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十字花科植物芥酸合成基因FAE1

花匠小妙招
2024-09-17 19:35

Cloning and functional analysis on erucic acid synthesis gene FAE1-closest in Brassicaceae plants

摘要

对十字花科（Brassicaceae）中具代表性的高、低芥酸植物的FAE1-closest基因进行扩增，并对其编码的氨基酸序列进行序列比对；基于FAE1-closest氨基酸序列构建遗传关系树；将具有代表性的FAE1-closest基因在酵母中进行转化，比较不同植物来源的该基因调控芥酸合成能力的差异。结果显示：十字花科高、低芥酸植物FAE1-closest基因编码的氨基酸序列主要有A和B 2种类型，其对应的编码区全长分别约为1 461和1 389 bp，且B类型的氨基酸序列仅出现在高芥酸植物中；比较氨基酸序列的变异位点发现，高、低芥酸植物中共存在150个变异位点，高芥酸植物中第320位的氨基酸为赖氨酸（K），低芥酸植物中该位点为苏氨酸（T）。遗传关系树显示：12种芥酸植物可聚为Ⅰ和Ⅱ2个分支，大部分高芥酸植物的FAE1-closest氨基酸序列聚在分支Ⅰ；高芥酸植物银扇草（Lunaria annua Linn.）以及低芥酸植物涩荠〔Malcolmia africana (Linn.) R. Br.〕、鸟头荠〔Euclidium syriacum (Linn.) R. Br.〕和四齿芥〔Tetracme quadricornis (Stephan) Bunge〕的FAE1-closest氨基酸序列聚在分支Ⅱ。酵母转化实验结果显示：蔓菁（Brassica rapa Linn.）和洋基芥（Brassica tournefortii Gouan）的FAE1-closest基因转酵母产物中检测到了芥酸，涩荠、鸟头荠、四齿芥和银扇草的FAE1-closest基因转酵母产物中均未检测到芥酸，说明只有部分十字花科植物的FAE1-closest基因与芥酸合成相关。综上所述，低芥酸植物来源的FAE1-closest基因均不能合成芥酸，部分高芥酸植物来源的FAE1-closest基因能合成芥酸，不同十字花科植物中的FAE1-closest基因在芥酸合成过程中发挥作用的程度不同；FAE1-closest基因是否为芥酸合成过程中的主效基因，有待进一步验证。

Abstract

Amplification was conducted for FAE1-closest genes of representative high and low erucic acid plants in Brassicaceae, and sequence alignment of the amino acid sequences encoded by FAE1-closest genes was performed; a genetic relation tree was constructed based on the amino acid sequences of FAE1-closest; representative FAE1-closest genes were transformed into yeast, and the differences in regulation of erucic acid synthesis ability among FAE1-closest genes from different plants were compared. The results show that the amino acid sequences encoded by FAE1-closest genes of high and low erucic acid plants in Brassicaceae have two types namely A and B, the full length of their corresponding coding regions are about 1 461 and 1 389 bp respectively, and amino acid sequences of B type only appear in high erucic acid plants; by comparing the amino acid sequence variation sites shows that there are 150 variation sites in high and low erucic acid plants in total, and the 320th amino acid in high erucic acid plants is lysine (K), while that in low erucic acid plants is threonine (T). The genetic relation tree shows that 12 erucic acid plants can be divided into two clades namely Ⅰ and Ⅱ, and the amino acid sequences of FAE1-closest of most high erucic acid plants are clustered into clade Ⅰ; those of high erucic acid plant Lunaria annua Linn. and low erucic acid plants Malcolmia africana (Linn.) R. Br., Euclidium syriacum (Linn.) R. Br., and Tetracme quadricornis (Stephan) Bunge are clustered into clade Ⅱ. The yeast transformation experiment result shows that erucic acid can be detected in yeast transformed products of FAE1-closest genes from Brassica rapa Linn. and Brassica tournefortii Gouan, but not in yeast transformed products of FAE1-closest genes from M. africana, E. syriacum, T. quadricornis, and L. annua, indicating that only FAE1-closest genes of some Brassicaceae plants are associated with erucic acid synthesis. In conclusion, FAE1-closest genes from all low erucic acid plants cannot synthesize erucic acid, and FAE1-closest genes from some high erucic acid plants can synthesize erucic acid; the function degree of FAE1-closest genes in different Brassicaceae plants are different in process of erucic acid synthesis; whether FAE1-closest gene is the major gene involved in erucic acid synthesis needs to be further verified.