外源褪黑素对高温胁迫下菊花光合和生理特性的影响  

Effects of exogenous melatonin on photosynthesis and physiological characteristics of chrysanthemum seedlings under high temperature stress

作　　者：齐晓媛 王文莉[1] 胡少卿 刘梦雨 郑成淑[1] 孙宪芝[1] QI Xiao-yuan;WANG Wen-li;HU Shao-qing;LIU Meng-yu;ZHENG Cheng-shu;SUN Xian-zhi(College of Horticultural Science and Engineering,Shandong Agricultural University/State Key Laboratory of Crop Biology,Tai'an 271018,Shandong,China)

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,山东泰安271018

出　　处：《应用生态学报》2021年第7期2496-2504,共9页Chinese Journal of Applied Ecology

基　　金：国家重点研发计划项目(2019YFD1001505);山东省林业科技创新项目(LYCX06-2018-33)资助。

摘　　要：以切花菊品种‘神马’为试材,研究外源褪黑素(MT)对菊花抗高温胁迫的影响。将供试菊花叶面喷施200μmol·L^(-1)的MT后,进行40℃(昼)/35℃(夜)高温胁迫,观察菊花叶片叶绿体和内囊体超微结构,测定光合和生理指标。结果表明:与常温对照(CK)相比,高温胁迫下菊花叶片叶绿体和类囊体受损,叶绿素含量和最大荧光(Fm)显著降低,OJIP曲线发生变化,K点和J点荧光升高,净光合速率(P_(n))、蒸腾速率(T_(r))、气孔导度(g_(s))均显著降低,胞间CO_(2)浓度(C_(i))均显著增加;相对电导率(REC)、丙二醛(MDA)、活性氧(ROS)、渗透调节物质含量和抗氧化酶活性显著增加。外源喷施MT可维持高温胁迫下植株叶绿体和类囊体结构的完整性,明显降低OJIP曲线中K点和J点上升的幅度,Fm、P_(n)、g_(s)、T_(r)和光合色素含量显著提高,C_(i)显著下降,缓解了高温胁迫对菊花光合和荧光作用的抑制。同时,外源喷施MT处理显著降低了高温胁迫下菊花REC、MDA和ROS含量,增强了菊花叶片中渗透调节物质含量和抗氧化酶活性。可见,外源MT可通过保护菊花叶片叶绿体结构的完整性,增强光合作用,抑制高温胁迫下菊花植株体内ROS的过度产生,提高抗氧化酶系统的活性,降低膜质过氧化水平和保护脂膜的完整性,从而提高菊花植株抗高温胁迫能力。We examined the effects of exogenous melatonin(MT)on the resistance of Chrysanthemum morifolium‘Jinba’to high temperature stress.Chrysanthemum leaves were sprayed with 200μmol·L^(-1)MT,and then subjected to high temperature stress at 40℃(day)/35℃(night).The ultrastructure of chloroplast and thylakoid of chrysanthemum leaves were observed,and the photosynthetic and physiological indices were measured.The results showed that the chloroplast and thyla-koid structures of chrysanthemum were damaged under high temperature stress.The chlorophyll contents and maximum fluorescence(Fm)were significantly reduced,while the OJIP curve changed with the fluorescence of K and J points increased.The net photosynthetic rate(P_(n)),transpiration rate(T_(r))and stomatal conductance(g_(s))were significantly decreased,while the internal CO_(2)concentration(C_(i))was significantly increased.The relative conductivity(REC),malondialdehyde(MDA),reactive oxygen species(ROS),osmotic adjustment substances content and antioxidant enzyme activity all increased significantly.Spraying exogenous MT onto leaves could maintain the integrity of chloroplast and thylakoid structure under high temperature in chrysanthemum and significantly decrease the increment in the K and J points of OJIP curve.Exogenous application of MT alleviated the inhibition of high temperature stress on photosynthesis and fluorescence of chrysanthemum,as indicated by significantly higher Fm,P_(n),g_(s),T_(r)and photosynthetic pigment contents and lower C_(i).Exogenous MT also significantly reduced the REC,MDA and ROS contents of chrysanthemum under high temperature stress,and enhanced the osmotic adjustment substances content and antioxidant enzyme activity in chrysanthemum leaves.It suggested that exogenous MT could protect the integrity of chloroplast structure of chrysanthemum leaves,enhance photosynthesis,inhibit the excessive production of ROS in the plants under high temperature stress,improve the activity of antioxidant enzyme system,reduce the level of membr

关 键 词：菊花 高温胁迫 褪黑素 光合 生理机制 

分 类 号：S682.11[农业科学—观赏园艺]