摘要
[目的]本文旨在探究逆境下BcGME基因与抗坏血酸(As A)含量的关系,为培育高品质的不结球白菜品种奠定理论基础。[方法]以不结球白菜‘苏州青’为材料,同源克隆了BcGME基因的全长,应用生物信息学分析了其氨基酸序列,通过实时荧光定量PCR技术测定了BcGME基因在过氧化氢胁迫和水淹胁迫下的表达水平,利用高效液相色谱(HPLC)测定了相应的抗坏血酸含量。[结果]BcGME基因包含一个长度为1 137 bp的开放式阅读框(ORF),编码379个氨基酸。推测其蛋白理论相对分子质量为42.97×103,理论等电点p I值为5.84,分子式为C1907H2949N519O570S22,属于不稳定蛋白。总平均疏水指数为-0.440,属于亲水蛋白。亚细胞定位预测该蛋白分布在细胞质中。BcGME氨基酸序列与十字花科大部分植物的相似性为90%以上,不结球白菜BcGME与十字花科的大白菜、甘蓝型油菜、拟南芥相应蛋白的进化距离较近。过氧化氢胁迫下,As A含量在6 h达到峰值,同时BcGME基因的表达量也达到最高;水淹胁迫下,1 d时As A含量最高为12.99μg·g^(-1),随后As A含量急速下降,1 d时的BcGME基因表达量是0 d的1.5倍。[结论]过氧化氢胁迫和水淹胁迫下,不结球白菜植株中BcGME基因的表达量变化趋势与As A含量变化趋势一致,说明GME可能是不结球白菜抗坏血酸合成途径中的关键调控基因。
[Objectives]The aim of the study is to investigate the relationship between BcGME and the content of ascorbic acid in non-heading Chinese cabbage,and cultivate high quality varieties of non-heading Chinese cabbage. [Methods]In this experiment,the full length of GDP-D-mannose-3＇,5＇-epimerase was cloned from non-heading Chinese cabbage. The amino acid sequence was analysed by bioinformatics. The expression level of BcGME was determined by quantitative real-time PCR and correspondingly the content of ascorbic acid was detected by high performance liquid chromatography（ HPLC） under hydrogen peroxide stress and waterlogging stress.[Results]The study indicated that the ORF length of BcGME was 1 137 bp,encoding 379 amino acids. The molecular weight of BcGME was 42.97×103,p I value was 5.84,and the molecular formula was C1907H2949N519O570S22,belonging to the unstable protein. BcGME grand average of hydropathicity was-0.440,which was the hydrophilic protein. Subcellular localization predicted that the protein was distributed in cytoplasm. The similarity of amino acid sequence between BcGME and most of the cruciferae was more than 90%.Phylogenetic analysis showed that BcGME was close to Brassica rapa subsp. pekinensis,Brassica napus,and Arabidopsis thaliana. Under hydrogen peroxide stress,after 6 h As A content reached peak,meanwhile BcGME gene expression level reached the highest. Under waterlogging stress,after 1 d As A content was the highest of 12. 99 μg·g^-1,then As A content decreased rapidly. At the same time,BcGME gene expression level was 1.5 times more than that of 0 d. [Conclusions]When under hydrogen peroxide stress and waterlogging stress,the variation trend of BcGME gene expression level and As A content was in consistent with each other,which shows that GME gene maybe a key regulatory gene in ascorbic acid biosynthesis pathway of non-heading Chinese cabbage.
出处
《南京农业大学学报》
CAS
CSCD
北大核心
2016年第2期205-212,共8页
Journal of Nanjing Agricultural University
基金
中央高校基本科研业务费自主创新重点研究项目(KYZ201111)
国家高技术研究发展计划(863计划)项目(2012AA100202)
江苏省科技支撑计划项目(BE2012325)
关键词
不结球白菜
BcGME
抗坏血酸
序列分析
非生物胁迫
Brassica campestris ssp
chinensis Makino
BcGME
ascorbic acid
sequences analysis
abiotic stress
