School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, China.
Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, USA.
Int J Mol Sci. 2022 Mar 21;23(6):3380. doi: 10.3390/ijms23063380.
Cold stress is one of the abiotic stress conditions that severely limit plant growth and development and productivity. Triacylglycerol lipases are important metabolic enzymes for the catabolism of triacylglycerols and, therefore, play important roles in cellular activities including seed germination and early seedling establishment. However, whether they play a role in cold stress responses remains unknown. In this study, we characterized two Arabidopsis triacylglycerol lipases, MPL1 and LIP1 and defined their role in cold stress. The expression of and is reduced by cold stress, suggesting that they may be negative factors related to cold stress. Indeed, we found that loss-of-function of and resulted in increased cold tolerance and that the double mutant displayed an additive effect on cold tolerance. We performed RNA-seq analysis to reveal the global effect of the and mutations on gene expression under cold stress. The mutation had a small effect on gene expression under both under control and cold stress conditions whereas the mutation caused a much stronger effect on gene expression under control and cold stress conditions. The double mutant had a moderate effect on gene expression under control and cold stress conditions. Together, our results indicate that MPL1 and LIP1 triacylglycerol lipases are negative regulators of cold tolerance without any side effects on growth in Arabidopsis and that they might be ideal candidates for breeding cold-tolerant crops through genome editing technology.
冷胁迫是严重限制植物生长、发育和生产力的非生物胁迫条件之一。三酰基甘油脂肪酶是三酰基甘油分解代谢的重要代谢酶，因此在包括种子萌发和早期幼苗建立在内的细胞活动中发挥重要作用。然而，它们是否在冷胁迫反应中发挥作用尚不清楚。在这项研究中，我们对拟南芥的两种三酰基甘油脂肪酶 MPL1 和 LIP1 进行了表征，并定义了它们在冷胁迫中的作用。和 的表达受冷胁迫下调，表明它们可能是与冷胁迫相关的负调控因子。事实上，我们发现和 的功能丧失导致对冷胁迫的耐受性增加，并且双突变体在冷耐受性上表现出累加效应。我们进行了 RNA-seq 分析，以揭示和 的突变对冷胁迫下基因表达的全局影响。在对照和冷胁迫条件下，突变对基因表达的影响较小，而突变在对照和冷胁迫条件下对基因表达的影响更强。双突变体在对照和冷胁迫条件下对基因表达的影响适中。总之，我们的结果表明，MPL1 和 LIP1 三酰基甘油脂肪酶是冷耐受性的负调控因子，对拟南芥的生长没有任何副作用，它们可能是通过基因组编辑技术培育耐寒作物的理想候选基因。
