类酵母共生菌中两个组氨酸合成基因在褐飞虱发育中的作用  

Roles of Two Genes Involved in Histidine Biosynthetic Pathway in Yeast-Like Symbiont in Development of Nilaparvata lugens(Stl)

作　　者：唐耀华[1,2] 万品俊 郝培应[1] 傅强[2] 俞晓平[1] 

机构地区：[1]中国计量大学生命科学学院浙江省生物计量与检验检疫技术重点实验室,杭州310018 [2]中国水稻研究所水稻生物学国家重点实验室,杭州310006

出　　处：《中国水稻科学》2016年第4期406-416,共11页Chinese Journal of Rice Science

基　　金：国家自然科学基金资助项目(31371939);国家科技支撑计划资助项目(2012BAD19B03)

摘　　要：褐飞虱[Nilaparvata lugens（Stl）]是我国水稻上的主要害虫,专一性吸食必需氨基酸缺乏的水稻筛管液。利用基因组和转录组数据,人们构建了褐飞虱及其体内类酵母共生菌（YLS）参与组氨酸等必需氨基酸的合成途径。在此基础上,本研究旨在通过基因克隆和RNA干扰研究YLS的His2和His6（分别命名为EdeHis2和EdeHis6）在褐飞虱生长、发育和存活中的作用。同源搜索和系统发育分析表明EdeHis2和EdeHis6均源于YLS基因组,与绿僵菌His2和His6高度同源并在系统发育树中形成一个簇,但在褐飞虱基因组中无同源基因。基因的时空表达分析表明,His2和His6在褐飞虱的各个龄期均表达且呈现一定的波动性,在褐飞虱脂肪体中的表达量均显著高于头、足、体壁和中肠。此外,在褐飞虱头和翅的基因组中未能扩增到目的片段,而在腹部能扩增出目的片段。分别注射外源双链RNA（dsEdeHis2或dsEdeHis6）后的第2、4、6天,EdeHis2的表达量分别显著下调45%~60%,EdeHis6下调27%~55%。dsEdeHis2和dsEdeHis6分别使褐飞虱的死亡率提高了8.3%和9.2%,雌、雄虫的若虫期历期延长了0.43d、0.33d和0.65d、0.36d,但均未达到显著水平。另外,注射dsEdeHis6的褐飞虱雌雄成虫翅畸形率分别为11%和13%,显著高于对照组。综上所述,源于YLS的EdeHis2和EdeHis6参与褐飞虱组氨酸的合成,与褐飞虱的存活、发育和翅发育相关。Nilaparvata Lugens is a serious phloem-feeding pest of rice in China.Based on genome and transcriptome data of N.lugens and yeast-like symbiont（YLS,also named Entomomyces delphacidicola str.NLU）,the major biosynthesis pathways for amino acids in N.lugens were constructed.In this study,we cloned two genes,EdeHis2 and EdeHis6,which catalyze critical steps in histidine biosynthesis pathway,and revealed the negative effects of doublestranded RNA（dsRNA） on the growth,development and survival rate of N.lugens.Homology searches and phylogenetic analysis showed that EdeHis2 and EdeHis6 origin from YLS genome,share high similarities with that of Metarhiziurn acridurn and formed a clad in the phylogenetic tree,whereas no His2- or His6-like genes was found in N.lugens genome.Temporal expression profiles of EdeHis2 and EdeHis6 showed that both genes were ubiquitously but unevenly expressed among the different life stages,and the spatial expression pattern showed they have higher expression levels in the fat body rather than head,leg,integument and midgut.Furthermore,no target products were amplified in head and wing genomic DNA of N.lugens,rather than that in abdomen genomic DNA.At two,four and six days after dsEdeHis2 or dsEdeHis6 injection,the mRNA abundance of target genes was decreased by 45%-60%（EdeHis2）or 27%-55%（EdeHis6）,comparing with blank control.Down-regulation of EdeHis2 or dsEdeHis6 slightly increased the mortality by 8.3%or 9.2%,and delayed the nymphal duration of male and female by 0.43 and 0.65 day and 0.33 and 0.36 day,respectively.Moreover,both male（11%） and female adult（13%） showed wing deformation after injection of dsEdeHis6,higher than that in the blank control.In conclusion,EdeHis2 and EdeHis6 that origin from YLS were involved in histidine biosynthesis pathway,contributed to the survivor,development and wing formation of N.lugens.

关 键 词：褐飞虱 组氨酸 类酵母共生菌 His2 His6 RNA干扰 

分 类 号：S435.112.3[农业科学—农业昆虫与害虫防治] S476.12[农业科学—植物保护]