掌叶覆盆子多聚半乳糖醛酸酶基因家族鉴定及在果实发育中的作用  

Genome-wide identification of the polygalacturonase gene family in Rubus chingii and its roles in fruit development

作　　者：沈丹维 朱婷 李妹新 江景勇 时羽杰 李小白[3] 曾为 陈珍 SHEN Danwei;ZHU Ting;LI Meixin;JIANG Jingyong;SHI Yujie;LI Xiaobai;ZENG Wei;CHEN Zhen(School of Life Sciences/Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation,Taizhou University,Taizhou 318000,Zhejiang,China;Institute of Horticulture,Taizhou Academy of Agricultural Sciences,Taizhou 318000,Zhejiang,China;Institute of Horticulture,Zhejiang Academy of Agricultral Sciences,Hangzhou 310021,Zhejiang,China)

机构地区：[1]台州学院生命科学学院/浙江省植物进化生态学与保护重点实验室,浙江台州318000 [2]台州市农业科学院园艺研究所,浙江台州318000 [3]浙江省农业科学院园艺研究所,浙江杭州310021

出　　处：《浙江农林大学学报》2025年第2期249-260,共12页Journal of Zhejiang A&F University

基　　金：浙江省基础公益研究计划项目(LGN22C020001);台州市科技计划项目(21nya14)。

摘　　要：【目的】对掌叶覆盆子Rubus chingii果胶水解酶中的多聚半乳糖醛酸酶(polygalacturonase,PG)基因家族进行鉴定与分析,找出果实发育过程中的关键编码基因PGs,可为实现药果果型大或红果花托软的育种目标提供理论参考。【方法】基于掌叶覆盆子基因组,利用生物信息学方法筛选和鉴定掌叶覆盆子PG基因家族成员,并利用转录组测序和实时荧光定量PCR(RT-qPCR)进行表达模式分析。【结果】共鉴定了47个覆盆子RchPGs基因,不均匀地分布在7条染色体上,根据系统发育可分为6个分支(Clade A~D)。其中28个RchPGs蛋白都具有完整的4个结构域Ⅰ(SPNTDG)、Ⅱ(GDDC)、Ⅲ(CGPGHGISIGSLG)和Ⅳ(RIK);11个RchPGs蛋白不包含结构域Ⅲ。转录组测序结果表明:RchPG6、RchPG29、RchPG1、RchPG23和RchPG12等在果实发育早期起作用,参与果实膨大过程中的细胞壁水解;而RchPG16、RchPG2、RchPG10、RchPG28和RchPG38等则在果实发育后期表达量升高,介导果实成熟与软化。尤其是RchPG16,红果期表达量急剧升高,每千个碱基/百万个定位片段(FPKM)是未成熟大绿(BGⅠ)时期的2168.17倍,说明RchPG16对果实成熟与软化具有至关重要的作用。【结论】RchPG基因家族成员在掌叶覆盆子果实发育不同阶段差异表达,分别促进果实膨大和软化,其中RchPG16和RchPG28在果实成熟软化过程中可能起到关键作用。[Objective]The polygalacturonase(PG)gene family members of pectin hydrolase in Rubus chingii were identified and analyzed in this study,and the vital PG-coding genes during fruit development were screened,which could provide a theoretical reference for achieving the breeding goals to expand the fruit size or inprove fruit softening.[Method]Genome-wide identification and bioinformatics methods were used to identify the PG gene family members of R.chingii.Transcriptome sequencing and RT-qPCR were used to analyze expression patterns of PG genes during fruit developmental stages.[Result]A total of 47 RchPGs were predicted,which were unevenly distributed on 7 chromosomes.Phylogenetic relationships showed they could be divided into 6 clades(Clade A-D).Among these,28 RchPGs proteins had integrated 4 domains,Ⅰ(SPNTDG),Ⅱ(GDDC),Ⅲ(CGPGHGISIGSLG),andⅣ(RIK),while 11 RchPGs missed domainⅢ.The result of the transcriptome sequencing showed that RchPG6,RchPG29,RchPG1,RchPG23 and RchPG12 involved in hydrolysis of cell wall for fruit expansion at earlier stages of fruit development.Oppositely,RchPG16,RchPG2,RchPG10 and RchPG38 were highly expressed at later stages and might be essential for fruit ripening and softening.In particular,the expression level(FPKM values from RNA-seq)of RchPG16 was dramatically increased at the red fruit stage,and the FPKM value was 2168.17 times higher than that at the immature big green(BGⅠ)stage,indicating that it played a significant role in fruit ripening and softening.[Conclusion]RchPG gene family in R.chingii were differentially expressed in different stages of fruit development to improve fruit expansion and softening.Among them,RchPG16 and RchPG28 genes may play a key role in the ripening and softening of R.chingii.

关 键 词：多聚半乳糖醛酸酶 掌叶覆盆子 果实膨大 成熟软化 生物信息学 

分 类 号：S567[农业科学—中草药栽培]