State Key Laboratory of Crop Biology, National Research Center for Apple Engineering and Technology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, China; Shandong Institute of Pomology, Tai'an, Shandong 271000, China.
J Plant Physiol. 2013 Apr 15;170(6):601-9. doi: 10.1016/j.jplph.2012.12.014. Epub 2013 Feb 9.
Vacuole H(+)-ATPases (VHAs) are plant proton pumps, which play a crucial role in plant growth and stress tolerance. In the present study, we demonstrated that the apple vacuolar H(+)-ATPase subunit A (MdVHA-A) is highly conserved with subunit A of VHA (VHA-A) proteins from other plant species. MdVHA-A was expressed in vegetative and reproductive organs. In apple in vitro shoot cultures, expression was induced by polyethylene glycol (PEG)-mediated osmotic stress. We further verified that over-expression of MdVHA-A conferred transgenic tobacco seedlings with enhanced vacuole H+-ATPase (VHA) activity and improved drought tolerance. The enhanced PEG-mimic drought response of transgenic tobacco seedlings was related to an extended lateral root system (dependent on auxin translocation) and more efficient osmotic adjustment. Our results indicate that MdVHA-A is a candidate gene for improving drought tolerance in plants.
液泡 H(+)-ATP 酶 (VHAs) 是植物质子泵，在植物生长和应激耐受中发挥着关键作用。在本研究中，我们证明了苹果液泡 H(+)-ATP 酶亚基 A (MdVHA-A) 与其他植物物种的 VHA-A 蛋白高度保守。MdVHA-A 在营养和生殖器官中表达。在苹果体外芽培养中，通过聚乙二醇 (PEG) 介导的渗透胁迫诱导表达。我们进一步证实，过表达 MdVHA-A 可使转基因烟草幼苗中的液泡 H+-ATP 酶 (VHA) 活性增强，耐旱性提高。转基因烟草幼苗对 PEG 模拟干旱的响应增强与侧根系统的延长（依赖于生长素的转运）和更有效的渗透调节有关。我们的结果表明，MdVHA-A 是提高植物耐旱性的候选基因。
