Genome-wide identification, molecular evolution, and functional characterization of fructokinase gene family in apple reveal its role in improving salinity tolerance    

苹果果糖激酶基因家族的全基因组鉴定、分子进化和功能特征揭示了它们在提高盐胁迫耐受性中的作用

Jing Su1*, Lingcheng Zhu2*, Pingxing Ao1, Jianhui Shao3, Chunhua Ma1#

1 College of Landscape and Horticulture, Yunnan Agricultural University, Kunming, 650201, Yunnan, China.

2 State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Shaanxi Key Laboratory of Apple, Northwest A&F University, Yangling, 712100, Shaanxi, China

3 College of Plant protection, Yunnan Agricultural University, Kunming, 650201, Yunnan, China

摘要  

果糖激酶(FRK)是植物体内果糖信号转导的调节因子，其通过磷酸化催化果糖代谢。课题组前期研究表明MdFRK2蛋白不仅对果糖具有高亲和力，而且对山梨醇具有较高催化活性。然而，苹果FRK基因家族的全基因组鉴定及其演化进程尚未报道。本研究通过系统的全基因组分析，共鉴定了9个苹果FRK基因成员，在系统发育上将其分为七个聚类。MdFRK基因的染色体定位和共线性分析揭示，它们在苹果基因组中的扩张主要受串联和染色体片段复制事件的驱动。在4个源库组织和5个不同苹果果实发育阶段观察到MdFRKs的差异表达，这表明它们在苹果果实发育和糖积累中可能起着至关重要的作用。RT-qPCR鉴定了对盐和干旱胁迫敏感的MdFRK候选基因，其中过表达MdFRK2转基因苹果植株显著增强了耐盐性。总之，本研究结果对于了解MdFRKs在调控苹果果实发育和耐盐应答中的功能具有重要的意义。

Abstract  

Fructokinase (FRK) is a regulator of fructose signaling in plants and gateway proteins that catalyze the initial step in fructose metabolism through phosphorylation.  Our previous study demonstrated that MdFRK2 protein exhibit not only high affinity for fructose, but also high enzymatic activity due to sorbitol.  However, genome-wide identification of the MdFRK gene family and their evolutionary dynamics in apple are yet to be reported.  A systematic genome-wide analysis in this study identified a total of nine MdFRK gene members, which could phylogenetically be clustered into seven groups.  Chromosomal location and synteny analysis of MdFRKs revealed that their expansion in the apple genome is primarily driven by tandem and segmental duplication events.  Divergent expression patterns of MdFRKs were observed in four source-sink tissues and at five different apple fruit developmental stages, which suggested their potential crucial roles in the apple fruit development and sugar accumulation.  Reverse transcription-quantitative PCR (RT-qPCR) identified candidate NaCl or drought stress responsive MdFRKs, and transgenic apple plants overexpressing MdFRK2 exhibited considerably enhanced salinity tolerance.  Our results will be useful for understanding the functions of MdFRKs in the regulation of apple fruit development and salt stress response.

全文链接：https://www.sciencedirect.com/science/article/pii/S2095311924003228

Journal of Integrative Agriculture (《农业科学学报》(英文), JIA) 由中华人民共和国农业农村部主管，中国农业科学院与中国农学会主办，中国农业科学院农业信息研究所承办。综合性英文学术期刊，月刊。创刊于2002年，现任主编为中国科学院院士陈化兰。JIA主要栏目有作物科学、园艺、植物保护、动物科学、动物医学、农业生态环境、食品科学、农业经济与管理等。刊稿类型有综述、研究论文、简报以及评述等。全部论文在Elsevier-ScienceDirect (SD) 平台OA出版。最新SCI影响因子4.6，位于SCI-JCR农业综合学科Q1区。中国科学院分区农林科学1区。2016年以来先后获得中国科协等部委 “提升计划”“登峰计划”“卓越计划”项目支持。