Xiang Guangqing, Fan Zongbao, Lan Shuxia, Wei Dezheng, Gao Yazhe, Kang Hui, Yao Yuxin
Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, Ministry of Agriculture, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, China.
National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Dongying, China.
Plant Biotechnol J. 2025 Apr;23(4):1076-1090. doi: 10.1111/pbi.14565. Epub 2025 Jan 7.
Here, we evaluated the role of ethylene in regulating the NaHCO stress tolerance of grapevines and clarified the mechanism by which VvERF1B regulates the response to NaHCO stress. The exogenous application of ACC and VvACS3 overexpression in grapevines and grape calli revealed that ethylene increased NaHCO stress tolerance, and this was accompanied by increased plasma membrane H-ATPase (PMA) activity. The expression of VvERF1B was strongly induced by ACC, and overexpression of this gene in grapevines conferred increased NaHCO stress tolerance and enhanced PMA activity and H and oxalate secretion. Additionally, the function of VvERF1B was also verified using mutant transgenic grape calli and overexpression in Arabidopsis plants. The expression of VvPMA10 was strongly induced following the overexpression of VvERF1B in grapevine roots, and VvPMA10 was shown to regulate PMA activity, oxalate and H secretion, and NaHCO stress tolerance via its overexpression and mutation in grapevine roots, calli, and/or Arabidopsis. However, VvPMA10 was not a direct target gene of VvERF1B but was directly transactivated by VvMYC2. The function of VvMYC2 was shown to be similar to that of VvPMA10 via its overexpression and mutation in grape calli. Additional experiments revealed that the interaction of VvERF1B with VvMYC2 increased its ability to activate VvPMA10 expression and that VvMYC2 played a role in the VvERF1B-mediated pathway. Overall, the VvERF1B-VvMYC2-VvPMA pathway played a role in regulating ethylene-induced NaHCO stress tolerance in grapevines, and this process contributed to increases in PMA activity and H and oxalate secretion.
在此，我们评估了乙烯在调节葡萄对NaHCO胁迫耐受性中的作用，并阐明了VvERF1B调节对NaHCO胁迫响应的机制。在葡萄和葡萄愈伤组织中外源施加ACC以及VvACS3过表达表明，乙烯提高了对NaHCO胁迫的耐受性，同时伴随着质膜H⁺-ATP酶（PMA）活性的增加。ACC强烈诱导VvERF1B的表达，该基因在葡萄中的过表达赋予了更高的NaHCO胁迫耐受性，并增强了PMA活性以及H⁺和草酸盐的分泌。此外，还利用突变转基因葡萄愈伤组织和在拟南芥植株中的过表达验证了VvERF1B的功能。在葡萄根中过表达VvERF1B后，VvPMA10的表达强烈诱导，并且通过在葡萄根、愈伤组织和/或拟南芥中的过表达和突变表明，VvPMA10调节PMA活性、草酸盐和H⁺分泌以及对NaHCO胁迫的耐受性。然而，VvPMA10不是VvERF1B的直接靶基因，而是由VvMYC2直接反式激活。通过在葡萄愈伤组织中的过表达和突变表明，VvMYC2的功能与VvPMA10相似。进一步的实验表明，VvERF1B与VvMYC2的相互作用增强了其激活VvPMA10表达的能力，并且VvMYC2在VvERF1B介导的途径中发挥作用。总体而言，VvERF1B-VvMYC2-VvPMA途径在调节乙烯诱导的葡萄对NaHCO胁迫耐受性中发挥作用，这一过程促进了PMA活性以及H⁺和草酸盐分泌的增加。
