山西农业大学学报（自然科学版）2025，Vol.45Issue(3)：54-63,10.DOI:10.13842/j.cnki.issn1671-8151.202501026
拟南芥蜡质突变体gs1的鉴定和突变基因克隆
Identification of the Arabidopsis wax mutant gs1 and cloning of the associated mutant gene
摘要
Abstract
[Objective]Cuticular wax is a hydrophobic barrier on the surface of terrestrial plants.Screening and identifying Arabi-dopsis wax-deficient mutants can help further elucidate the biosynthetic pathways of plant epidermal wax.[Methods]The glossy stem mutant glossy stem 1(gs1)was isolated from an ethyl methyl sulfone(EMS)-mutagenized Arabidopsis mutant population(Col-0 background).The wax crystal structure of stems and leaves in gs1 were systematically analyzed using scanning electron microscope(SEM)and gas chromatography(GC).Candidate mutant genes were then identified,and their functions were vali-dated through heterologous expression in yeast and genetic complementation in Arabidopsis.[Results]Compared with the wild type,the stem epidermis of gs1 mutant appeared significantly smoother,with nearly complete loss of wax crystal structure.GC analysis revealed a sharp decrease in wax content in both leaves and stems of the gs1,accompanied by a significantly reduction in C28 and longer-chain wax monomers and a notable increase in C24-C26 chain-length wax monomers.Candidate gene screen-ing based on this wax composition changes,combined with resequencing,a G1384A single-nucleotide mutation in CER6/KCS6,a key gene encoding β-ketoacyl-CoA synthase in wax biosynthesis.This mutation converted a UGG codon into a pre-mature stop codon UGA in the mRNA,which caused the truncated protein translation and loss of the ACP_syn_III domain in protein.Subsequently,CER6/KCS6 was cloned from both wild-type and gs1 mutant and heterologously expressed in yeast.Fatty acid analysis confirmed that the single-base mutation in gs1 completely abolished the function of CER6/KCS6,rendering it incapable of synthesizing C26 and C28 very-long-chain fatty acids in yeast.Additionally,transgenic complementation lines(gs1R1 and gs1R2)were generated by introducing CER6pro::CER6-GFP,into gs1.SEM and GC analyses showed that wax content in the leaves of gs1R1 and gs1R2 were restored to wild-type levels,while stem wax content was partially restored.[Conclusion]The gs1 mutant carried a G1384A mutation in CER6/KCS6,resulting in premature translational termination and loss of β-ketoacyl-CoA synthase activity.This ultimately disrupted wax accumulation in Arabidopsis leaves and stems.关键词
拟南芥/蜡质/超长链脂肪酸/β-酮脂酰CoA合成酶Key words
Arabidopsis/Wax/Very-long-chain fatty acid/β-ketoacyl-CoA synthase分类
农业科技引用本文复制引用
李梦娇,范帆,杨贤鹏,崔莉莉..拟南芥蜡质突变体gs1的鉴定和突变基因克隆[J].山西农业大学学报（自然科学版）,2025,45(3):54-63,10.基金项目
国家自然科学基金青年基金项目(42207445) （42207445）
山东省自然科学基金青年基金项目(ZR2021QD017) （ZR2021QD017）
