摘要
以皋月杜鹃(Rhododendron indicum)为材料,采用盆栽试验研究不同浓度盐胁迫对杜鹃花生理生化特征和叶绿体亚显微结构的影响.结果表明:在低盐胁迫下,植株生长健壮,可溶性蛋白质含量、过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)活性均显著高于对照,叶绿素和丙二醛(MDA)含量增加不显著,叶绿体亚显微结构完好,基粒片层排列整齐,与对照无差异,表明杜鹃可在低NaCl含量的土壤中正常生长;在120 mmol·L-1NaCl溶液处理下,植株叶片开始出现较轻的受害症状,随着盐浓度升高,植株受害症状加重,可溶性蛋白质和叶绿素含量显著下降,而MDA含量显著上升,POD、CAT和SOD活性先升后降,叶绿体结构逐渐膨胀成圆形,空洞化程度渐渐变大,膜慢慢解体,表明杜鹃在一定程度上具有抗盐胁迫的能力;在高盐胁迫下,叶绿体结构和功能被破坏,叶片黄化衰老.
A series of pot experiments were conducted to understand the effects of salt stress on physiological-biochemical characteristics and chloroplast submicroscopic structure of Rhododendron indicum.The results indicated a robust development of the individuals under low salt stress.The contents of soluble protein,catalase（CAT）,peroxidase（POD） and superoxide dismutase（SOD） activities were significantly higher than those of the control,while the variation of malondialdehyde（MDA） and chlorophyll concentrations were not significant.Submicroscopic observation suggested an unmodified structure of chloroplasts under low salt stress,and chloroplast grana lamella showed high level of regularity with not significant difference to that of the control.These results above indicates high fitness of R.indicum in the soil with relatively low NaCl concentration.However,under 120 mmol·L-1 NaCl concentration,the leaves of R.indicum began to show mild symptoms,and illustrated a positive relationship between the level of damage and the increment of salt concentration in soil.With the salt stress increased,the contents of soluble protein and chlorophyll decreased,while MDA content increased significantly,and POD,CAT and SOD activities increased first and decreased afterwards,and the chloroplasts showed an increase in dimension and became spherical in appearance,and the degree of cavity in chloroplasts increased with slow disintegration of their membrane,indicating that Rhododendron displayed certain level of salt resistance.But the structure and function of chloroplasts of R.indicum became increasingly damaged under high salt stress,which further led to the etiolation and senescence of its leaves.
出处
《浙江大学学报（农业与生命科学版）》
CAS
CSCD
北大核心
2011年第6期642-648,共7页
Journal of Zhejiang University:Agriculture and Life Sciences
基金
浙江省重大科技专项重点农业资助项目(2009C12092)
关键词
盐胁迫
杜鹃花
生理生化特征
叶绿体亚显微结构
salt stress
Rhododendron indicum
physiological-biochemical characteristics
chloroplast submicroscopic structure
