独脚金内酯类似物GR24对山定子幼苗低氮胁迫的缓解作用  

Alleviation effect of GR24,a strigolactone analogue,on low-nitrogen stress in Malus baccata seedlings

作　　者：张鑫 马迎杰 齐边斌 于波 吕德国 秦嗣军 ZHANG Xin;MA Yingjie;QI Bianbin;YU Bo;LYU Deguo;QIN Sijun(College of Horticulture,Shenyang Agricultural University/Key Laboratory of Fruit Quality Development and Regulation of Liaoning Province,Shenyang 110866,China;Publishing Department of Shenyang Agricultural University,Shenyang 110866,China)

机构地区：[1]沈阳农业大学园艺学院/辽宁省果树品质发育与调控重点实验室,沈阳110866 [2]沈阳农业大学出版部,沈阳110866

出　　处：《应用生态学报》2023年第6期1592-1600,共9页Chinese Journal of Applied Ecology

基　　金：财政部和农业农村部国家现代农业产业技术体系(CARS-27);国家自然科学基金项目(31972359);辽宁省农业攻关及产业化项目(2020JH2/10200028)资助。

摘　　要：研究叶面喷施不同浓度独脚金内酯类似物GR24(0、1、5、10、20μmol·L^(-1))对低氮胁迫下山定子幼苗叶片光合生理特性及根系活性氧代谢和氮同化的影响,以期探索应用GR24缓解山定子幼苗低氮胁迫的适宜方法。结果表明:低氮胁迫下山定子幼苗地上部生物量显著降低,根冠比升高;叶片中叶绿素含量降低,类胡萝卜素含量升高,光合活性降低;根系中超氧化物歧化酶和过氧化氢酶活性变化不显著,但过氧化物酶和抗坏血酸过氧化物酶活性及可溶性糖、游离脯氨酸和活性氧含量显著升高,可溶性蛋白含量显著降低;根系中硝酸根离子含量降低,铵根离子含量升高,硝酸还原酶和谷氨酸合成酶活性均降低。与不喷施GR24相比,低氮胁迫和正常供氮条件下叶面喷施10和20μmol·L^(-1)GR24处理都不同程度增加了山定子幼苗生物量和根冠比,提高了叶绿素含量,增强了净光合速率、蒸腾速率和气孔导度等光合参数,改善了PSⅡ最大光化学效率和单位面积电子传递量子产额等荧光特性,增加了根系渗透调节物质(可溶性蛋白、可溶性糖和游离脯氨酸)含量,增强了根系谷氨酰胺合成酶活性;低氮胁迫下叶面喷施10和20μmol·L^(-1)GR24处理还显著降低了根系活性氧和铵根离子含量,提高了根系抗氧化酶、硝酸还原酶和谷氨酰胺合成酶等氮代谢关键酶活性,增加了硝酸根离子含量。其中以10μmol·L^(-1)GR24处理对低氮胁迫下山定子幼苗的作用效果最好,在低氮土壤的果园有一定的应用前景。To investigate the efficacy of foliar application of GR24,a strigolactone analogue,in alleviating lownitrogen stress in Malus baccata,we applied GR24 with different concentrations(0,1,5,10,and 20μmol·L^(-1))to leaves of plants under low nitrogen stress.We evaluated the changes in photosynthetic characteristics of leaves,reactive oxygen metabolism,and nitrogen assimilation in roots.The results showed that shoot biomass of seedling significantly decreased and root-shoot ratio increased under low-nitrogen stress.The chlorophyll contents decreased,the carotenoid content increased,and the photosynthetic activity decreased.The activities of superoxide dismutase and catalase enzymes in roots changed little,while the activities of peroxidase and ascorbic acid peroxidase enzymes,along with the levels of soluble sugar,free proline,and reactive oxygen species showed a significant increase,and the soluble protein content decreased.The NO3-content in roots decreased,the NH4+content increased,while activities of nitrate reductase and glutamine synthase decreased.Compared to the control group without GR24 application,foliar sprays of 10 and 20μmol·L^(-1)GR24 under both normal and low-nitrogen increased biomass and root-shoot ratio to varying degrees.Additionally,GR24 application increased chlorophyll content,photosynthesis indices(net photosynthetic rate,transpiration rate and stomatal conductance),and fluorescence(maximum photochemical efficiency of PSⅡand quantum yield of electron transfer per unit area)performance parameters,as well as the contents of osmotic regulation substances(soluble protein,soluble sugar,and free proline)and glutamine synthase activity.Application of 10 and 20μmol·L^(-1)GR24 under low-nitrogen stress decreased carotenoid,reactive oxygen species,and NH4+contents,while increased the activities of antioxidases and key enzymes in nitrogen metabolism(nitrate reductase and glutamine synthase)and NO3-content.The 10μmol·L^(-1)GR24 treatment was the most effective in alleviating low nitrogen stress,wh

关 键 词：山定子 低氮胁迫 独脚金内酯 GR24 光合特性 活性氧代谢 

分 类 号：S661.1[农业科学—果树学]