海巴戟果实软化相关基因McXTH的克隆和表达分析  

Cloning and Expression Analysis of McXTH Associated with Fruit Softening in Morinda citrifolia

作　　者：李佳莹 宫树森 秦英 金璨 吴田[1] LI Jiaying;GONG Shusen;QIN Ying;JIN Can;WU Tian(School of Landscape Architecture and Horticulture Sciences,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]西南林业大学园林园艺学院,昆明650224

出　　处：《四川农业大学学报》2024年第1期94-102,共9页Journal of Sichuan Agricultural University

基　　金：国家林业和草原局项目([2019]27)。

摘　　要：【目的】了解诺丽果实软化规律,克隆木葡聚糖内转糖苷酶/水解酶(XTH)基因,初步明确其表达模式。【方法】用果实硬度计测量后熟阶段的诺丽果实在25℃放置及乙烯利处理两种状态下的硬度变化。从诺丽果实采后0~48 h转录组数据中筛选差异表达的XTH候选基因。通过生物信息学分析,克隆目的基因全长,并利用荧光定量PCR技术分析基因表达模式,同时用便携式乙烯测量仪测定内源乙烯释放量。【结果】后熟阶段的海巴戟果实采后表皮硬度随贮藏时间增加而下降,且乙烯利处理后的软化趋势较室温自然放置更为显著。从海巴戟果实采后0~48 h转录组数据中筛选出基因XTH(DN16278g1)的表达量高、差异大。该基因具有完整的开放阅读框(ORF),克隆测序后将其命名为McXTH,并将其提交Genbank获得登录号为ON512442。McXTH基因ORF全长1062 bp,共编码353个氨基酸,与其他植物中的XTH基因氨基酸序列的相似性为75%~88%。RT-qPCR结果和内源乙烯释放量表明,在海巴戟果实成熟阶段McXTH的表达量与同时期的内源乙烯释放量在趋势上大体相同。【结论】海巴戟果实的软化受乙烯和关键基因XTH调控,Mc XTH的克隆为进一步进行XTH基因在海巴戟果实成熟软化过程的功能研究夯实基础。【Objective】This study is to find out the law of noni softening and to clone noni XTH gene and preliminarily clarify its expression pattern.【Method】In this study,a fruit firmness tester was used to investigate the firmness change of noni fruits in the post-ripening stage under the nature state of room temperature and condition of ethylene treatment.The differentially expressed gene XTH,was screened out from the transcriptome data of noni fruits that were picked after 0~48 h.The full length of XTH was isolated after bioinformatics analysis.The expression was further analyzed using RT-qPCR.The ethylene release amount was investigated using portable ethylene measuring instrument.【Result】The hardness of the postharvest skin of M.citrifolia in the late ripening stage decreases with increasing storage time.And the softening trend of after ethylene treatment is more significant than when placed naturally at room temperature.The gene XTH(DN16278g1)showing high and largely differential expression was identified from the transcriptome data of M.citrifolia fruits that were picked after 0~48 h.This gene has a complete open reading frame(ORF).It was named as McXTH after clon and sequencing.The sequence of this gene was further submitted to Genebank and the accession number is ON512442.McXTH is 1062 bp in length encoding 353 amino acids showing 75%~88%of sequence similarity with other plants.RT-qPCR results and endogenous ethylene release amount analysis showed that the endogenous ethylene release trend of M.citrifolia fruits is consistent with the expression of McXTH in the same period.【Conclusion】Ethylene and McXTH take part in regulating fruit softening of M.citrifolia.The cloning of McXTH provides a basis for studying its function in the ripening and softening process of M.citrifolia.

关 键 词：海巴戟 木葡聚糖内转糖苷酶/水解酶(XTH) 果实软化 果实成熟 乙烯 

分 类 号：S667.9[农业科学—果树学]