温州蜜柑与椪柑果实日灼发生差异及机制  

Differences in Occurrence of Fruit Sunburn Between Satsuma Mandarin and Ponkan Tangerine and Possible Mechanisms

作　　者：吴卓群 陈鹏旭 陈思怡 张福琼 方红 祝建 谢宗周[1] 李春龙 刘继红[1] WU Zhuoqun;CHEN Pengxu;CHEN Siyi;ZHANG Fuqiong;FANG Hong;ZHU Jian;XIE Zongzhou;LI Chunlong;LIU Jihong(National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops,College of Horticulture and Forestry,Huazhong Agricultural University,Wuhan 430070,China;Special Products Technology Promotion Center of Dangyang City,Dangyang,Hubei 444100,China)

机构地区：[1]华中农业大学园艺林学学院,果蔬园艺作物种质创新与利用全国重点实验室,武汉430070 [2]湖北省当阳市特产技术推广中心,湖北当阳444100

出　　处：《园艺学报》2024年第12期2743-2757,共15页Acta Horticulturae Sinica

基　　金：湖北重点研发专项(2022BBA0073);湖北洪山实验室重大项目(2021hszd009);华中农业大学荆楚行项目。

摘　　要：日灼是柑橘生产中常见的生理障碍,但其形成机制不清晰。2021年在湖北省当阳市半月镇凤凰山,以温州蜜柑和椪柑果实为试材,通过日灼果皮受伤程度对比、细胞形态学观察以及抗氧化物质含量和基因表达量差异等多角度综合比较二者的日灼差异并分析可能机制。结果表明,温州蜜柑(日灼发生率43.12%)比椪柑(22.52%)更易遭受日灼伤害;日灼对于温州蜜柑果皮细胞紧密度造成严重影响的同时还造成木质素的积累,并积累更多的活性氧。聚甲氧基黄酮途径中的代谢物川皮苷在椪柑日灼伤害过程中显著富集。类黄酮代谢中关键酶基因CrCHS2、CrCHI和CrFNS以及聚甲氧基黄酮合成关键基因CrOMT2在椪柑日灼果皮中均显著上调,并且表达水平显著高于相同日灼等级的温州蜜柑。上述结果表明,温州蜜柑和椪柑果实产生日灼差异的主要原因是椪柑含有更多抗氧化物质,能够更有效地减少活性氧积累,从而减弱日灼造成的伤害。Sunburn is a common physiological disorder in citrus production,but the underlying mechanism remains largely unknown.The study was carried out at Fenghuang Mountain,Banyue Town,Dangyang City,Hubei Province in 2021.Satsuma mandarin(Citrus unshiu Marc.)and Ponkan(C.reticulata)were used as experimental materials to investigate the difference in sunburn and potential mechanisms by examining peel injury degree,performing cytological observation,measuring antioxidant content and gene expression levels.The results showed that Satsuma mandarin was more susceptible to sunburn than Ponkan.Significant difference in the incidence rates of sunburn was observed between the two varieties,43.12%for Satsuma mandarin and 22.52%for Ponkan.Sunburn seriously influenced the compactness of pericarp cells and resulted in the accumulation of lignin.Satsuma mandarin fruits were found to accumulate greater level of reactive oxygen species(ROS).In addition,nobiletin,a critical metabolite in the polymethoxyflavone metabolic pathway,was significantly enriched in Ponkan fruit peel.Consistently,transcript levels of CrCHS2,CrCHI and CrFNS,encoding crucial enzymes involved in biosynthesis of flavonoid,and CrOMT2 in the polymethoxyflavone pathway were significantly induced in the sunburnned Ponkan fruit peel.Taken together,these findings indicate that the main reason for the difference in sunburn between Satsuma mandarin and Ponkan is that the latter contains more antioxidant that can effectively decrease the ROS accumulation,thus leading to mitigation of sunburn-derived damage.

关 键 词：柑橘 日灼 黄酮 黄酮醇 代谢途径 聚甲氧基黄酮 

分 类 号：S666.1[农业科学—果树学]