二氧化硫增强拟南芥植株对干旱的适应性

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 二氧化硫增强拟南芥植株对干旱的适应性 DOI: 10.5846/stxb201701110090 作者: 作者单位: 山西大学,山西大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（30870454，30470318，31371868）；高等学校博士学科点专项科研基金项目（20070108007，20121401110007） Sulfur dioxide improves drought adaptation in Arabidopsis plants Author: Affiliation: Shanxi University,Shanxi University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以模式植物拟南芥为材料，研究SO2对植物干旱适应性的影响。采用分光光度法检测植物干旱生理指标的变化，并用半定量RT-PCR技术分析了拟南芥热激基因和干旱响应基因的转录水平。研究发现：4周龄拟南芥植株暴露于30mg/m3的SO2后，6-72h间叶面气孔开度显著低于对照并逐渐减小，在暴露48h和72h时，热激转录因子HsfA2和热激基因Hsp17.7、Hsp17.6B、Hsp17.6C转录上调，干旱响应基因DREB2A、DREB2B和RD29A表达增强；在SO2熏气72h后进行干旱胁迫，干旱期间SO2预暴露植株的叶片相对含水量高于非熏气干旱处理组，植株萎蔫程度比后者明显减轻，且SO2预暴露植株的地上组织中可溶性糖和脯氨酸含量升高，超氧化物歧化酶活性提高，丙二醛含量降低。结果表明：SO2能降低气孔开度、提高抗氧化能力、上调热激基因和干旱响应基因转录，并能促进干旱期间植物细胞内渗透调节物质的合成和积累，促使抗氧化酶活性提高，从而降低干旱胁迫对植株造成的氧化损伤，增强拟南芥对干旱的适应性。植物通过基因转录应答、酶活性改变、渗透调节物质积累等，在适应环境高浓度SO2的同时，提高了对干旱的适应性。 Abstract:Plants have evolved some important mechanisms of adaptation to environmental stress. Plants might respond to multiple environmental factors simultaneously. The cross adaptation of plants provides mechanisms for plant survival under multiple stress conditions. Plant cross adaptation has been observed to occur under low/high temperature and drought stress as well as under saline and drought stress. Sulfur dioxide (SO2) is a common air pollutant with harmful effects on plants. However, it is not clear how plants respond to simultaneous changes in air SO2 concentration and availability of soil water. In this study, effects of SO2 exposure on the adaptation of plants to drought stress were investigated using Arabidopsis. The results showed that exposure to 30mg/m3 SO2 for 6 to 72 h significantly decreased stomatal aperture in Arabidopsis leaves. The transcriptional levels of heat shock transcription factor HsfA2 and its target genes encoding heat shock proteins Hsp17.7, Hsp17.6B and Hsp17.6C were increased after 48h and 72h of exposure to SO2. The expression of three tested drought-responsive genes DREB2A, DREB2B and RD29A in Arabidopsis were also up-regulated in SO2-fumigated Arabidopsis shoots after 48h and 72h of exposure. Moreover, pretreatment with SO2 caused higher relative water content and low degrees of wilting in Arabidopsis plants under drought stress, indicating improved drought adaptation in SO2-fumigated plants. The contents of soluble sugar and proline were increased in SO2-fumigated Arabidopsis plants, and these increases were accompanied by increases in antioxidant enzyme activity and low malondialdehyde content. The results indicate that SO2 exposure improves plant adaptation to drought stress through regulating stomatal closure, gene transcription and metabolic pathways. The improved antioxidant capacity and increased synthesis and accumulation of osmolytes in SO2-fumigated Arabidopsis plants help to prevent negative effects of drought stress and to enhance plant adaptation to drought stress. 参考文献 相似文献 引证文献