罗布麻和大麻状罗布麻UV-B光受体UVR8基因的鉴定及表达分析

Identification and expression analysis of UV-B photoreceptorUVR 8 genes in Apocynum venetum and A. cannabinum

在植物响应紫外线B(ultraviolet-B,UV-B)的过程中,UV-B光受体UVR8(UV Resistance Locus 8)对植物的光形态建成和生长代谢等过程具有重要调控作用。为探究罗布麻属植物UV-B光受体信息,该研究通过罗布麻(Apocynum venetum)和大麻状罗布麻(A.cannabinum)全基因组数据进行UV-B光受体UVR8的筛选与生物信息学分析,同时利用转录组数据分析UV-B胁迫处理下的UVR8基因表达模式。结果表明:(1)罗布麻有6个UVR8基因,大麻状罗布麻有5个UVR8基因,前者分布在1、7、9和11号染色体上,后者分布在1、8和9号染色体上。(2)UVR8蛋白为亲水性稳定蛋白,定位在细胞核,不存在跨膜结构和信号肽,二级结构主要由延伸链、无规则卷曲、α-螺旋和β-转角构成。AvUVR8b和AcUVR8a蛋白三级结构与拟南芥UVR8(AtUVR8)最为类似,并且与小粒咖啡(CaUVR8)和伊德斯种咖啡(CeUVR8)的亲缘关系最近。同时发现罗布麻AvUVR8b和大麻状罗布麻AcUVR8a基因和蛋白结构与AtUVR8基因及蛋白高度相似。(3)当以一定剂量UV-B(17.52 kJ·m~(-2)·d~(-1))处理两种罗布麻植株时,AvUVR8b和AcUVR8a的表达量上调。据此推测在响应UV-B时,AvUVR8b基因在罗布麻中起主要作用,AcUVR8a基因在大麻状罗布麻中起主要作用。(4)顺式作用元件分析结果表明,UVR8的表达受光照、温度、水分、氧气和激素等因素的调控。该研究将为进一步研究罗布麻属UVR8的基因功能奠定基础,同时为解析罗布麻属植物适应UV-B的分子机制提供线索。

In the processes of plants response to UV-B,the UV-B photoreceptor UVR8(UV Resistance Locus 8)plays an important role in the regulation of photomorphogenesis,growth and metabolism of plants.To investigate the UV-B photoreceptors of Apocynum plant,this study is conducted to screen and bioinformatically analyze the UV-B photoreceptors UVR8 by the whole genome data of Apocynum venetum and A.cannabinum,and also to analyze the UVR 8 gene expression pattern under UV-B stress treatment using transcriptome data.The results were as follows:(1)There were six UVR 8 genes in A.venetum,and five UVR 8 genes in A.cannabinum.The former was distributed on chromosomes 1,7,9 and 11,and the latter on chromosomes 1,8 and 9.(2)UVR8 proteins were all hydrophilic stable proteins,localized in the nucleus,without transmembrane structure or signal peptides.The secondary structure consists mainly of extended strand,random coil,alpha helix and beta turn.The tertiary structures of AvUVR8b and AcUVR8a were most similar to that of Arabidopsis thaliana and were most closely related to Coffea arabica(CaUVR8)and C.eugenioides(CeUVR8).The gene and protein structures of Apocynum venetum AvUVR 8 b and A.cannabinum AcUVR 8 a were highly similar to those of AtUVR 8.(3)The expression levels of AvUVR 8 b and AcUVR 8 a were up-regulated when the two Apocynum plants were treated with a certain dose of UV-B(17.52 kJ·m-2·d-1).It is speculated that in response to UV-B,the AvUVR 8 b in A.venetum and the AcUVR 8 a in A.cannabinum play a major role,respectively.(4)The analysis of cis-acting elements showed that the expression of UVR 8 was regulated by light,temperature,moisture,oxygen and hormones.This study will lay a foundation for further research on the gene function of UVR 8 in Apocynum,and provide clues to analyze the molecular mechanism of UV-B adaptation in the Apocynum.