摘要
【目的】探明芥菜型油菜黄化突变体L638-y叶片氨基酸合成代谢网络变化。【方法】以芥菜型油菜黄化突变体L638-y及其野生型L638-g为材料,用氨基酸自动分析仪及实时定量PCR,检测并分析了幼苗叶片游离氨基酸含量及氨基酸合成代谢中8个重要基因的相对表达量。【结果】1)芥菜型油菜黄化突变体L638-y幼苗叶片游离氨基酸总量低于野生型L638-g,被检测出的17种游离氨基酸中,有10种氨基酸含量低于野生型L638-g,而其他7种则高于野生型L638-g;各游离氨基酸的含量在突变体L638-y与野生型L638-y叶片之间变化幅度不尽相同,其中差异显著的是甘氨酸、甲硫氨酸、异亮氨酸、亮氨酸、酪氨酸、精氨酸,谷氨酸的变化最小。2)氨基酸合成代谢中8个重要基因表达量变化的分析结果表明,仅谷氨酸族氨基酸生物合成的谷氨酸合酶基因(GSR)的表达在L638-y中呈上调表达趋势,其余的7个基因,即谷氨酰胺合成酶基因(GLN)、天冬氨酸氨基转移酶基因(GOT)、天冬酰胺合成酶基因(ASN)、Δ′-二氢吡咯-5-羧酸还原酶基因(P5CR)、丙氨酸氨基转移酶基因(AAT)、3-磷酸甘油酸脱氢酶基因(PGDH)、ATP磷酸核糖转移酶基因(ATP-PRT)均下调表达。3)在突变体L638-y叶片氨基酸合成代谢途径中,8个重要基因表达量的变化与相关游离氨基酸含量的变化并不一致,表明氨基酸合成代谢受到了抑制。【结论】芥菜型油菜黄化突变体L638-y幼苗叶片中氨基酸合成代谢和氮代谢受到了抑制。
【Objective】 The study was done to reveal the network of amino acids biosynthesis in leaves of chlorophyll-deficient Brassica juncea mutant L638-y.【Method】 The chlorophyll-deficient mutant L638-y and wild-type L638-g of B.juncea were used as the materials to examine the contents of free amino acids and relative expression levels of some important genes in amino acids synthetic metabolism.【Result】 1）The results showed that total free amino acids content in mutant L638-y seedling leaves was lower than that in wild-type L638-g;Among seventeen kinds of free amino acids,the contents of ten amino acids were lower in mutant L638-y seedling leaves than that in wild-type L638-g,and the rest were higher;and the content and rangeability of free amino acids in the mutant L638-y and wild type L638-g seedling leaves were different,among them Gly,Met,Ile,Leu,Tyr,Arg had more significant difference between mutant and wild-type,and changes of Asp and Glu were the smallest;2） Expression changes of eight genes in amino acids synthetic metabolism showed that only GSR was up-regulated in L638-y,the rest seven genes,GLN,GOT,ASN,AAT,P5CR,PGDH,ATP-PRT were down-regulated.3） The gene expression changes were not consistent with the free amino acids content changes in mutant L638-y seedling leaves,and amino acids synthetic metabolism was inhibited.【Conclusion】 Amino acids synthetic metabolism and nitrogen metabolism in the seedling leaves of chlorophyll-deficient B.juncea mutant L638-y were inhibited.
出处
《西北农林科技大学学报（自然科学版）》
CSCD
北大核心
2012年第2期27-34,共8页
Journal of Northwest A&F University(Natural Science Edition)
基金
国家油菜产业技术体系资助项目(nycytx-00505)
