UV-B辐射增强对拟南芥表皮蜡质的影响  

Effect of enhanced ultraviolet-B radiation on epicuticular wax in Arabidopsis thaliana

作　　者：倪郁[1] 宋超[1] 李加纳[1] 

机构地区：[1]西南大学农学与生物科技学院、南方山地农业教育部工程技术中心,重庆400716

出　　处：《生态学报》2015年第5期1505-1512,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金(31000122,31270450);重庆市自然科学基金(cstc2012jj A80022);教育部作物资源利用创新引智基地(B12006)

摘　　要：以野生型拟南芥、蜡质不同程度缺失突变体CER1、CER3、CER4、CER6、CER10、CER20及KCS1为试验材料,通过施加50μW/cm2、长达10 d的UV-B辐射,研究了拟南芥表皮蜡质晶体结构、组分及蜡质基因对UV-B辐射的响应机制。结果表明:UVB辐射增强改变了拟南芥表皮蜡质晶体结构,表皮蜡质松针状(CER1)、柱状、杆状(CER3、CER10与KCS1)晶体结构显著减少,球状蜡质晶体类型出现在CER6表面,无规则片状、膜状结构覆盖在KCS1与CER10茎表面。野生型拟南芥蜡质晶体结构类型无明显变化,但在部分区域积累了大量水平杆状、管状结构,增加了蜡质层厚度。UV-B辐射增强也改变了拟南芥表皮蜡质组分的分泌量。野生型在UV-B处理后一级醇、酸、醛含量显著上升,烷、次级醇及酮含量显著下降,蜡质总量增加不显著。一级醇含量的增加及酮和次级醇含量的减少在拟南芥各材料响应UV-B辐射中具有普遍性。UV-B辐射增强诱导了野生型CER3、CER4、KCS1基因表达的上调,其中CER4大量表达,促进了蜡质组分中一级醇、酸和醛含量的积累;CER1在UV-B处理后表达量下调,可能导致烷合成下游分支途径相关产物(烷类、次级醇及酮类)的减少。WIN1表达量的下调对蜡质总量没有显著影响。UV-B辐射增强使蜡质前体从烷合成分支途径更多地转向一级醇分支途径。Due to the depletion of stratospheric ozone（ O3）,the quantity of UV-B radiation reached the earth＇s surface has increased significantly. Enhanced UV-B radiation influenced plant growth,development and productivity by damaging DNA,RNA,and proteins. Plants are thought to employ a variety of UV-B protective mechanisms,including accumulation of a range of secondary metabolites and adaptive changes in plant morphological features. As the outer surface of aerial plant tissues,the epicuticular wax is believed to play an important role in protecting plants against ultraviolet-B radiation.Epicuticular wax was composed primarily of saturated free fatty acids,aldehydes,alkanes,primary alcohols,secondary alcohols,ketones,and wax esters. Arabidopsis,as a model system to study the genetics and the molecular biology,has the typical structure and composition of cuticle,and it should be a model system to study the ecology of epicuticular waxes.However,little is known as to the responsees of different wax constituents to enhanced UV-B radiation,and the role of epicuticular waxes in providing protection for Arabidopsis from UV-B has not been examined either. Therefore,in the current study,seven wax mutants（ CER1,CER3,CER4,CER6,CER10,CER20 and KCS1） and wild type of A. thaliana were selected to analyze the responses of epicuticular wax in crystalloid structure,content and constituents,and wax related gene to UV-B radiation（ 50 μW / cm2）. The plants accepted UV-B radiation 2 h every day for consecutive 10 days. The resultsshowed that enhanced UV-B radiation altered the crystalloid structure of epicuticular wax on Arabidopsis stems. Under the enhanced UV-B radiation,amounts of pine needle-shaped crystalloids（ CER1）,columnar-shaped crystalloids and rods（ CER3、CER10 and KCS1） decreased significantly. Some small globular-shaped crystalloids appeared on the surface of CER6 mutant. Some irregular plate- and membrane-shaped structures covered the surface of KCS1 and CER10. No significant change of crystalloid types

关 键 词：拟南芥 表皮蜡质 基因 UV-B辐射 蜡质突变体 

分 类 号：Q947.8[生物学—植物学]