Abstract:
The occurrence of whole-genome duplication or polyploidy may promote plant adaptability to harsh environments. Here, we clarify the evolutionary relationship of eight GhCIPK6 homologous genes in upland cotton (Gossypium hirsutum). Gene expression and interaction analyses indicate that GhCIPK6 homologous genes show significant functional changes after polyploidy. Among these, GhCIPK6D1 and GhCIPK6D3 are significantly up-regulated by drought stress. Functional studies reveal that high GhCIPK6D1 expression promotes cotton drought sensitivity, while GhCIPK6D3 expression promotes drought tolerance, indicating clear functional differentiation. Genetic and biochemical analyses confirm the synergistic negative and positive regulation of cotton drought resistance through GhCBL1A1-GhCIPK6D1 and GhCBL2A1-GhCIPK6D3, respectively, to regulate stomatal movement by controlling the directional flow of K+ in guard cells. These results reveal differentiated roles of GhCIPK6 homologous genes in response to drought stress in upland cotton following polyploidy. The work provides a different perspective for exploring the functionalization and subfunctionalization of duplicated genes in response to polyploidization.
摘要:
全基因组复制或多倍体的发生可能促进植物对恶劣环境的适应性。这里,我们阐明了陆地棉(Gossypiumhirsutum)中八个GhCIPK6同源基因的进化关系。基因表达和相互作用分析表明,GhCIPK6同源基因在多倍体后显示出明显的功能变化。其中,GhCIPK6D1和GhCIPK6D3受干旱胁迫显著上调。功能研究表明高GhCIPK6D1表达促进棉花干旱敏感性,而GhCIPK6D3表达促进耐旱性,表明功能分化明显。遗传和生化分析分别证实了GhCBL1A1-GhCIPK6D1和GhCBL2A1-GhCIPK6D3对棉花抗旱性的协同负调节和正调节,通过控制K+在保卫细胞中的定向流动来调节气孔运动。这些结果揭示了GhCIPK6同源基因在多倍体后响应干旱胁迫中的分化作用。这项工作为探索重复基因响应多倍体化的功能化和亚功能化提供了不同的视角。