State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China.
Plant Biotechnol J. 2020 Mar;18(3):791-804. doi: 10.1111/pbi.13247. Epub 2019 Sep 17.
As one of the largest gene families in plants, the cytochrome P450 monooxygenase genes (CYPs) are involved in diverse biological processes including biotic and abiotic stress response. Moreover, P450 genes are prone to expanding due to gene tandem duplication during evolution, resulting in generations of novel alleles with the neo-function or enhanced function. Here, the bread wheat (Triticum aestivum) gene TaCYP81D5 was found to lie within a cluster of five tandemly arranged CYP81D genes, although only a single such gene (BdCYP81D1) was present in the equivalent genomic region of the wheat relative Brachypodium distachyon. The imposition of salinity stress could up-regulate TaCYP81D5, but the effect was abolished in plants treated with an inhibitor of reactive oxygen species synthesis. In SR3, a wheat cultivar with an elevated ROS content, the higher expression and the rapider response to salinity of TaCYP81D5 were related to the chromatin modification. Constitutively expressing TaCYP81D5 enhanced the salinity tolerance both at seedling and reproductive stages of wheat via accelerating ROS scavenging. Moreover, an important component of ROS signal transduction, Zat12, was proven crucial in this process. Though knockout of solely TaCYP81D5 showed no effect on salinity tolerance, knockdown of BdCYP81D1 or all TaCYP81D members in the cluster caused the sensitivity to salt stress. Our results provide the direct evidence that TaCYP81D5 confers salinity tolerance in bread wheat and this gene is prospective for crop improvement.
作为植物中最大的基因家族之一，细胞色素 P450 单加氧酶基因（CYPs）参与多种生物过程，包括生物和非生物胁迫反应。此外，由于进化过程中基因串联重复，P450 基因易于扩展，导致产生具有新功能或增强功能的新一代新等位基因。在这里，发现小麦（Triticum aestivum）基因 TaCYP81D5 位于五个串联排列的 CYP81D 基因簇内，尽管在小麦相对 Brachypodium distachyon 的等效基因组区域中仅存在单个此类基因（BdCYP81D1）。盐胁迫会上调 TaCYP81D5，但在活性氧合成抑制剂处理的植物中，这种作用被消除。在 SR3 中，一种 ROS 含量升高的小麦品种，TaCYP81D5 的较高表达和对盐胁迫的更快响应与染色质修饰有关。通过加速 ROS 清除，组成型表达 TaCYP81D5 增强了小麦幼苗期和生殖期的耐盐性。此外，ROS 信号转导的一个重要组成部分，Zat12，被证明在这个过程中是至关重要的。尽管仅敲除 TaCYP81D5 对盐度耐受性没有影响，但敲低 BdCYP81D1 或该簇中的所有 TaCYP81D 成员会导致对盐胁迫的敏感性。我们的结果提供了直接证据，证明 TaCYP81D5 赋予面包小麦耐盐性，并且该基因有望用于作物改良。
