甜橙SUT家族基因响应柑橘溃疡病的表达分析及SUT2功能验证  

Identification of SUTs Family in Sweet Orange and Preliminary Analysis of SUT2 Function in Response to Xcc Induced

作　　者：麻明英 张凯 文康[1] 肖桂华 郝晨星 朱亦赤[1,2,3] Ma Mingying;Zhang Kai;Wen Kang;Xiao Guihua;Hao Chenxing;Zhu Yichi(College of Horticulture,Hunan Agricultural University,Changsha,410128;Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding(Ministry of Education),College of Horticulture,Hunan Agricultural University,Changsha,410128;National Center for Citrus Improvement Changsha,Changsha,410128)

机构地区：[1]湖南农业大学园艺学院,长沙410128 [2]湖南农业大学园艺学院,教育部园艺作物种质创新与新品种选育工程研究中心,长沙410128 [3]国家柑橘改良中心长沙分中心,长沙410128

出　　处：《分子植物育种》2024年第6期1823-1833,共11页Molecular Plant Breeding

基　　金：国家重点研发计划项目(2018YFD10003000);湖南省自然科学基金项目(2020JJ4040)共同资助。

摘　　要：柑橘溃疡病是危害柑橘产业的细菌性病害,病原菌定殖在细胞间隙,其增殖所需营养物质主要来源于通过调控寄主糖转运蛋白供给的糖类物质。蔗糖糖转运蛋白(sucrose transporters, SUC/SUT)属于植物体内广泛存在的一类糖转运蛋白,在植物与病原菌相互作用过程中起重要作用。为探究SUTs基因在柑橘响应黄单胞杆菌属柑橘致病变种(Xanthomonas citri subsp. citri, Xcc)侵染过程中发挥的作用,首先通过生物信息学分析,检索出7个SUTs基因,分布在5条染色体上,含有4~13个外显子,编码348~606个氨基酸,蛋白分子量(kD)为38 626.32~64 921.00,等电点(pI) 5.42~9.09,70%为碱性的疏水性蛋白,根据甜橙SUTs基因所含有的保守基序将其分为2、3、4分支。其次,通过对感病种质冰糖橙和抗病种质枸橼C-05接种Xcc,实时荧光定量PCR (RT-qPCR)结果显示SUT2受Xcc诱导在冰糖橙叶片上调表达而在枸橼C-05叶片上无显著性变化,其余SUTs在冰糖橙和枸橼C-05中受Xcc诱导均无显著性变化。冰糖橙和枸橼C-05 SUT2同源基因编码的氨基酸序列比对显示,相似性为98.5%,两种质SUT2其启动子顺式作用元件分析发现,二者的种类和数量差异较小,仅冰糖橙特有motifⅠ(根特异元件)。在感病种质冰糖橙和抗病种质枸橼C-05瞬时超表达SUT2结果显示,两种质叶片过表达区域水渍状症状比对照P0明显,且单位叶面积Xcc含量显著高于P0对照,初步说明SUT2蛋白对Xcc的生长有明显的促进作用。Citrus canker disease is a bacterial disease that harms citrus industry.The pathogen colonizes in the intercellular space,and the nutrients needed for its proliferation mainly come from the carbohydrate supplied by regulating the host sugar transporters.Sucrose Transporters(SUC/SUT)belong to a class of sugar transporters widely existing in plants,it plays an important role in the interaction between plants and pathogens.To explore the role of SUTs family in Citrus response to Xanthomonas citri subsp.citri(Xcc)infection.Firstly,seven SUTs were identified by bioinformatics analysis,distributed on five chromosomes,containing 4 to 13 exons,encoding 348 to 606 amino acids.The protein molecular weight(kD)was 38626.32 to 64921.00,the theoretical isoelectric point(pl)was 5.42 to 9.09,and the hydrophobic protein was 70%basic.According to the conserved motif of SUTS gene in orange,it was divided into branches 2,3 and 4.Secondly,by inoculating the susceptible germplasm Bingtang Orange and resistant germplasm Citron C-05 with Xcc,the results of real-time quantitative PCR showed that SUT2 was up-regulated in the leaves of Bingtang Orange induced by Xcc,but had no significant change in the leaves of Citron C-05.There was no significant change in other SUTs induced by Xcc in Bingtang Orange and Citron C-05.Amino acid sequence alignment of SUT2 homologous gene in Bingtang Orange and Citron C-05 showed 98.5%similarity.Analysis of cis-acting elements of promoter of SUT2 between the two germplasms showed lttle difference in species and number,and only specific motif I(root specific components)were found in Bingtang Orange.The results of transient overexpression of SUT2 in susceptible Bingtang Orange and resistant germplasm Citron C-05 showed that the symptoms of water stain were more obvious in overexpression area of leaves of both germplasms than that of control Po,and the content of Xcc per unit leaf area was significantly higher than that of control PO,suggesting that SUT2 protein had a significant promoting effect on the growth

关 键 词：柑橘 柑橘溃疡病 蔗糖转运蛋白家族 SUT2 

分 类 号：S436.66[农业科学—农业昆虫与害虫防治]