Sucrose synthases(SUS) are a family of enzymes that play pivotal roles in carbon partitioning, sink strength and plant development. A total of 11 SUS genes have been identified in the genome of Malus domestica(Md SUSs...Sucrose synthases(SUS) are a family of enzymes that play pivotal roles in carbon partitioning, sink strength and plant development. A total of 11 SUS genes have been identified in the genome of Malus domestica(Md SUSs), and phylogenetic analysis revealed that the Md SUS genes were divided into three groups, named as SUS I, SUS II and SUS III, respectively. The SUS I and SUS III groups included four homologs each, whereas the SUS II group contained three homologs. SUS genes in the same group showed similar structural characteristics, such as exon number, size and length distribution. After assessing four different tissues, Md SUS1 s and Md SUS2.1 showed the highest expression in fruit, whereas Md SUS2.2/2.3 and Md SUS3 s exhibit the highest expression in shoot tips. Most Md SUSs showed decreased expression during fruit development, similar to SUS enzyme activity, but both Md SUS2.1 and Md SUS1.4 displayed opposite expression profiles. These results suggest that different Md SUS genes might play distinct roles in the sink-source sugar cycle and sugar utilization in apple sink tissues.展开更多
基金supported in part by the National Natural Science Foundation of China (31372038)the Natural Basic Research Plan in Shaanxi Province of China (2015JQ3082)
文摘Sucrose synthases(SUS) are a family of enzymes that play pivotal roles in carbon partitioning, sink strength and plant development. A total of 11 SUS genes have been identified in the genome of Malus domestica(Md SUSs), and phylogenetic analysis revealed that the Md SUS genes were divided into three groups, named as SUS I, SUS II and SUS III, respectively. The SUS I and SUS III groups included four homologs each, whereas the SUS II group contained three homologs. SUS genes in the same group showed similar structural characteristics, such as exon number, size and length distribution. After assessing four different tissues, Md SUS1 s and Md SUS2.1 showed the highest expression in fruit, whereas Md SUS2.2/2.3 and Md SUS3 s exhibit the highest expression in shoot tips. Most Md SUSs showed decreased expression during fruit development, similar to SUS enzyme activity, but both Md SUS2.1 and Md SUS1.4 displayed opposite expression profiles. These results suggest that different Md SUS genes might play distinct roles in the sink-source sugar cycle and sugar utilization in apple sink tissues.
