《植物生理学报》 2015, 51(11): 2054-2062

转TPS1基因促进干旱胁迫条件下的花青素积累提高玉米植株抗旱性

项阳¹, 刘延波¹, 赵德刚^1,*, Yi Li²

¹贵州大学生命科学学院, 农业生物工程研究院, 山地植物资源保护与种质创新省部共建教育部重点实验室, 贵阳550025; ²Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT 06269, USA

通信作者：赵德刚；E-mail: dgzhao@gzu.edu.cn；Tel: 0851-83863615

摘　要：

以不同浓度的PEG-6000溶液模拟干旱胁迫条件, 研究转TPS1基因玉米植株抗旱性增强的原因。结果表明, 随着干旱胁迫加重, 野生型和转基因玉米植株的叶片相对含水量和耐旱系数逐渐降低; 但转基因玉米植株叶片相对含水量和耐旱系数高于野生型, 表明转基因玉米植株比野生型更抗旱。同时随着干旱加重, 野生型和转基因玉米植株花青素含量也随之增加, 且转基因玉米植株的花青素含量高于野生型。相关性分析表明, 花青素含量与转基因玉米抗旱性增强显著相关。干旱胁迫前, 转TPS1基因玉米植株花青素含量与野生型植株无显著差异, 而在10% PEG-6000模拟干旱胁迫条件下, 转TPS1基因玉米植株根、茎、叶的花青素含量极显著高于野生型, 分别是野生型的8.5、5.4和1.8倍。分析调控花青素合成基因的相对表达量结果表明, 正调控基因PL1、R1和PAC1在转基因植株根、茎、叶中表达均上调, 而负调控基因c1-I-2K1在根、茎、叶中表达下调。表明TPS1基因的表达影响花青素合成调控基因的表达促进花青素积累, 进而提高植株抗旱性。此外, 干旱胁迫后, 转基因植株的CAT活性比野生型高56.3%, MDA含量比野生型低36.7%, 说明TPS1基因的表达提高了玉米抗氧化能力。

关键词：玉米; TPS1基因; 花青素; 抗旱性

收稿：2015-09-23   修定：2015-11-02

资助：国家转基因生物新品种培育科技重大专项子课题(2014ZX0801008B-002和2014ZX08010-003)和贵州省科技厅转基因专项(黔科合2004NZ004)。

Improve Drought Tolerance via Accumulating Anthocyanidin under Drought Stress in TPS1 Transgenic Maize

XIANG Yang¹, LIU Yan-Bo¹, ZHAO De-Gang^1,*, Yi Li²

¹The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region, Ministry of Education, College of Life Sciences and Institute of Agro-Bioengineering, Guizhou University, Guiyang 550025, China; ²Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT 06269, USA

Corresponding author: ZHAO De-Gang; E-mail: dgzhao@gzu.edu.cn; Tel: 0851-83863615

Abstract:

In this paper, we studied mechanism of transgenic maize plants drought-resistant enhancement based on former studies. Under different concentrations of PEG-6000 solution simulated drought stress conditions, leaf relative water content and drought-resistant coefficient of wild type and transgenic maize plants decreased with aggravating drought degree; and under conditions of each degree, both leaf relative water content and drought-resistant coefficient of genetically modified maize plants was higher than wild type, which indicated drought resistance of transgenic plants was more than wild type. At the same time, with drought aggravating, anthocyanin content also increased in wild type and transgenic maize plants, and that of transgenic maize plants were higher than wild type in each drought stress condition. Correlation analysis showed anthocyanin content in transgenic plants had significantly correlated to drought resistance. Anthocyanin content in roots, stems and leaves of wild-type and TPS1 transgenic maize plants was no significant difference before drought stress, but that of transgenic maize was significantly higher than wild type under drought stress, representing an increase of 8.5, 5.4 and 1.8 folds, respectively. Gene expression analysis of transcription factors that regulating anthocyanin biosynthesis showed that relative expression of positive regulator gene PL1, R1, PAC1 was up-regulated, and that of negative regulator gene c1-I-2K1 was down-regulated in roots, stems and leaves of transgenic maize, which suggested that transcription factors were influenced anthocyanin accumulation by TPS1 in roots, stems and leaves of TPS1 transgenic maize, and then improved drought resistance of plants. Results also showed that CAT activity and MDA content were no significant difference between transgenic plants and wild type before drought stress, but compared with wild type plants, CAT activity was increased 56.3% and MDA content was decreased by 36.7% in transgenic plants after drought stress, which suggested TPS1 gene increased the antioxidant capacity of maize result in improving maize drought resistance.

Key words: maize; TPS1 gene; anthocyanidin; drought tolerance