转酮醇酶基因沉默对高温胁迫下黄瓜幼苗光合作用的影响  

Effects of transketolase gene silencing on photosynthesis in cucumber seedlings under high temperature stress

作　　者：毕焕改[1] 李福德 董绪兵[1] 艾希珍[1] 

机构地区：[1]山东农业大学园艺科学与工程学院,作物生物学国家重点实验室,农业部黄淮地区园艺作物生物学与种质创制重点开放实验室,山东泰安271018

出　　处：《植物生理学报》2017年第10期1859-1866,共8页Plant Physiology Journal

基　　金：山东省自然科学基金(BS2015NY011);国家自然科学基金(31701909);山东省现代农业产业技术体系建设专项资金(SDAIT-05-10);“双一流”奖补资金(SYL2017YSTD06)~~

摘　　要：以2个反义转酮醇酶基因(CsTK)黄瓜株系T2′-2和T2′-4以及野生型黄瓜‘08-1’为试材,研究CsTK沉默对高温(40℃)下黄瓜幼苗净光合速率(P_n)、核酮糖-1,5-二磷酸羧化/加氧酶(Rubisco)活性及其mRNA表达量和叶绿素荧光参数的影响。结果表明,与野生型相比,2个反义株系的转酮醇酶(TK)活性和CsTK mRNA的表达量显著降低。高温胁迫2h后,黄瓜幼苗叶片的P_n、气孔导度(G_s)以及以吸收光能为基础的光化学性能指数(PI_(ABS))、Rubisco活性及其mRNA表达量和光系统(PSⅡ)活性均显著降低,而CsTK的mRNA表达量和TK活性及胞间CO_2(C_i)浓度明显升高,但2个反义株系各指标始终低于野生型植株,尤其‘T2′-4’最低。CsTK沉默加剧了高温条件下黄瓜幼苗Rubisco和PSⅡ活性的降低,从而导致转反义CsTK黄瓜幼苗的光合作用降低幅度较大,对高温耐性下降。The two anti-sense transketolase gene（CsTK） transgenic lines T2′-2 and T2′-4 as well as the wild type（WT） ‘08-1＇ cucumber seedlings were used as test materials to study the effect of CsTK silence on net photosynthetic rate（P_n）,the m RNA abundance and activity of ribulose bisphosphate carboxylic enzyme（Rubisco） as well as the chlorophyll fluorescence parameters of cucumber（Cucumis sativa） seedlings under high temperature（40℃） stress.The results showed that the m RNA abundance of CsTK and TK（transketolase） activity were significantly lower in CsTK suppress-expressing cucumber seedlings than those in WT.Following 2-h exposure to high temperature,we assayed a lower P_n,stomatal conductance（Gs）,photochemical performance index based on the absorption of light energy（PI_（ABS））,the mRNA abundance and activity of Rubisco as well as the activity of photosystem（PSⅡ）,while a higher CsTK m RNA abundance and TK activity and intercellular CO_2 concentration（C_i） in both antisense and WT plants.However,these parameters of the two anti-sense transgenic lines were always lower compared to the WT,especially,the parameters of T2′-4 was the lowest.In general,the data suggested that CsTK silence exacerbated the reduction of the activity of Rubisco and PSⅡ which led to the decrease of photosynthesis and high temperature tolerance in anti-sense CsTK transgenic cucumber seedlings.

关 键 词：CsTK 反义植株 高温 光合速率 黄瓜 

分 类 号：S642.2[农业科学—蔬菜学]