College of Life Sciences, Northeast Agricultural University, Harbin 150030, China.
Key Laboratory of Soybean Biology of Chinese Education Ministry, Harbin 150030, China.
Int J Mol Sci. 2022 May 12;23(10):5407. doi: 10.3390/ijms23105407.
Wild soybean, the progenitor and close relative of cultivated soybean, has an excellent environmental adaptation ability and abundant resistance genes. Expansins, as a class of cell wall relaxation proteins, have important functions in regulating plant growth and stress resistance. In the present study, we identified a total of 75 members of the expansin family on the basis of recent genomic data published for wild soybean. The predicted results of promoter elements structure showed that wild soybean expansin may be associated with plant hormones, stress responses, and growth. Basal transcriptome data of vegetative organs suggest that the transcription of expansin members has some organ specificity. Meanwhile, the transcripts of some members had strong responses to salt, low temperature and drought stress. We screened and obtained an expansin gene, , which is transcribed specifically in roots and actively responds to salt stress. The results of transient transfection showed that this protein was localized in the cell wall of onion epidermal cells. We initially analyzed the function of by a soybean hairy root transformation assay and found that overexpression of significantly increased the number of hairy roots, root length, root weight, and the tolerance to salt stress. This research provides a foundation for subsequent studies of expansins in wild soybean.
野生大豆是栽培大豆的祖先和近缘种，具有出色的环境适应能力和丰富的抗性基因。扩展蛋白作为一类细胞壁松弛蛋白，在调节植物生长和抗逆性方面具有重要功能。本研究基于近期发表的野生大豆基因组数据，共鉴定到 75 个扩展蛋白家族成员。启动子元件结构的预测结果表明，野生大豆扩展蛋白可能与植物激素、应激反应和生长有关。营养器官的基础转录组数据表明，扩展蛋白成员的转录具有一定的器官特异性。同时，一些成员的转录本对盐、低温和干旱胁迫有强烈的响应。我们筛选并获得了一个扩展蛋白基因 ，该基因特异性转录于根中，并对盐胁迫有积极响应。瞬时转染结果表明，该蛋白定位于洋葱表皮细胞的细胞壁中。我们初步通过大豆毛状根转化实验分析了 的功能，发现过表达 显著增加了毛状根的数量、根长、根重以及对盐胁迫的耐受性。这项研究为野生大豆中扩展蛋白的后续研究提供了基础。
