低温对大花丹桂叶肉细胞超微结构的影响  

The effects of low temperature stress on mesophyll cells ultrastructure in Osmanthus fragrans ‘Dahua Dangui’

作　　者：尤扬 王贤荣 张晓云 YOU Yang;WANG Xian-rong;ZHANG Xiao-yun(College of Biology and Environment,Nanjing Forestry University,Nanjing 210037,China;School of Horticulture and Landscape Architecture,Henan Institute of Science and Technology,Xinxiang 453003,China)

机构地区：[1]南京林业大学生物与环境学院,江苏南京210037 [2]河南科技学院园艺园林学院,河南新乡453003

出　　处：《甘肃农业大学学报》2018年第4期100-106,共7页Journal of Gansu Agricultural University

基　　金：河南省科技计划项目(162102110155);河南省高等学校重点科研项目(15A220002);河南省教育厅科学技术研究重点项目(13A180307);新乡市科技创新发展专项项目(CXGG16029)

摘　　要：【目的】探讨桂花(Osmanthus fragrans)在低温过程叶肉细胞超微结构的变化,揭示低温胁迫下桂花在细胞学水平上的响应机制.【方法】以2年生‘大花丹桂’(O.fragrans‘Dahua Dangui’)为试材,采用智能人工气候室模拟低温条件处理桂花,用透射电子显微镜观察叶肉细胞超微结构的变化.【结果】5℃低温处理时‘大花丹桂’叶绿体与对照相比有肿胀现象,嗜锇体开始增多,线粒体嵴结构完整;0℃和-5℃胁迫时叶绿体膨胀加剧,细胞内线粒体的数量比对照和5℃处理时有增加现象;-10℃和-15℃处理时,叶肉细胞发生严重的质壁分离,细胞器崩溃降解:大部分叶绿体向细胞中央游离,形态扭曲,甚至部分叶绿体解体;线粒体双层膜结构完整,但已没有较为明显的嵴结构.【结论】‘大花丹桂’叶肉细胞中叶绿体在低温下的反应非常灵敏,叶绿体的稳定性可作为桂花耐寒性鉴定的一个重要参考指标.【Objective】To study the ultrastructural changes of Osmanthus fragrans mesophyll cells and to reveal its cold-stress response mechanisms.【Method】2-year-old O.fragrans‘Dahua Dangui’were treated in an artificial climate chamber that simulated low-temperature processing.The ultrastructural changes in the mesophyll cells were observed using a transmission electron microscope.【Result】At 5℃,chloroplasts underwent swelling,osmiophilic granules increased,and mitochondrial cristae structures were intact compared with the control.At 0℃and-5℃,the chloroplast swelling increased,the number of mitochondria in the cell increased compared with the control and with the number at 5℃.At-10℃and-15℃,the mesophyll cells underwent severe plasmolysis,and organelles collapsed and degraded.Most chloroplasts dissociated to the cell centers.Their shapes contorted and some even disintegrated.Mitochondrial double membranes structure remained intact,but there were no apparent cristae structure.【Conclusion】Thus,chloroplasts in the mesophyll cells of O.fragrans‘Dahua Dangui’are sensitive to low temperatures.Their stability can,therefore,be used as an important reference index to identify cold tolerance in O.fragrans.

关 键 词：大花丹桂 超微结构 低温胁迫 

分 类 号：S684[农业科学—观赏园艺]