title: Influence of arbuscular mycorrhiza on the growth and antioxidative activity in cyclamen under heat stress.
abstract: The influence of the arbuscular mycorrhizal (AM) fungus, Glomus fasciculatum, on the growth, heat stress responses and the antioxidative activity in cyclamen (Cyclamen persicum Mill.) plants was studied. Cyclamen plants (inoculated or not with the AM fungus) were placed in a commercial potting media at 17-20 °C for 12 weeks in a greenhouse and subsequently subjected to two temperature conditions in a growth chamber. Initially, plants were grown at 20 °C for 4 weeks as a no heat stress (HS-) condition, followed by 30 °C for another 4 weeks as a heat stress (HS+) condition. Different morphological and physiological growth parameters were compared between G. fasciculatum-inoculated and noninoculated plants. The mycorrhizal symbiosis markedly enhanced biomass production and HS + responses in plants compared to that in the controls. A severe rate of leaf browning (80-100%) was observed in control plants, whereas the mycorrhizal plants showed a minimum rate of leaf browning under HS + conditions. The mycorrhizal plants showed an increase activity of antioxidative enzymes such as superoxide dismutase and ascorbate peroxidase, as well as an increase in ascorbic acid and polyphenol contents. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity also showed a greater response in mycorrhizal plants than in the control plants under each temperature condition. The results indicate that in cyclamen plants, AM fungal colonisation alleviated heat stress damage through an increased antioxidative activity and that the mycorrhizal symbiosis strongly enhanced temperature stress tolerance which promoted plant growth and increased the host biomass under heat stress.
authors: The United Graduate School of Agricultural Science, Gifu University, Gifu 501-1193, Japan.
authors: Moslama Aktar
authors: MA
authors: Maya
authors: Yoh-ichi
authors: Y
authors: Matsubara
mesh_terms: D059827:Agricultural Inoculants / Q000502:physiology; D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000378:metabolism; D031824:Cyclamen / Q000201:enzymology / Q000254:growth & development* / Q000382:microbiology* / Q000502:physiology; D055137:Glomeromycota / Q000502:physiology*; D006358:Hot Temperature; D038821:Mycorrhizae / Q000502:physiology*; D010940:Plant Proteins / Q000378:metabolism*; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000378:metabolism; D013559:Symbiosis
chemical_list: D000975:Antioxidants; D010940:Plant Proteins; D060387:Ascorbate Peroxidases; D013482:Superoxide Dismutase