Table S5.xlsx from A new insight into the evolution and functional divergence of FRK genes in Pyrus bretschneideri

In plants, plant fructokinases (FRKs) are considered to be the main gateway of fructose metabolism as they can phosphorylate fructose to fructose-6-phosphate. Chinese white pears are one of the popular fruits in the world market; sugar content is an important factor affecting the quality of the fruit. We identified 49 FRKs from four Rosaceae species; 20 of these sequences were from Chinese white pear. Subsequently, phylogenic relationship, gene structure and micro-collinearity were analysed. Phylogenetic and exon–intron analysis classified these FRKs into 10 subfamilies, and was aimed further to reveal the variation of the gene structure and the evolutionary relationship of this gene family. Remarkably, gene expression patterns in different tissues or different development stages of the pear fruit suggested functional redundancy for PbFRKs derived from segmental duplication or genome-wide duplication and sub-functionalization for some of them. Additionally, PbFRK11, PbFRK13 and PbFRK16 were found to play important roles in regulating the sugar content in the fruit. Overall, this study provided important insights into the evolution of the FRK gene family in four Rosaceae species, and highlighted its roles in both pear tissues and fruits. Results presented here provide the appropriate candidate of PbFRKs that might contribute to fructose efflux in the pear fruit.

在植物中，果糖激酶（fructokinase, FRKs）被认为是果糖代谢的核心入口，其可将果糖磷酸化生成果糖-6-磷酸。中国白梨是全球市场广受欢迎的果品之一，而糖分含量是影响果实品质的关键因素。本研究从4个蔷薇科（Rosaceae）物种中鉴定出49个FRK家族成员，其中20个序列来自中国白梨。随后，我们对这些基因的系统发育关系、基因结构及微观共线性展开了分析。通过系统发育与外显子-内含子结构分析，可将这些FRKs划分为10个亚家族，本分析旨在进一步揭示该基因家族的基因结构变异与进化关系。值得注意的是，对梨果实不同组织及不同发育阶段的基因表达模式分析显示，由片段复制或全基因组复制产生的PbFRKs存在功能冗余现象，而部分PbFRKs则发生了亚功能化。此外，研究发现PbFRK11、PbFRK13与PbFRK16在调控梨果实糖分含量方面发挥着重要作用。综上，本研究为4个蔷薇科物种中FRK基因家族的进化研究提供了重要见解，并阐明了该基因家族在梨组织与果实中的功能作用。本研究结果可为鉴定参与梨果实果糖转运的PbFRKs候选基因提供重要参考。