摘要
采用磷酸铅沉淀的电镜细胞化学方法,对经冷驯化及未经冷驯化的金边卫矛 EuonymusradicansEmorald&Gold. 以及两者在-5℃下处理1d后的叶肉细胞进行了ATPase的超微细胞化学定位的比较观察,并对冷驯化可提高植物抗寒力及ATPase与植物抗寒性关系进行了探讨.标志ATPase活性反应的磷酸铅沉淀物主要分布在叶片栅栏细胞和海绵细胞的质膜和液泡膜上,ATPase在这两类细胞中的分布及活性无明显差异.金边卫矛幼苗经4℃低温驯化7d后,其质膜和液泡膜的ATPase活性高于22℃下生长的幼苗,冷驯化后的金边卫矛幼苗在-5℃处理1d后,其质膜和液泡膜上仍可观察到ATPase的活性反应,但较低温胁迫前有所降低,且超微结构完整,未见任何伤害.而未经冷驯化的金边卫矛幼苗在-5℃处理1d后,其质膜和液泡膜上的ATPase完全失活,同时细胞的超微结构受到严重伤害.实验结果表明,冷驯化可提高金边卫矛幼苗ATPase在低温胁迫下的稳定性,这种活性变化与植物抗寒力的提高呈正相关,同时还发现液泡膜ATPase活性较质膜ATPase变化幅度大,推测液泡膜可能较质膜ATPase对低温更为敏感.
With electromicroscopic-cytochemical assay,comparative observation on the ultracytochemical localization of ATPase in the mesophyll cells of Euonymus radicans was carried out when the seedlings were cold-acclimated or not and then they were treated at -5℃ for 1 d.Also,the enhancement of chilling resistance induced by cold acclimation and the relationship between the ATPase and the plant chilling resistance was discussed.The electron-dense lead phosphate deposits,an indication of ATPase activity,mainly distributed on the plasma membrane and tonoplast in the mesophyll cells of palisade and spongy tissue,in which there is no obvious differences of ATPase distribution and activities.When seedlings were cold-acclimated at 4℃ for 7 d,the ATPase activities on the PM and tonoplast were higher than those of the seedlings treated at 22℃.When the cold-acclimated seedlings were then treated at -5℃ for 1 d,the ATPase activities were still observed on the PM and tonoplast,but it was lower than before low temperature stress,and the ultrastructure of mesophyll cells remained unchanged.However,the ATPase in mesophyll cells became inactivation and the ultrastructrue of cells damaged seriously when the non-cold-acclimated seedlings were treated at -5℃ for 1 d.The results indicate that cold-acclimation has enhanced the stability of ATPase activities of seedlings under low temperature stress,and the change regularities of ATPase was positively related to the enhancement of chilling resistance of plants.Also,it was noticed that the tonoplast ATPase activities changed more drastically than that of the PM ATPase,therefore,it is suggested that tonoplast might be more sensitive than PM to low temperature.
出处
《西北植物学报》
CAS
CSCD
2004年第4期563-569,共7页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家林业局" 948" 国际引进项目(99-04)资助
