背景回顾：Salt and drought stresses are major factors limiting soybean (Glycine max [L.] Merr.) growth and development; thus, improving soybean stress tolerance is critical. 

结果1-表达模式：In this study, both salt stress and drought stress induced mRNA levels of CONSTANS-like 1a (GmCOL1a) and stabilized the GmCOL1a protein. 

结果2-过表达和敲除表型：Transgenic 35S:GmCOL1a soybean plants exhibited enhanced salt and drought tolerance, with higher relative water content in leaves, greater proline content, lower malondialdehyde (MDA) content, and less reactive oxygen species (ROS) production compared with wild-type plants; the GmCOL1a knockout co-9 mutant showed opposite phenotypes. 

结果3-盐胁迫抗性：In addition, GmCOL1apromoted the expression of genes related to salt tolerance, effectively reducing the Na+/K+ ratio in soybean plants, especially in stems and leaves of 35S:GmCOL1a soybean. 

结果4-盐和干旱胁迫抗性：Chromatin immunoprecipitation sequencing (ChIP-seq) analysis identified two potential direct targets of GmCOL1a, late embryogenesis abundant (GmLEA) and Δ1-pyrroline-5-carboxylate synthetase (GmP5CS) genes, which were verified by chromatin immunoprecipitation quantitative polymerase chain reaction (ChIP-qPCR), electrophoretic mobility shift assay (EMSA), and transient transcriptional activation assays. GmCOL1a bound directly to the Myc(bHLH)-binding and Che-binding motifs of GmLEA and GmP5CS promoters to stimulate mRNA expression. Analysis of transgenic hairy-root GmP5CS:GmP5CS soybean plants in wild-type, co-9, and 35S:GmCOL1a backgrounds further revealed that GmCOL1a enhances salt and drought tolerance by promoting GmP5CS protein accumulation in transgenic soybean hairy roots. 

结论：We therefore demonstrate that GmCOL1a plays an important role in tolerance to abiotic stress in soybean.

Proposed model depicting the function of GmCOL1a in the regulation of salt and drought stress tolerance.

盐和干旱胁迫是限制大豆生长和发育的主要因子；因此，改良大豆的胁迫抗性至关重要。在本文中，盐胁迫和干旱胁迫都会诱导大豆GmCOL1a的表达水平，并且稳定GmCOL1a蛋白。35S:GmCOL1a株系的大豆表现出盐和干旱耐受性增强的表型，具体表现为相比于野生型具有更高的叶片含水量、更高的脯氨酸含量、更低的MDA含量以及更少的ROS生成；而GmCOL1a敲除突变体co-9则表现出完全相反的表型。另外，GmCOL1a能够促进与盐胁迫耐受性相关基因的表达，有效降低大豆植株中的纳/钾离子比率，尤其是过表达植株的茎干和叶片中。ChlP-seq分析鉴定到了两个GmCOL1a的潜在靶标，分别是GmLEA和GmP5CS基因。作者进一步通过ChIP-qPCR、 EMSA和瞬时转录激活实验验证了GmCOL1a对GmLEA和GmP5CS的调控作用。GmCOL1a能够直接结合到GmLEA和GmP5CS启动子区域的bHLH和Che结合基序上，刺激这两个基因的转录。进一步通过在野生型、co-9突变体和35S:GmCOL1a过表达株系背景下定量毛状根中GmP5CS:GmP5CS的表达，发现GmCOL1a通过促进GmP5CS在转基因大豆毛状根中的蛋白积累，从而提升其干旱抗性。本文的研究结果揭示了GmCOL1a在大豆非生物胁迫抗性中的重要作用。

** 赵 琳 **