title: Changes of antioxidative enzymes and cell membrane osmosis in tomato colonized by arbuscular Mycorrhizae under NaCl stress.
abstract: Salinity toxicity is a worldwide agricultural and eco-environmental problem. Many literatures show that arbuscular mycorrhizal fungi (AMF) can enhance salt tolerance of many plants and some physiological changes occurred in AM symbiosis under salt stress. However, the role of ROS-scavenging enzymes in AM tomato is still unknown in continuous salt stress. This study investigated the effect of Glomus mosseae on tomato growth, cell membrane osmosis and examined the antioxidants (superoxide-dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX; peroxidase, POD) responses in roots of mycorrhizal tomato and control under different NaCl stress for 40 days in potted culture. NaCl solution (0, 0.5 and 1%) was added to organic soil in the irrigation water after 45 days inoculated by AMF (Glomus mosseae). (1) AMF inoculation improved tomato growth under salt or saltless condition and reduced cell membrane osmosis, MDA (malonaldehyde) content in salinity. So the salt tolerance of tomato was enhanced by AMF; (2) SOD, APX and POD activity in roots of AM symbiosis were significantly higher than corresponding non-AM plants in salinity or saltless condition. However, CAT activity was transiently induced by AMF and then suppressed to a level similar with non-AM seedlings; (3) higher salinity (1% level) and long stress time suppressed the effect of AMF on SOD, APX, POD and CAT activity; (4) this research suggested that the enhanced salt tolerance in AM symbiosis was mainly related with the elevated SOD, POD and APX activity by AMF which degraded more reactive oxygen species and so alleviated the cell membrane damages under salt stress. Whereas, the elevated SOD, POD and APX activity due to AMF depended on salinity environment.
authors.affiliation: Institute of Vegetables and Flowers, Chinese Academy of Agricultural Science, Beijing 100081, PR China.
authors.forename: Zhongqun
authors.initials: Z
authors.lastname: He
authors.forename: Chaoxing
authors.initials: C
authors.lastname: He
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Zhang
authors.forename: Zhirong
authors.initials: Z
authors.lastname: Zou
authors.forename: Huaisong
authors.initials: H
authors.lastname: Wang
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D004553:Electric Conductivity; D018551:Solanum lycopersicum / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism / Q000382:microbiology*; D038821:Mycorrhizae / Q000378:metabolism*; D009995:Osmosis; D009997:Osmotic Pressure; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012965:Sodium Chloride / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D012965:Sodium Chloride