Shijiazhuang Academy of Agricultural and Forestry Sciences, 479 Shenglibei Street, Shijiazhuang, 050041, Hebei, China.
National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
BMC Plant Biol. 2021 Aug 12;21(1):369. doi: 10.1186/s12870-021-03157-5.
Low temperature severely limits the growth, yield, and geographic distributions of soybean. Soybean plants respond to cold stress by reprogramming the expression of a series of cold-responsive genes. However, the intrinsic mechanism underlying cold-stress tolerance in soybean remains unclear. A. thaliana tolerant to chilling and freezing 1 (AtTCF1) is a regulator of chromosome condensation 1 (RCC1) family protein and regulates freezing tolerance through an independent C-repeat binding transcription factor (CBF) signaling pathway.
In this study, we identified a homologous gene of AtTCF1 in soybean (named GmTCF1a), which mediates plant tolerance to low temperature. Like AtTCF1, GmTCF1a contains five RCC1 domains and is located in the nucleus. GmTCF1a is strongly and specifically induced by cold stress. Interestingly, ectopic overexpression of GmTCF1a in Arabidopsis greatly increased plant survival rate and decreased electrolyte leakage under freezing stress. A cold-responsive gene, COR15a, was highly induced in the GmTCF1a-overexpressing transgenic lines.
GmTCF1a responded specifically to cold stress, and ectopic expression of GmTCF1a enhanced cold tolerance and upregulated COR15a levels. These results indicate that GmTCF1a positively regulates cold tolerance in soybean and may provide novel insights into genetic improvement of cold tolerance in crops.
低温严重限制了大豆的生长、产量和地理分布。大豆植物通过重新编程一系列冷响应基因来应对冷胁迫。然而，大豆耐冷性的内在机制仍不清楚。拟南芥耐冷和耐冻 1（AtTCF1）是染色体凝聚 1（RCC1）家族蛋白的调节剂，通过独立的 C-重复结合转录因子（CBF）信号通路调节耐冻性。
在本研究中，我们在大豆中鉴定到一个与 AtTCF1 同源的基因（命名为 GmTCF1a），它介导植物对低温的耐受性。与 AtTCF1 一样，GmTCF1a 含有五个 RCC1 结构域，位于细胞核内。GmTCF1a 强烈且特异性地被低温诱导。有趣的是，在拟南芥中异位过表达 GmTCF1a 大大提高了植物在冷冻胁迫下的存活率并降低了电解质渗漏。冷响应基因 COR15a 在 GmTCF1a 过表达转基因株系中高度诱导。
GmTCF1a 对冷胁迫有特异性反应，异位表达 GmTCF1a 增强了大豆的耐寒性并上调了 COR15a 的水平。这些结果表明，GmTCF1a 正向调节大豆的耐寒性，可能为作物耐寒性的遗传改良提供新的思路。
