Research Center of Crop Stresses Resistance Technologies/ MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River, Yangtze University, Jingzhou, 434025, China.
Mol Biol Rep. 2024 Jun 13;51(1):731. doi: 10.1007/s11033-024-09651-x.
Chitinase (Chi) is a pathogenesis-related protein, also reported to play an important role in plant responses to abiotic stress. However, its role in response to abiotic stress in barley is still unclear.
In this study, a total of 61 Chi gene family members were identified from the whole genome of wild barley EC_S1. Phylogenetic analysis suggested that these family genes were divided into five groups. Among these genes, four pairs of collinearity genes were discovered. Besides, abundant cis-regulatory elements, including drought response element and abscisic acid response element were identified in the promoter regions of HvChi gene family members. The expression profiles revealed that most HvChi family members were significantly up-regulated under drought stress, which was also validated by RT-qPCR measurements. To further explore the role of Chi under drought stress, HvChi22 was overexpressed in Arabidopsis. Compared to wild-type plants, overexpression of HvChi22 enhanced drought tolerance by increasing the activity of oxidative protective enzymes, which caused less MDA accumulation.
Our study improved the understanding of the Chi gene family under drought stress in barley, and provided a theoretical basis for crop improvement strategies to address the challenges posed by changing environmental conditions.
几丁质酶（Chi）是一种与发病机制相关的蛋白质，据报道，它在植物应对非生物胁迫中也发挥着重要作用。然而，其在大麦应对非生物胁迫中的作用尚不清楚。
本研究从野生大麦 EC_S1 的全基因组中鉴定出了 61 个 Chi 基因家族成员。系统发育分析表明，这些家族基因分为五个组。在这些基因中，发现了四对共线性基因。此外，在 HvChi 基因家族成员的启动子区域中还鉴定到了丰富的顺式调控元件，包括干旱响应元件和脱落酸响应元件。表达谱显示，大多数 HvChi 家族成员在干旱胁迫下显著上调，这也通过 RT-qPCR 测量得到了验证。为了进一步探究 Chi 在干旱胁迫下的作用，在拟南芥中过表达了 HvChi22。与野生型植物相比，HvChi22 的过表达通过增加氧化保护酶的活性增强了耐旱性，从而导致 MDA 积累减少。
本研究提高了对大麦在干旱胁迫下 Chi 基因家族的理解，为应对不断变化的环境条件所带来的挑战的作物改良策略提供了理论依据。
