Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory/ Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
Nat Commun. 2024 May 27;15(1):4493. doi: 10.1038/s41467-024-48760-w.
Abscisic acid (ABA) plays a crucial role in promoting plant stress resistance and seed dormancy. However, how ABA regulates rice quality remains unclear. This study identifies a key transcription factor SLR1-like2 (SLRL2), which mediates the ABA-regulated amylose content (AC) of rice. Mechanistically, SLRL2 interacts with NF-YB1 to co-regulate Wx, a determinant of AC and rice quality. In contrast to SLR1, SLRL2 is ABA inducible but insensitive to GA. In addition, SLRL2 exhibits DNA-binding activity and directly regulates the expression of Wx, bHLH144 and MFT2. SLRL2 competes with NF-YC12 for interaction with NF-YB1. NF-YB1 also directly represses SLRL2 transcription. Genetic validation supports that SLRL2 functions downstream of NF-YB1 and bHLH144 in regulating rice AC. Thus, an NF-YB1-SLRL2-bHLH144 regulatory module is successfully revealed. Furthermore, SLRL2 regulates rice dormancy by modulating the expression of MFT2. In conclusion, this study revealed an ABA-responsive regulatory cascade that functions in both rice quality and seed dormancy.
脱落酸(ABA)在促进植物抗逆性和种子休眠方面起着至关重要的作用。然而,ABA 如何调节水稻品质尚不清楚。本研究鉴定了一个关键的转录因子 SLR1-like2(SLRL2),它介导了 ABA 调节的水稻直链淀粉含量(AC)。在机制上,SLRL2 与 NF-YB1 相互作用,共同调控 AC 和稻米品质的决定因子 Wx。与 SLR1 不同,SLRL2 受 ABA 诱导但对 GA 不敏感。此外,SLRL2 表现出 DNA 结合活性,并直接调控 Wx、bHLH144 和 MFT2 的表达。SLRL2 与 NF-YC12 竞争与 NF-YB1 的相互作用。NF-YB1 也直接抑制 SLRL2 的转录。遗传验证支持 SLRL2 在调节水稻 AC 中作为 NF-YB1 和 bHLH144 的下游发挥作用。因此,成功揭示了一个 NF-YB1-SLRL2-bHLH144 调控模块。此外,SLRL2 通过调节 MFT2 的表达来调节水稻休眠。总之,本研究揭示了一个 ABA 响应的调控级联,在水稻品质和种子休眠中都起作用。