性。蛋白质序列比较和3D结构预测确定了几个保守的基序和残基，这是重要的阿坝结合在MdPYL 9，包括螺旋握结构和门和锁环。表达分析表明，干旱处理显著诱导了MdPYL 9的表达。与野生型相比，MdPYL 9基因的过表达增强了转基因苹果对干旱胁迫的耐受性，表现为较高的光合速率和相对含水量，较低的MDA含量和电解质渗漏率。结果表明，在干旱胁迫下，MdPYL 9基因过量表达可促进活性氧（ROS）的清除，从而减轻氧化损伤。酵母双杂交分析表明，MdPYL 9与苹果PP 2C家族A亚群成员（PP 2CAs）之间存在ABA依赖和ABA非依赖的相互作用。表达分析表明，两个PP 2CA基因MdHAI 1和MdHAI 2在干旱条件下高表达，而在正常条件下不表达。这些结果提供了新的见解，可以用来帮助未来的研究MdPYLs的功能和机制，他们调节苹果耐旱性。
Abscisic acid (ABA) is an important phytohormone for plant growth, development, and the response to various types of abiotic stress. Pyrabactin Resistance 1 (PYR1)/PYR1-Like (PYL)/Regulatory Component of ABA Receptor (RCAR) family proteins (PYLs) are ABA receptors that have been studied in many plant species. However, no detailed functional studies of these genes in regulating apple drought tolerance have been reported. Here, we isolated a homolog of the ABA receptor PYL9 in Arabidopsis, MdPYL9, from apple (Malusdomestica) and analyzed its role in regulating drought tolerance in transgenic apple plants. Gene structure and protein sequence analysis showed that MdPYL9 shares a high similarity with AtPYL9. Protein sequence comparison and 3D structure prediction identified several conserved motifs and residues that are important for ABA binding in MdPYL9, including the helix-grip structure and the gate and latch loops. Expression analysis showed thatMdPYL9was significantly induced by drought treatment. Overexpression ofMdPYL9conferred enhanced tolerance to drought stress in transgenic apple plants, including a higher photosynthetic rate and relative water content and lower MDA content and electrolyte leakage compared with wild-type plants. Lower accumulation of reactive oxygen species (ROS) and higher activity of antioxidant enzymes suggest thatMdPYL9overexpression could promote ROS scavenging and thus reduce oxidative damage in transgenic apple plants under drought stress. Yeast two-hybrid assays indicated that there were both ABA-dependent and ABA-independent interactions between MdPYL9 and the clade A subgroup members of the PP2C family (PP2CAs) in apple. Expression analysis identifed two PP2CA genes,MdHAI1andMdHAI2, that were highly expressed under drought treatment by not expressed under normal conditions. These results provide new insight that could be used to aid future studies examining the function of MdPYLs and the mechanism by which they regulate apple drought tolerance.