番茄ABC家族G亚族(ABCGs)的全基因组鉴定和表达分析

Genome-wide Identification and Expression Analysis of ABC Family G Subfamily(ABCGs)in Tomato

在植物中,ATP结合盒(ATP-binding cassette,ABC)转运蛋白是一个较大的膜转运蛋白家族,它在拟南芥(Arabidopsis thaliana)、水稻(Oryza sativa)、菠萝(Ananas comosus)、巴西橡胶树(Hevea brasiliensis)、番茄(Solanum lycopersicum)、葡萄(Vitis vinifera)、蒺藜苜蓿(Medicago truncatula)等植物中均有报道。在ABC转运蛋白家族中,G亚家族是其中最大的一个亚族,其功能广泛,但在番茄中的研究尚不清楚。本研究对番茄进行了转录组数据分析,结果表明ABCG亚家族响应低温胁迫和脱落酸(abscisic acid,ABA)胁迫。因此,本研究运用生物信息学手段,对SlABCG基因家族的成员进行鉴定,并通过系统进化树分析、染色体定位分析、内含子/外显子分布、保守基序分析、组织定位分析和胁迫反应分析等实验,探讨了番茄ABCG亚家族的特性和功能。同时,根据番茄ABCG基因在染色体上的位置,对其进行了命名,再结合ABCG基因家族的结构、启动子顺式作用元件的作用以及ABCG基因在脱落酸和低温胁迫下的基因表达的结果,明确ABCG基因家族的特性。实时定量PCR结果显示,在低温胁迫下SlABCG5、SlABCG22、SlABCG24、SlABCG38基因表达明显上调,ABA处理后SlABCG16表达明显上调。同时,对SlABCG24的拟南芥同源蛋白AtABCG9进行了研究,通过STRING网站预测其与低温信号途径中关键蛋白OST1、HOS1和ICE1存在相互作用。这些结果为研究番茄ABCG基因家族的功能提供一定理论基础。

In plants,the ATP-binding cassette(ABC)transporters is a large protein family which has been broadly studied in many plants including Arabidopsis thaliana,Oryza sativa,Ananas comosus,Hevea brasiliensis,Solanum lycopersicum,Vitis vinifera,Medicago truncatula and other crops.In the ABC transporter family,G subfamily is the largest one with a wide range of functions,but the research in tomato is not clear.In this article,genome-wide analysis of ATP binding cassette(ABC)transporters G subfamily in tomato has started.RNA-seq analysis in tomato showed that the ABCG subfamily were sensitive to cold stress and abscisic acid(ABA).Therefore,we explored the characteristics and functions of tomato ABCG subfamily through bioinformatics analysis,including reidentification of SlABCG gene family members,phylogenetic analysis,chromosome localization,intron/exon distribution,conservative motifs,cis-acting elements,tissue localization and stress response.At the same time,the ABCG gene was named according to the position of tomato ABCG gene on chromosome,and then combined with the structure of ABCG gene family,the function of promoter cis-acting element,and the results of ABCG gene expression under abscisic acid and low temperature stress,the characteristics of ABCG gene family were determined.Real-time quantitative PCR results showed that four genes(SlABCG5,SlABCG22,SlABCG24,SlABCG38)were up-regulated obviously under low temperature stress and SlABCG16 was up-regulated after ABA treatment.Meanwhile,the homologous protein of SlABCG24 in Arabidopsis thaliana,AtABCG9,was queried which interacted with cold-resistant proteins OST1,HOS1 and ICE1.These results provide valuable evidence for the functional properties of the SlABCG gene family in tomato.