College of Agronomy and Biotechnology, Southwest University, Beibei, Chongqing, 400715, China.
Academy of Agricultural Science, Southwest University, Beibei, Chongqing, 400715, China.
Nat Commun. 2024 Mar 7;15(1):2082. doi: 10.1038/s41467-024-46271-2.
Rapeseed (Brassica napus) is one of the important oil crops worldwide. Its production is often threatened by drought stress. Here, we identify a transcription factor (BnaA9.NF-YA7) that negatively regulates drought tolerance through genome-wide association study in B. napus. The presence of two SNPs within a CCAAT cis element leads to downregulation of BnaA9.NF-YA7 expression. In addition, the M63I (G-to-C) substitution in the transactivation domain can activate low level expression of BnaA4.DOR, which is an inhibitory factor of ABA-induced stomatal closure. Furthermore, we determine that Bna.ABF3/4s directly regulate the expression of BnaA9.NF-YA7, and BnaA9.NF-YA7 indirectly suppresses the expression of Bna.ABF3/4s by regulation of Bna.ASHH4s. Our findings uncover that BnaA9.NF-YA7 serves as a supplementary role for ABA signal balance under drought stress conditions, and provide a potential molecular target to breed drought-tolerant B. napus cultivars.
油菜（甘蓝型油菜）是世界上重要的油料作物之一。其生产常受到干旱胁迫的威胁。在这里，我们通过全基因组关联研究在甘蓝型油菜中鉴定出一个转录因子（BnaA9.NF-YA7），它通过负调控来提高油菜的耐旱性。CCAAT 顺式元件内两个 SNP 的存在导致 BnaA9.NF-YA7 表达下调。此外，在转录激活域中的 M63I（G 到 C）取代可以激活 BnaA4.DOR 的低水平表达，BnaA4.DOR 是 ABA 诱导气孔关闭的抑制因子。此外，我们确定 Bna.ABF3/4s 直接调控 BnaA9.NF-YA7 的表达，而 BnaA9.NF-YA7 通过调控 Bna.ASHH4s 间接抑制 Bna.ABF3/4s 的表达。我们的研究结果揭示了 BnaA9.NF-YA7 在干旱胁迫条件下作为 ABA 信号平衡的补充作用，并为培育耐旱性油菜品种提供了一个潜在的分子靶标。
