西瓜ClOr基因的克隆和表达分析  

Cloning and Expression Analysis of Cl Or Gene in Watermelon(Citrullus lanatus L.)

作　　者：朱子成[1,2] 崔喜波 邴文博 张其安 栾非时[1,2] Zhu Zicheng;Cui Xibo;BingWenbo;Zhang Qi'an;Luan Feishi(Key Laboratory of Biology and Genetic Improvement of Horticultural Crops(Northeast Region),Ministry of Agriculture and Rural Affairs,P.R.China,Northeast Agricultural University,Harbin,150030;College of Horticulture and Landscape Architecture,Northeast Agricultural University,Harbin,150030;Aolong Agriculture Limited Company in Heilongjiang,Harbin,150020;Institute of Horticulture Research,Anhui Academy of Agricultural Sciences,Hefei,230061)

机构地区：[1]东北农业大学,农业农村部东北地区园艺作物生物学与种质创制重点实验室,哈尔滨150030 [2]东北农业大学园艺园林学院,哈尔滨150030 [3]黑龙江傲龙农业有限公司,哈尔滨150020 [4]安徽省农业科学院园艺研究所,合肥230061

出　　处：《分子植物育种》2022年第21期6986-6993,共8页Molecular Plant Breeding

基　　金：国家重点研发计划-设施中早熟西瓜优质多抗适应性新品种培育(2018YFD0100703);国家西甜瓜产业技术体系-育种技术与方法岗位项目(CARS-25)共同资助。

摘　　要：植物细胞中质体是类胡萝卜素合成和储存中心,赋予花、果实和根等器官丰富色泽。Orange(Or)基因与质体分化及类胡萝卜素储存能力密切相关。本研究通过红色果肉西瓜材料LSW-177和浅黄色果肉西瓜材料COS克隆得到1个Or基因,将其命名为ClOr,该基因包含一个975 bp开放阅读框,编码324个氨基酸,理论等电点为7.5,预测分子量为35.81 kD。蛋白质序列分析表明,ClOr基因编码的蛋白在其序列N末端存在一个叶绿体导肽,中间区域包含两个跨膜结构域,在C末端还存在一个潜在的跨膜结构域。保守结构域分析显示,ClOr蛋白含有保守的锌指结构域以及典型的CXXCXXXG和CXXCXGXG催化结构域。进化树分析表明,西瓜来源的ClOr和同属葫芦科的甜瓜和苦瓜Or蛋白亲缘关系最为接近,而与水稻和玉米的Or蛋白关系最远。表达量分析结果显示,ClOr基因的表达量随西瓜果实发育而逐渐增加,直到果实完全成熟后(48 DAP)达到最大。在果实成熟过程中,红色西瓜LSW-177中ClOr基因表达量要远高于浅黄色西瓜COS。研究推测,在西瓜成熟过程中ClOr基因正向调控类胡萝卜素合成和储存。Plastids are the special organelles for carotenoid biosynthesis and storage in plant cells,which confer flowers,fruits and roots with a widely range of colors.The protein encoded by Orange(Or)gene could lead to the differentiation of chromoplasts and act as the key gene responsible for the capacity of carotenoids storage.In this study,an Or gene(named ClOr)had been isolated from red-flesh watermelon LSW-177 and pale-yellow flesh watermelon COS.ClOr gene contained a 975 bp open reading frame(ORF),encoding 324 amino acids with a theoretical isoelectric point(pI)of 7.5 and a predicted molecular weight of 35.81 kD.Protein sequence analysis showed a chloroplast transit peptide at the N terminus,two transmembrane regions in the middle and a potential transmembrane region at the C terminus.A highly conserved zinc-finger region,CXXCXXXG and CXXCXGXG motif had also been found in the ClOr protein sequence.Phylogenetic relationship analysis showed that ClOr was closely related with the proteins from Cucurbita melon and Cucurbita pepo,but distantly related to the ones from Oryza sativa subsp.japonica and Zea mays.The RT-qPCR results showed that the expression of ClOr was increased along with the watermelon fruit ripening and reached the peak at 48 DAP.During ripening period,the expression of ClOr gene is higher in red-flesh LSW-177 than that in pale-yellow flesh COS.It is speculated that ClOr gene positively regulates carotenoid synthesis and storage during watermelon ripening.

关 键 词：西瓜 质体 类胡萝卜素 Or基因 

分 类 号：S651[农业科学—果树学]