Tropical Crops Genetic Resources Research Institute, CATAS, Danzhou Hainan, China.
PLoS One. 2020 May 29;15(5):e0233130. doi: 10.1371/journal.pone.0233130. eCollection 2020.
Low temperature is one of the abiotic factors limiting germination, growth and distribution of the plant in current plant-products industry, especially for the tropical vegetables in non-tropical area or other fields under cold temperature. Screening the plant with ability against cold temperature captured worldwide attention and exerted great importance. In our previous work, the anti-cold specie of Momordica Charantia L. seedlings was screened out. Yet, the molecular and physiological mechanisms underlying this adaptive process still remain unknown. This study was aimed to investigate adaption mechanism of anti-cold species of Momordica Charantia L. seedlings in genetical and metabolomics levels. Two species, cold-susceptible group (Y17) and cold-resistant group (Y54), were evaluated containing the indexes of malondialdehyde (MDA), hydrogen peroxide (H2O2), proline content, activities of antioxidant enzymes, metabolites changes and genes differentiation in plant tissues after cold treatment. It found that low temperature stress resulted in increased accumulation of MDA, H2O2 and proline content in two species, but less expressions in cold-resistant species Y54. As compared to Y17, cold-resistant species Y54 presented significantly enhanced antioxidant enzyme activities of POD (peroxidase), CAT (cataalase) and SOD (superoxide dismutase). Meanwhile, higher expressed genes encoded antioxidant enzymes and transcription factors when exposure to the low temperature were found in cold-resistant species Y54, and core genes were explored by Q-PCR validation, including McSOD1, McPDC1 and McCHS1. Moreover, plant metabolites containing amino acid, sugar, fatty acid and organic acid in Y54 were higher than Y17, indicating their important roles in cold acclimation. Meanwhile, initial metabolites, including amimo acids, polypeptides, sugars, organic acids and nucleobases, were apparently increased in cold resistant species Y54 than cold susceptible species Y17. Our results demonstrated that the Momordica Charantia L. seedlings achieved cold tolerance might be went through mobilization of antioxidant systems, adjustment of the transcription factors and accumulation of osmoregulation substance. This work presented meaning information for revealing the anti-cold mechanism of the Momordica Charantia L. seedlings and newsight for further screening of anti-cold species in other plant.
低温是限制植物在当前植物产品产业中发芽、生长和分布的非生物因素之一，尤其是在非热带地区的热带蔬菜或其他低温领域。筛选具有抗寒能力的植物引起了全球关注，并受到了极大的重视。在我们之前的工作中，已经筛选出了苦瓜的抗寒种。然而，这种适应过程的分子和生理机制仍然未知。本研究旨在从遗传和代谢组学水平上研究苦瓜抗寒种幼苗的适应机制。评估了两个品种，即易感组（Y17）和抗寒组（Y54），在低温处理后，评估了植物组织中丙二醛（MDA）、过氧化氢（H2O2）、脯氨酸含量、抗氧化酶活性、代谢物变化和基因分化等指标。结果表明，低温胁迫导致两个品种 MDA、H2O2和脯氨酸含量增加，但抗寒品种 Y54 的表达量较少。与 Y17 相比，抗寒品种 Y54 的 POD（过氧化物酶）、CAT（过氧化氢酶）和 SOD（超氧化物歧化酶）等抗氧化酶活性显著增强。同时，在低温胁迫下，抗寒品种 Y54 中发现了更高表达的抗氧化酶和转录因子编码基因，通过 Q-PCR 验证，核心基因包括 McSOD1、McPDC1 和 McCHS1。此外，Y54 中的氨基酸、糖、脂肪酸和有机酸等植物代谢物含量高于 Y17，表明它们在低温适应中具有重要作用。同时，在抗寒品种 Y54 中，初始代谢物，包括氨基酸、多肽、糖、有机酸和核苷，明显高于易感品种 Y17。我们的研究结果表明，苦瓜幼苗获得耐寒性可能是通过抗氧化系统的动员、转录因子的调节和渗透调节物质的积累来实现的。本研究为揭示苦瓜幼苗的抗寒机制提供了有意义的信息，并为进一步筛选其他植物的抗寒种提供了新的思路。
