人参叶片衰老过程中叶片结构及生理指标变化  

Changes of leaf structure and physiological indexes during senescence of ginseng leaves

作　　者：杨玉坤 王英平[1] 杨鹤[1] 张浩[1] 王轶晗 YANG Yukun;WANG Yingping;YANG He;ZHANG Hao;WANG Yihan(Jilin Agricultural University,State Local Joint Engineering Research Center of Ginseng Breedng and Application,Changchun 130118,China)

机构地区：[1]吉林农业大学人参新品种选育与开发国家地方联合工程研究中心,长春130118

出　　处：《植物生理学报》2022年第2期393-401,共9页Plant Physiology Journal

基　　金：International Joint Research Center of Plants of the Genus Panax(20200802015GH);吉林省重大科技专项(20200504001YY)。

摘　　要：为了深入了解人参叶片衰老过程中组织结构、细胞器结构及相关生理指标的变化,结合显微观察与超微观察两种方法对人参叶片结构变化进行解剖学研究,并与人参叶片衰老过程中光合特性、叶绿素含量以及防御酶活性与H_(2)O_(2)荧光分布情况进行系统分析。显微观察结果表明:随着人参的叶片衰老,各层细胞厚度总体呈不同程度的下降趋势,第三时期观察到叶绿体数目的减少,第四时期的组织结构中几乎无法观察到叶绿体的存在。使用电镜进一步观察发现,此时叶绿体特征已完全消失,并形成大型的质体小球;从生理指标上来看,叶绿素含量与光合参数总体上均从衰老初期开始逐渐下降,且第三时期降低最为显著;叶片内3种防御酶活性总体均呈先升高再降低趋势;H_(2)O_(2)在保卫细胞中的荧光强度总体上不断增强,其中第三时期后,由于叶片中酶活性的降低,ROS不能被及时清除,最终叶片完成衰老。In order to further understand the process of organization structure,the organelles changes in structure and related physiological indexes in leaf senescence of ginseng(Panax ginseng),combining the microscopic observation and superfine observation to survey the anatomical structure change,while making a systematically analysis with characteristics of photosynthetic,content of chlorophyll,activity of defense enzyme and distribution of H_(2)O_(2) fluorescence.The results showed that with the senescence of ginseng leaf,the cell thickness of each layer showed a decreasing trend,the number of chloroplast was decreased in the third stage,and the chloroplast was almost not observed in the tissue structure of the fourth stage.Further observation by electron microscopy showed that the chloroplast characteristics had completely disappeared and large globules were formed.In terms of physiological indexes,chlorophyll and photosynthetic parameters decreased gradually from the beginning of senescence,and the decrease was most significant in the third stage.The activities of defense enzymes in leaves increased firstly and then decreased.The fluorescence intensity of H_(2)O_(2) in guard cells keeps increasing.After the third stage,ROS cannot be cleared in time due to the decrease of enzyme activity in leaves,and finally completed the aging process.

关 键 词：人参 叶片衰老 组织结构 叶绿体 

分 类 号：S567.51[农业科学—中草药栽培]