Institute of Cereal and Oil Crops, Hebei Academy of Agriculture and Forestry Sciences/Hebei Key Laboratory of Crop Cultivation Physiology and Green Production, Shijiazhuang, 050035, P.R. China.
State Key Laboratory of North China Crop Improvement and Regulation, Hebei Agricultural University, Baoding, 071001, P.R. China.
BMC Plant Biol. 2024 Jul 25;24(1):705. doi: 10.1186/s12870-024-05420-x.
Drought stress limits significantly the crop productivity. However, plants have evolved various strategies to cope with the drought conditions by adopting complex molecular, biochemical, and physiological mechanisms. Members of the nuclear factor Y (NF-Y) transcription factor (TF) family constitute one of the largest TF classes and are involved in plant responses to abiotic stresses.
TaNF-YB2, a NY-YB subfamily gene in T. aestivum, was characterized in this study focusing on its role in mediating plant adaptation to drought stress. Yeast two-hybrid (Y-2 H), biomolecular fluoresence complementation (BiFC), and Co-immunoprecipitation (Co-IP) assays indicated that TaNF-YB2 interacts with the NF-YA member TaNF-YA7 and NF-YC family member TaNF-YC7, which constitutes a heterotrimer TaNF-YB2/TaNF-YA7/TaNF-YC7. The TaNF-YB2 transcripts are induced in roots and aerial tissues upon drought signaling; GUS histochemical staining analysis demonstrated the roles of cis-regulatory elements ABRE and MYB situated in TaNF-YB2 promoter to contribute to target gene response to drought. Transgene analysis on TaNF-YB2 confirmed its functions in regulating drought adaptation via modulating stomata movement, osmolyte biosynthesis, and reactive oxygen species (ROS) homeostasis. TaNF-YB2 possessed the abilities in transcriptionally activating TaP5CS2, the P5CS family gene involving proline biosynthesis and TaSOD1, TaCAT5, and TaPOD5, the genes encoding antioxidant enzymes. Positive correlations were found between yield and the TaNF-YB2 transcripts in a core panel constituting 45 wheat cultivars under drought condition, in which two types of major haplotypes including TaNF-YB2-Hap1 and -Hap2 were included, with the former conferring more TaNF-YB2 transcripts and stronger plant drought tolerance.
TaNF-YB2 is transcriptional response to drought stress. It is an essential regulator in mediating plant drought adaptation by modulating the physiological processes associated with stomatal movement, osmolyte biosynthesis, and reactive oxygen species (ROS) homeostasis, depending on its role in transcriptionally regulating stress response genes. Our research deepens the understanding of plant drought stress underlying NF-Y TF family and provides gene resource in efforts for molecular breeding the drought-tolerant cultivars in T. aestivum.
干旱胁迫极大地限制了作物的生产力。然而，植物已经进化出各种策略来应对干旱条件，采用复杂的分子、生化和生理机制。核因子 Y（NF-Y）转录因子（TF）家族的成员构成了最大的 TF 家族之一，参与植物对非生物胁迫的反应。
本研究对 TaNF-YB2 进行了特征描述，TaNF-YB2 是 T. aestivum 中的 NY-YB 亚家族基因，主要关注其在介导植物适应干旱胁迫中的作用。酵母双杂交（Y-2H）、生物分子荧光互补（BiFC）和免疫共沉淀（Co-IP）实验表明，TaNF-YB2 与 NF-YA 成员 TaNF-YA7 和 NF-YC 家族成员 TaNF-YC7 相互作用，构成一个异源三聚体 TaNF-YB2/TaNF-YA7/TaNF-YC7。干旱信号诱导根和地上组织中 TaNF-YB2 转录本的诱导；GUS 组织化学染色分析表明，TaNF-YB2 启动子中位于顺式调控元件 ABRE 和 MYB 有助于靶基因对干旱的响应。TaNF-YB2 转基因分析证实了其通过调节气孔运动、渗透物质合成和活性氧（ROS）稳态来调节干旱适应的功能。TaNF-YB2 具有转录激活 TaP5CS2 的能力，TaP5CS2 是涉及脯氨酸合成的 P5CS 家族基因，以及 TaSOD1、TaCAT5 和 TaPOD5，它们分别编码抗氧化酶。在一个由 45 个小麦品种组成的核心群体中，发现产量与干旱条件下的 TaNF-YB2 转录本之间存在正相关，其中包括两种主要单倍型 TaNF-YB2-Hap1 和 -Hap2，前者赋予更多的 TaNF-YB2 转录本和更强的植物耐旱性。
TaNF-YB2 是对干旱胁迫的转录响应。它是一种重要的调节剂，通过调节与气孔运动、渗透物质合成和活性氧（ROS）稳态相关的生理过程，来介导植物对干旱的适应，这取决于其在转录调控应激响应基因中的作用。我们的研究加深了对 NF-Y TF 家族中植物干旱胁迫的理解，并为小麦分子育种耐旱品种提供了基因资源。
