外源褪黑素对养分胁迫下苹果砧木幼苗氮代谢相关酶活性及基因表达的影响  

Effects of exogenous melatonin on nitrogen metabolism related enzyme activities and genes expression in apple rootstock seedlings under nutrient stress

作　　者：刘怀特 曹扬 杜培华 周莎莎 李中勇[1] 张学英[1] 徐继忠[1] 梁博文 LIU Huai-te;CAO Yang;DU Pei-hua;ZHOU Sha-sha;LI Zhong-yong;ZHANG Xue-ying;XU Ji-zhong;LIANG Bo-wen(College of Horticulture,Hebei Agricultural University,Baoding,Hebei 071001,China)

机构地区：[1]河北农业大学园艺学院,河北保定071001

出　　处：《植物营养与肥料学报》2023年第10期1884-1895,共12页Journal of Plant Nutrition and Fertilizers

基　　金：河北省自然科学基金(C2021204158);河北省在读研究生创新能力培养资助项目(CXZZBS2023071);河北省属高校基本科研业务费(KY2021054);河北农业大学人才引进科研专项(YJ201904);国家现代农业产业技术体系资助项目(CARS-27)。

摘　　要：【目的】探究外源褪黑素对养分胁迫下苹果砧木幼苗内源褪黑素合成、氮代谢关键酶活性及氮代谢和氮转运相关基因表达的影响。【方法】水培试验材料为7~8片叶的平邑甜茶(Malus hupehensis Rehd.)幼苗。幼苗在1/2 Hoagland营养液中生长12天,然后分为两组,一组营养液中添加褪黑素(0.1μmol/L),一组不添加作为对照。第15天时,两组幼苗的营养液浓度又分为1/2和1/20 Hoagland营养液两个养分水平,形成4个处理:1/2 Hoagland营养液(CK)、1/2 Hoagland营养液+0.1μmol/L褪黑素(MCK)、1/20 Hoagland营养液(ST)、1/20 Hoagland营养液+0.1μmol/L褪黑素(MST)。第35天时(处理20天),取平邑甜茶幼苗叶片和根系样品,测定褪黑素含量、氮代谢相关酶活性、褪黑素合成关键酶和氮转运代谢相关基因的相对表达量。【结果】与CK相比,养分胁迫(ST)上调了平邑甜茶幼苗叶片中褪黑素合成相关基因MdTDC、MdT5H、MdAANAT和MdASMT的表达,显著增加了内源褪黑素含量,降低了幼苗叶片及根中的硝酸还原酶(NR)、亚硝酸还原酶(NiR)、谷氨酰胺合成酶(GS)、Fd-谷氨酸合成酶(Fd-GOGAT)和NADH-谷氨酸合成酶(NADH-GOGAT)活性(P<0.05),下调了5个氮代谢相关基因NR、NiR、GS、Fd-GOGAT和NADH-GOGAT的表达量,但上调了叶片中氮转运基因MdNRT1.1、MdNRT2.5、MdNRT2.7、MdAMT1.2、MdAMT1.5和MdAMT2.1的表达量。与ST相比,MST处理苹果幼苗叶片中4个褪黑素合成基因的表达上调,内源褪黑素含量显著升高了3.10%(P<0.05),叶片中NR、NiR、GS和Fd-GOGAT活性分别升高65.62%、51.49%、59.63%和17.53%,根系中NiR、GS和Fd-GOGAT活性分别显著升高19.52%、52.09%和12.72%;叶片中5个氮代谢相关基因NR、NiR、GS、Fd-GOGAT和NADH-GOGAT的表达水平显著升高至ST处理的2.16、2.08、2.22、1.71和1.19倍,根系中4个氮代谢相关基因NiR、GS、Fd-GOGAT和NADH-GOGAT表达水平升高至ST处理的1.31、1.41、1.74和1.54倍,并显著上调了苹果幼苗叶片中【Objectives】The aim of the research was to investigate the effects of exogenous melatonin on endogenous melatonin synthesis,nitrogen metabolism key enzyme activities,nitrogen metabolism,and nitrogen transport gene expression in apple rootstock seedlings under nutrient stress.【Methods】In this experiment,Malus hupehensis Rehd.seedlings were used as experimental materials for hydroponic experiments.M.hupehensis seedlings with 7−8 leaves were firstly cultured in 1/2 Hoagland nutrient solution for 12 days.Then the seedlings were divided into two groups,one group was added wtih 0.1μmol/L melatonin in the nutrient solution and the other group wa not,and continued to grow for another 3 days.Each group was then further divided into two groups,one was supplied with 1/2 Hoagland nutrient solution,and the other was supplied with 1/20 Hoagland nutrient solution(nutrient stress),forming 4 treatments,as:1/2 Hoagland nutrient solution(CK),1/2 Hoagland nutrient solution+0.1μmol/L melatonin(MCK),1/20 Hoagland nutrient solution(ST),1/20 Hoagland nutrient solution+0.1μmol/L melatonin(MST).After 20 days of treatment,the leaf and root samples were collected for the measurement of melatonin content,nitrogen metabolism-related enzyme activities,melatonin synthesis enzymes,and N transport/metabolism related gene expression levels.【Results】Compare with CK,ST treatment upregulated the expression of melatonin synthesis-related genes MdTDC,MdT5H,MdAANAT and MdASMT in the leaves of M.hupehensis seedlings,and increased the endogenous melatonin content(P<0.05),decreased the activities of nitrate reductase(NR),nitrite reductase(NiR),glutamine synthetase(GS),Fd-glutamate synthetase(Fd-GOGAT)and NADH-glutamate synthetase(NADH-GOGAT)in the leaves and roots of M.hupehensis seedlings(P<0.05),and down-regulated the expression levels of nitrogen metabolism related genes NR,NiR,GS,Fd-GOGAT and NADH-GOGAT,while up-regulated the expression levels of nitrogen transport genes MdNRT1.1,MdNRT2.5,MdNRT2.7,MdAMT1.2,MdAMT1.5,and MdAMT2.1 in leav

关 键 词：养分胁迫 平邑甜茶 褪黑素 氮代谢 基因表达 

分 类 号：S661.1[农业科学—果树学]