与质外体活性氧产生相关的酶基因在库尔勒香梨果实不同发育时期的表达特性  

Expression characteristics of apoplastic ROS-related-enzyme genes at different development stages of Kuerlexiangli pear

作　　者：史智勇 曹艺洁 玉苏甫·阿不力提甫[2] 艾沙江·买买提[1] SHI Zhiyong;CAO Yijie;Yusuf·Ablitif;Aisajan·Mamat(Institute of Horticultural Crops,Xinjiang Academy of Agricultural Sciences,Urumqi 830091,Xinjiang,China;College of Forestry and Horticulture,Xinjiang Agricultural University,Urumqi 830052,Xinjiang,China)

机构地区：[1]新疆农业科学院园艺作物研究所,乌鲁木齐830091 [2]新疆农业大学林学与园艺学院,乌鲁木齐830052

出　　处：《果树学报》2021年第11期1829-1838,共10页Journal of Fruit Science

基　　金：新疆维吾尔自治区自然科学基金(2019D01A63);新疆维吾尔自治区园艺重点学科(2016-10758-3);新疆农业大学特色林果果实发育与调控创新团队。

摘　　要：【目的】探讨库尔勒香梨(Pyrus sinkiangensis Yü)果实不同发育时期石细胞的形成与质外体活性氧产生之间可能存在的关系,为调控库尔勒香梨果实石细胞含量、改善果实品质提供科学依据。【方法】以15年生库尔勒香梨为试材,利用显微镜观察果肉中石细胞发育特征,通过实时荧光定量PCR分析与活性氧产生相关的酶基因的相对表达量,探讨质外体活性氧在库尔勒香梨果实石细胞分化过程中的作用。【结果】库尔勒香梨石细胞染色结果表明,在果实发育过程中石细胞相对含量呈先上升后下降趋势,在花后10~30 d呈上升趋势。该时期果实中石细胞处于初步分化和形成阶段,数量最多,相对分散,部分细胞没有或者不完全被染色,其中心部位染色面积慢慢加深;花后60 d石细胞相对含量(单位面积)随着薄壁细胞的膨大迅速下降;花后80~100 d石细胞相对含量趋于稳定。实时荧光定量PCR结果表明,与质外体活性氧产生相关的酶基因的表达趋势与石细胞的变化趋势大致相同,编码与质外体活性氧产生相关的呼吸暴发氧化酶同源物蛋白D(RBOHD)、超氧化物歧化酶(SOD)、具有草酸氧化酶活性的类萌发素蛋白(GLP)、脂氧合酶(LOX、LOX5)及多胺氧化酶(PAO1、PAO 5-like)等酶基因也是在果实发育早期高表达。随着果实的发育,这些酶基因的表达量逐渐下降,并在花后80~100 d其表达水平趋于较低水平且保持稳定。这些基因最高表达水平和最低表达水平之间的差异倍数在5~157倍之间。【结论】花后10~60 d是库尔勒香梨果实石细胞形成的关键时期,该时期同样是与质外体活性氧产生相关的酶基因高水平表达时期,说明石细胞分化和质外体活性氧积累之间存在协同关系。【Objective】Kuerlexiangli pear(Pyrus sinkiangensis Yü)is a cultivar selected from a hybrid pear species of Xinjiang Autonomous Region in China.Kuerlexiangli pear is distinctive for its aroma,rich juicy flesh and crispy texture.However,recently the formation of rough skin fruits has been one of the major factors that adversely affect fruit quality,and increasing stone cell content is the typical phenotype of rough skin fruits.Stones cells are dead ones derived from parenchyma cells and mainly composed of cellulose,hemicellulose and lignin.The formation of stone cells is closely related to reactive oxygen species(ROS)in plasma membrane,especially for apoplastic H_(2)O_(2).Apoplastic H_(2)O_(2) serving as an oxidant,plays important roles in oxidative coupling of lignin monomers,and cross-linking between cell wall polymers by diferulic linkages.In addition,H_(2)O_(2) can also promote the process of programmed cell death(PCD).Since the polymerization of lignin is carried out on the cell wall,in this experiment,we tried to explore the possible relationship between the formation of stone cells and the apoplastic ROS production in Kuerlexiangli pear by analyzing the expression patterns of genes encoding,respirato-ry burst oxidase homologue D(RBOHD),superoxide dismutase(SOD),lipoxygenase(LOX),germin like protein(GLP)with oxalate oxidase activity and polyamine oxidase(PAO)that were related to apo-plasic ROS production,so as to provide a scientific basis for regulating the content of stone cells in'Ko-rla Fragrant Pear'fruit and improving fruit quality.【Methods】15 years old Kuerlexiangli pear trees were used as the plant materials to study the possible roles of apoplastic ROS during the formation of stone cells.Stone cell staining and relative expression levels of apoplastic ROS generating genes were then performed on fruit samples that were collected at five different developmental stages(10,30,60,80 and 100 days after flowering,DAF),representing the prime stage(10-30 DAF),late(60 DAF)and sta-tionary stage(80-100 D

关 键 词：库尔勒香梨 果实发育 石细胞 质外体活性氧 基因表达 

分 类 号：S661.2[农业科学—果树学]