Zhang Xiuxiu, Xia Xiuzhi, Sun Yu, Wang Runze, Liang Kemeng, Wang Yarong, Ren Lifei, Wang Qin
State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, People's Republic of China.
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, People's Republic of China.
Plant Cell Rep. 2024 Dec 13;44(1):4. doi: 10.1007/s00299-024-03395-5.
All ten dehydrin genes from three Medicago species are responsive to different kinds of abiotic stress, and CAS31 confers transgenic plants salt tolerance by down-regulating HKT1 expression. Dehydrins are protective proteins playing crucial roles in the tolerance of plants to abiotic stresses. However, a full-scale and systemic analysis of total dehydrin genes in Medicago at the genome level is still lacking. In this study, we identified ten dehydrin genes from three Medicago species (M. truncatula, M. ruthenica, and M. sativa), categorizing the coding proteins into four types. Genome collinearity analysis among the three Medicago species revealed six orthologous gene pairs. Promoter regions of dehydrin genes contained various phytohormone- and stress-related cis-elements, and transcriptome analysis showed up-regulation of all ten dehydrin genes under different stress conditions. Transformation of dehydrin gene CAS31 increased the tolerance of transgenic seedlings compared with wild-type seedlings under salt stress. Our study demonstrated that transgenic seedlings maintained the more chlorophyll, accumulated more proline and less hydrogen peroxide and malondialdehyde than wild-type seedlings under salt stress. Further study revealed that CAS31 reduced Na accumulation by down-regulating HKT1 expression under salt stress. These findings enhance our understanding of the dehydrin gene family in three Medicago species and provide insights into their mechanisms of tolerance.
来自三种苜蓿属植物的所有十个脱水素基因对不同类型的非生物胁迫均有响应，且CAS31通过下调HKT1表达赋予转基因植物耐盐性。脱水素是保护性蛋白，在植物对非生物胁迫的耐受性中发挥关键作用。然而，苜蓿属植物中脱水素基因在基因组水平上的全面系统分析仍然缺乏。在本研究中，我们从三种苜蓿属植物（蒺藜苜蓿、花苜蓿和紫花苜蓿）中鉴定出十个脱水素基因，将编码蛋白分为四种类型。三种苜蓿属植物之间的基因组共线性分析揭示了六对直系同源基因。脱水素基因的启动子区域包含各种与植物激素和胁迫相关的顺式元件，转录组分析表明所有十个脱水素基因在不同胁迫条件下均上调。与野生型幼苗相比，脱水素基因CAS31转化的转基因幼苗在盐胁迫下的耐受性增强。我们的研究表明，在盐胁迫下，转基因幼苗比野生型幼苗保留更多叶绿素，积累更多脯氨酸，过氧化氢和丙二醛含量更低。进一步研究表明，在盐胁迫下，CAS31通过下调HKT1表达减少了钠的积累。这些发现加深了我们对三种苜蓿属植物中脱水素基因家族的理解，并为其耐受机制提供了见解。
