Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya 572025, China.
Engineering Research Center for the Selection and Breeding of New Tropical Crop Varieties of Ministry of Education, College of Tropical Crops, Hainan University, Haikou 570228, China.
Int J Mol Sci. 2022 Oct 5;23(19):11801. doi: 10.3390/ijms231911801.
Drought stress is considered the main obstacle restricting Huang () yield. Hainan is the southernmost distribution region of in China and experiences a drought period annually. To study the drought-stress-response mechanism of , we treated seedlings of drought-tolerant (HD1) and drought-sensitive (WH1) cultivars with PEG-6000 (PEG) to simulate drought stress and compared the physiology and transcriptome of their leaves at 0 d, 3 d and 6 d posttreatment. Under drought stress, the growth of was inhibited, the relative water content (RWC) of leaves decreased and the contents of malondialdehyde (MDA), antioxidant enzyme activities, osmotic regulatory substances and secondary metabolites increased. Compared with those of WH1, the leaf RWC, osmotic-regulation substance content (proline, soluble protein and soluble sugar) and antioxidant enzyme activity (superoxide dismutase, peroxidase and catalase) of HD1 were significantly increased, while the relative electrical conductivity and MDA content were significantly decreased. Compared with WH1, 2812, 2070 and 919, differentially expressed genes (DEGs) were detected in HD1 0 d, 3 d and 6 d posttreatment, respectively, and the number of DEGs increased with increasing treatment time. The detected DEGs are involved in the drought stress response of mainly through plant-hormone signal transduction and lignin and flavonoid biosynthesis pathways. Drought stress significantly activated the expression of several lignin and flavonoid biosynthesis genes in HD1. Moreover, total flavonoid and total polyphenol contents in HD1 were significantly increased, suggesting that the accumulation of flavonoids may be a key factor in the drought stress response of . Additionally, 191 DEGs were associated with coding transcription factors (TFs). This study provides insight into the molecular mechanism of the drought stress response of and provides a theoretical basis for the development and cultivation of new drought-resistant cultivars.
干旱胁迫被认为是限制 （Huang）产量的主要障碍。海南是中国 （）分布的最南端地区，每年都会经历干旱期。为了研究 的干旱胁迫响应机制，我们用聚乙二醇-6000（PEG）处理耐旱（HD1）和干旱敏感（WH1）品种的幼苗来模拟干旱胁迫，并比较了处理后 0、3 和 6 天叶片的生理和转录组。在干旱胁迫下， 的生长受到抑制，叶片相对含水量（RWC）下降，丙二醛（MDA）、抗氧化酶活性、渗透调节物质和次生代谢物含量增加。与 WH1 相比，HD1 的叶片 RWC、渗透调节物质含量（脯氨酸、可溶性蛋白和可溶性糖）和抗氧化酶活性（超氧化物歧化酶、过氧化物酶和过氧化氢酶）显著增加，而相对电导率和 MDA 含量显著降低。与 WH1 相比，在 HD1 处理后 0、3 和 6 天分别检测到 2812、2070 和 919 个差异表达基因（DEGs），且随着处理时间的增加，DEGs 的数量增加。检测到的 DEGs 主要通过植物激素信号转导和木质素和类黄酮生物合成途径参与 的干旱胁迫响应。干旱胁迫显著激活了 HD1 中几个木质素和类黄酮生物合成基因的表达。此外，HD1 中总黄酮和总多酚含量显著增加，表明黄酮类化合物的积累可能是 的干旱胁迫响应的关键因素。此外，有 191 个 DEGs 与编码转录因子（TFs）有关。本研究为 干旱胁迫响应的分子机制提供了见解，并为新的抗旱品种的开发和培育提供了理论依据。
