黄瓜蔗糖代谢关键酶基因家族鉴定及表达分析

Identification and expression analysis of key sucrose metabolism enzyme gene family in cucumber

蔗糖合酶(SUS)、蔗糖磷酸合酶(SPS)和蔗糖转化酶(INV)是高等植物蔗糖代谢关键酶。为探究这三类蔗糖代谢关键酶基因家族在黄瓜果实糖含量与非生物胁迫中发挥的作用,本文对其基因家族成员的数量、进化关系、顺式作用元件、基因结构和表达模式进行分析。结果表明,黄瓜3类蔗糖代谢关键酶基因家族共有20个成员,SUS包含4个成员,SPS包括3个成员,INV包括13个成员,不均匀分布在6条染色体上;系统进化分析发现黄瓜3类蔗糖代谢关键酶基因家族成员与甜瓜亲缘关系最近;其启动子序列主要含有光响应、低温响应、激素响应和防御应激等顺式作用元件。基因表达谱分析发现CsCINV3在盐和硅胁迫中下调表达,CsSUS4在高糖四倍体黄瓜中显著上调表达。qRT-PCR验证显示,CsSUS4在高糖黄瓜中显著上调,与RNA-Seq趋势相一致。综上,CsSUS4可能与黄瓜果实糖含量及非生物胁迫有着密切的关系。

Sucrose synthase(SUS),sucrose phosphate synthase(SPS)and sucrose invertase(INV)are key sucrose metabolism enzymes in higher plants.To explore the roles of these three key sucrose metabolism enzyme gene families on the sugar content and abiotic stress,the number,evolutionary relationship,cis-regulatory element,gene structure and expression pattern of three key sucrose metabolism enzyme gene families were analyzed in cucumber(Cucumis sativus).The results showed that totally 20 members were identified in three key sucrose metabolism enzyme gene families in cucumber,among these,SUS contained 4 members,SPS contained 3 members and INV contained 13 members,distributing on 6 chromosomes.Phylogenetic analysis showed that the members of three key sucrose metabolism enzyme gene families in cucumber were closely related to melon,and their promoter sequences mainly contain cis-acting elements such as light response,low temperature response,hormone response and defense against stress.Gene expression profile analysis showed that CsCINV3 was down-regulated under salt and silicon stress,while CsSUS4 was significantly up-regulated in high-sugar tetraploid cucumber.qRT-PCR analysis showed that the relative expression of CsSUS4 in high-sugar fruits was up,which was consistent with the trend of RNA-Seq.In conclusion,CsSUS4 may be closely related to the fruit sugar content and abiotic stress in cucumber.