干旱和盐胁迫对向日葵叶片蜡质积累的影响及蜡质烷烃合成基因的克隆  

Effects of drought and salt stresses on leaf wax accumulation and cloning of wax alkane synthesis genesin sunflower(Helianthus annuus L.)

作　　者：隗正阳 安沛沛 吴洪启[1] 刘乐 肖恩时 景兵[1] 王中华[1] WEI Zhengyang;AN Peipei;WU Hongqi;LIU Le;XIAO Enshi;JING Bing;WANG Zhonghua(College of Agriculture,Northwest Agriculture and Forestry University,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学农学院,陕西杨凌712100

出　　处：《干旱地区农业研究》2022年第6期56-62,共7页Agricultural Research in the Arid Areas

基　　金：国家特色油料产业技术体系向日葵杨凌综合试验站项目(CARS-14-2-21);国家自然科学基金项目(31601335);陕西省重点研发项目(2022NY-073)。

摘　　要：植物表皮蜡质在植物逆境胁迫响应中发挥重要作用。为了研究干旱和盐胁迫对向日葵叶片蜡质积累的影响,对三周龄向日葵分别进行干旱和盐胁迫处理,7 d后提取蜡质并利用气相色谱-质谱联用仪进行分析。结果表明:向日葵幼苗叶片蜡质主要由初级醇、烷烃和脂肪酸组成,其含量分别占蜡质总含量的79%、10%和9%。干旱和盐胁迫均没有改变向日葵幼苗叶片蜡质的组成,但是能够显著提高蜡质总含量,与对照相比,分别增加了8.8%和8.5%。所有蜡质组分中,烷烃含量变化最大,分别在干旱和盐胁迫后较对照增加了62.5%和47.0%,表明了向日葵幼苗叶片蜡质组分中,烷烃积极响应干旱和盐胁迫。为进一步研究参与向日葵蜡质烷烃合成的基因,在向日葵基因组中进行同源检索,共获得6个差异表达的候选基因,克隆了两个在叶片中表达水平较高的HaCER1-1和HaCER3-1。测序结果显示,HaCER1-1和HaCER3-1编码区长度分别为1869 bp和1674 bp,编码622个和557个氨基酸的蛋白质。利用qRT-PCR技术进一步分析了NaCl和PEG溶液处理下HaCER3-1的表达水平,结果显示,在处理后的12 h时,HaCER3-1在叶片中的表达分别增加了11倍和3.5倍,表明HaCER 3-1的表达受到干旱和盐胁迫的诱导。本研究为解析向日葵蜡质响应渗透胁迫和烷烃合成机制奠定了分子基础。Cuticular wax plays an important role in plant stress response.To study the effects of drought and salt stresses on wax accumulation of sunflower leaves,three-week-old sunflower plants were separately treated with drought and salt stresses.After seven days,leaf wax was extracted and analyzed by using gas chromatography-mass spectrometry.The results showed that the leaf wax of sunflower seedlings was mainly composed of primary alcohols,alkanes and fatty acids,which accounting for 79%,10%and 9%of the total wax content,respectively.Drought and salt stresses did not alter the composition of leaf wax in sunflower seedlings,but resulted in a significant increase in the total wax content by 8.8%and 8.5%respectively compared to the control.Among all wax components,the content of alkanes was the most influenced and increased by 62.5%and 47.0%compared to the control after drought and salt stresses,respectively.This indicated that alkanes in sunflower seedling leaves were more sensitive to drought and salt stresses than other wax components.To further study the genes involved in wax alkane formation in sunflower,a homology search was performed in the sunflower genome,and six differentially expressed candidate genes were obtained,in which HaCER1-1 and HaCER3-1 with higher expression levels in leaves were cloned.The sequencing results showed that the coding regions of HaCER1-1 and HaCER3-1 were 1869 bp and 1674 bp in length,encoding proteins of 622 and 557 amino acids,respectively.The expression levels of HaCER3-1 under the treatments of sodium chloride solution and PEG6000 solution were further analyzed by qRT-PCR technology.The results showed that the expression levels of HaCER3-1 in leaves were up-regulated by 11 times and 3.5 times at 12 h after treatments,indicating that the expression of HaCER3-1 was induced by drought and salt stress.This study provides some molecular foundation for dissecting the mechanisms of sunflower wax in response to osmotic stress and alkane biosynthesis.

关 键 词：向日葵 烷烃 基因表达 干旱胁迫 

分 类 号：S565.5[农业科学—作物学]