《植物生理学报》 2017, 53(6): 1007-1014

过量表达霸王ZxNHX和ZxVP1-1基因增强甜菜对渗透胁迫的耐受性

伍国强^1,*, 冯瑞军¹, 魏金魁¹, 王锁民², 王春梅³

¹兰州理工大学生命科学与工程学院, 兰州730050; ²兰州大学草地农业科技学院, 草地农业生态系统国家重点实验室, 兰州730020; ³中国农业科学院兰州畜牧与兽药研究所, 兰州730050

通信作者：伍国强；E-mail: wugq08@126.com

摘　要：

以过量表达霸王液泡膜Na⁺/H⁺逆向转运蛋白ZxNHX和H⁺-PPase ZxVP1-1基因的甜菜植株和野生型植株为材料, 探究渗透胁迫下其生长、Na⁺、K⁺、Ca²⁺、脯氨酸和可溶性糖含量的变化, 分析转基因植株对渗透胁迫的耐受性。结果表明, 渗透胁迫下野生型植株的生长受到抑制, 叶片发黄和萎蔫; 而转基因植株仍能维持正常生长。渗透胁迫下转基因植株的鲜重和组织含水量较野生型植株高41%和38%, 地上部Na⁺浓度是野生型植株的1.2~1.5倍, 其脯氨酸浓度较野生型植株增加40%~60%。野生型植株地上部和根中K⁺浓度显著性降低, 而转基因植株叶片中K⁺分配比例增加20%。与野生型植株相比, 转基因植株叶片、叶柄中的果糖和葡萄糖含量高35%~100%, 贮藏根中蔗糖含量高6%~16%。因此, 过量表达ZxNHX和ZxVP1-1基因能够增强甜菜离子区域化能力, 使其地上部积累更多的Na⁺、Ca²⁺、脯氨酸、果糖和葡萄糖, 贮藏根中积累更多蔗糖, 从而增强甜菜植株对渗透胁迫的耐受性。

关键词：甜菜; 抗旱性; 可溶性糖; ZxNHX; ZxVP1-1

收稿：2017-05-12  

资助：国家自然科学基金(31460101和31260294)、兰州市人才创新创业专项(2014-2-6)和兰州理工大学“红柳杰出人才”培养计划项目(J201404)。

Overexpression of ZxNHX and ZxVP1-1 genes from Zygophyllum xanthoxylum enhances sugar beet (Beta vulgaris) resistance to osmotic stress

WU Guo-Qiang^1,*, FENG Rui-Jun¹, WEI Jin-Kui¹, WANG Suo-Min², WANG Chun-Mei³

¹School of Life Sciences and Engineering, Lanzhou University of Technology, Lanzhou 730050, China; ²State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China; ³Lanzhou Institute of Husbandry and Pharmaceutical Science, CAAS, Lanzhou 730050, China

Corresponding author: WU Guo-Qiang; E-mail: wugq08@126.com

Abstract:

In the present study, to analyze drought tolerance of transgenic sugar beet (Beta vulgaris) plants overexpressing ZxNHX and ZxVP1-1 from Zygophyllum xanthoxylum, the changes of plant growth and accumulations of Na⁺, K⁺, proline and soluble sugars were investigated in transgenic and wild-type plants subjected with osmotic stress induced by sorbitol. The results indicated that osmotic stress significantly inhibited the growth of wild-type plants, and their leaf blade showed chlorosis and shrink, whereas transgenic plants still maintained the normal phenotype. Under osmotic stress, fresh weight and tissue water content in transgenic plants were higher 41% and 38% than those in wild-type plants, and the concentrations of Na⁺ and proline in shoot of transgenic plants increased by 1.2–1.5 folds and 40%–60%, respectively. Furthermore, K⁺ concentrations in shoot and root of wide-type plants were significantly decreased, while the Na⁺ relative distribution in leaf blade in transgenic plants were increased by 20% under osmotic stress. In addition, glucose and fructose contents in leaf blade and leaf petiole of transgenic plants were higher 35%–100% than wild-type plants subjected with osmotic stress. It was also observed that sucrose contents of storage root in transgenic plants were higher 6%–16% than those in wild-type plants. These results suggested that sugar beet plants overexpressing ZxNHX and ZxVP1-1 genes increased the sequestration of Na⁺ into vacuoles, and accumulated more Na⁺, Ca²⁺, proline, fructose and glucose in shoot, and more sucrose in storage root, thus led to enhance resistance to osmotic stress.

Key words: sugar beet (Beta vulgaris); drought tolerance; soluble sugar; ZxNHX; ZxVP1-1