甘蓝型油菜蔗糖磷酸合酶(SPS)基因家族成员鉴定及表达分析

蔗糖磷酸合酶(sucrose phosphate synthase, SPS)是调控植物蔗糖合成的限速酶, 对光合产物的转运和积累有重要影响。利用拟南芥SPS蛋白保守结构域在甘蓝型油菜基因组数据库鉴定出11个甘蓝型油菜SPS基因家族成员, 根据系统进化分析将其分成A、B和C共3个亚家族。基因结构预测表明, SPSC-1有5个外显子, 其他SPS基因均有11~15个外显子。顺式作用元件分析表明, 油菜SPS基因除含基本的启动子保守元件外, 还含有许多与逆境和激素响应相关的顺式作用元件。实时荧光定量PCR结果表明, BnSPSA1在花中表达量最高, BnSPSA2在各组织中均有不同程度的表达, BnSPSB只在叶、蕾和花中表达, BnSPSC在叶中表达量最高, 在蕾和花中有少量表达而在其他组织中基本不表达, 说明SPS基因在甘蓝型油菜中的表达具有明显的组织特异性; BnSPSA1和BnSPSC在高生物产量油菜叶片中的表达高于低生物产量油菜, BnSPSB则在低生物产量油菜中的表达量更高, 说明SPS基因与油菜生物产量密切相关。本研究为油菜SPS基因的功能研究和利用奠定了基础。

Genome-wide Analysis and Expression Profiling of SPS Gene Family in Brassica nupus L.

Sucrose phosphate synthase (SPS) is the rate-limiting enzyme that controls the sucrose biosynthesis in plants and has great influence on transportation and accumulation of photosynthate. In this study, we identified 11 members of the SPS gene family in the oilseed rape (Brassica nupus L.) genome. These SPS genes were classed into clusters A, B, and C according to gene structure and phylogenetic relationship. Gene structure prediction indicated that BnSPS genes were highly conserved, in which BnSPSC-1 consisted five exons and others consisted 11-15 exons. Promoter cis-element analysis indicated that BnSPS genes had not only essential responsive elements but also some types of elements potentially responsive to stresses or hormone responses. The qRT-PCR assay showed tissue-specific expressions of BnSPS genes with rich expressions of BnSPSA1 in flower, BnSPSB in leaf, bud and flower, BnSPSC in leaf, and BnSPSA2 in various tissues. The relative expression levels of BnSPSA1 and BnSPSC were higher in high-biomass rapeseed varieties than in low-biomass rapeseed varieties, whereas, that of BnSPSB was higher in low-biomass rapeseed varieties, suggesting that SPS genes are closely ralated to biological yield of rapeseed. This study provides basic information for functional study and utilization of BnSPS genes.