Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, 318000, China.
College of Life Science and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China.
BMC Genomics. 2022 Sep 26;23(1):670. doi: 10.1186/s12864-022-08889-8.
Abiotic stresses have increasingly serious effects on the growth and yield of crops. Cold stress, in particular, is an increasing problem. In this study, Fragaria daltoniana and F. vesca were determined to be cold-resistant and cold-sensitive species, respectively. Integrated transcriptomics and metabolomics methods were used to analyze the regulatory mechanism of abscisic acid (ABA) in F. daltoniana and F. vesca in their response to low temperature stress.
F. daltoniana and F. vesca increased their ABA content under low temperature stress by upregulating the expression of the ABA biosynthetic pathway gene NCED and downregulating the expression of the ABA degradative gene CYP707A. Both types of regulation increased the accumulation of glucose and fructose, resulting in a reduction of damage under low temperature stress. Twelve transcription factors were found to be involved in the ABA regulatory pathway. The strong cold tolerance of F. daltoniana could be owing to its higher levels of ABA that accumulated compared with those in F. vesca under low temperature stress. In addition, the gene ABF2, which is related to the transduction of glucose signaling, was significantly upregulated in the leaves of F. daltoniana, while it was downregulated in the leaves of F. vesca under low temperature stress. This could contribute to the higher levels of glucose signal transduction in F. daltoniana. Thus, this could explain the higher peroxidase activity and lower damage to cell membranes in the leaves of F. daltoniana compared with F. vesca under low temperature stress, which endows the former with stronger cold tolerance.
Under low temperature stress, the differences in the accumulation of ABA and the expression trends of ABF2 and ABF4 in different species of wild strawberries may be the primary reason for their differences in cold tolerance. Our results provide an important empirical reference and technical support for breeding resistant cultivated strawberry plants.
非生物胁迫对作物的生长和产量有越来越严重的影响。特别是冷胁迫是一个日益严重的问题。本研究确定了弗吉尼亚草莓和智利草莓分别为耐寒和热敏品种。采用整合转录组学和代谢组学方法，分析了草莓响应低温胁迫时脱落酸（ABA）的调控机制。
草莓在低温胁迫下通过上调 ABA 生物合成途径基因 NCED 的表达和下调 ABA 降解基因 CYP707A 的表达来增加 ABA 含量。这两种调控方式都增加了葡萄糖和果糖的积累，从而降低了低温胁迫下的损伤。发现有 12 个转录因子参与 ABA 调控途径。弗吉尼亚草莓具有较强的耐寒性，可能是因为在低温胁迫下其积累的 ABA 水平高于智利草莓。此外，与葡萄糖信号转导有关的基因 ABF2 在弗吉尼亚草莓的叶片中显著上调，而在低温胁迫下智利草莓的叶片中下调。这可能有助于提高弗吉尼亚草莓中葡萄糖信号转导的水平。因此，这可以解释为什么弗吉尼亚草莓在低温胁迫下叶片的过氧化物酶活性较高，细胞膜损伤较小，从而具有更强的耐寒性。
在低温胁迫下，不同野生草莓物种中 ABA 的积累差异以及 ABF2 和 ABF4 的表达趋势的差异可能是其耐寒性差异的主要原因。我们的研究结果为培育抗寒栽培草莓植物提供了重要的经验参考和技术支持。
