猕猴桃蔗糖合成相关酶SUS与SPS基因的鉴定与表达分析

Identification and Expression Analysis of Sucrose Synthase(SUS)and Sucrose Phosphate Synthase(SPS)Genes in Kiwifruit

蔗糖合酶(SUS)和蔗糖磷酸合成酶(SPS)基因是高等植物蔗糖代谢的关键酶。为了探究猕猴桃SUS和SPS基因在蔗糖代谢中的作用,本研究以‘红阳’和‘华特’为试材,进行了全基因组鉴定与基因结构、系统发育关系、保守域分析、染色体定位和基因进化模式分析,并结合转录组数据分析了SUS和SPS基因的表达特征。结果表明,猕猴桃中包含8个SUS基因(AchSUS1~AchSUS8)和5个SPS基因(AchSPS1~AchSPS5),其中,SUS家族基因分为3个亚家族,分别为SUSⅠ、SUSⅡ和SUSⅢ;SPS基因家族分为4个组,分别为SPSA、SPSB、SPSC和SPSD。猕猴桃SUS和SPS基因家族成员不均匀地分布在11条染色体上,存在7对旁系同源基因,分别经历了片段重复和猕猴桃种内全基因组复制事件,SUS基因在SUSⅢ中的扩张得以保留,且这些基因在进化过程中受纯化选择作用。表达分析发现,所有SPS基因和4个SUS基因在‘红阳’和‘华特’中的表达呈现极显著差异,其中AchSUS7在‘红阳’中特异表达。这些基因可能在猕猴桃糖分积累和品质形成中起着重要作用。

Sucrose synthase(SUS)and sucrose phosphate synthase(SPS)genes are key enzymes in sucrose metabolism in higher plants.To study the roles of SUS and SPS genes in the sucrose metabolism in kiwifruit(Actinidia chinensis),we used the sequenced genomes'Hongyang'and'White'for genome-wide research,including gene identification and genetic structure analysis,phylogenetic relationships detection,conservative domain analysis,chromosome located and genetic evolution pattern analysis.Transcriptome data was used to analyze the expression patterns of SUS and SPS genes.The results showed that there were eight SUS genes(AchSUS1~AchSUS8)and five SPS genes(AchSPS1~AchSPS5)in kiwifruit genome.The SUS family genes were divided into three subfamilies(SUSⅠ,SUSⅡand SUSⅢ).The SPS family memberswere divided into four groups(SPSA,SPSB,SPSC and SPSD).Members of the SUS and SPS genes were unevenly located on 11 chromosomes.Seven pairs of paralogous genes underwent fragment duplication and whole genome duplication events,respectively.SUS members in subfamily SUSⅢexpanded and were preserved some function,which undergone purified selection during evolution.Expression analysis showed that all SPS gene members and four SUS genes were significantly different expressed in'Hongyang'and'White'.The AchSUS7 gene was only detected expression in'Hongyang'.These genes may play important roles in the sugar accumulation and fruit quality of kiwifruit.