Search

ABSTRACTGlobal water shortage seriously threatens rice growth especially in irrigated production areas. Association of plants with beneficial soil microbes is one strategy for plant adaption to environmental stresses. In this study, rice (Oryza sativaL.) plants were colonized by the beneficial root-colonizing endophytic fungus Piriformospora indica(P. indica). We demonstrate that grain yield were higher in P. indica-colonized rice plants compared to the uncolonized plants grown in soil. Moreover, P. indicaeffect on improving water stress tolerance in rice and its physiological mechanism were investigated in a hydroponic culture system. Polyethylene glycol (PEG) was applied to the culture solution to conduct the water stress condition. Water stress-induced leaf wilting and impairments in photosynthetic efficiency were diminished in P. indica-colonized plants. Furthermore, P. indicacolonization promotes stomata closure and increases the leaf surface temperature under water stress. The malondialdehyde level (as an indicator for oxidative stress) was lower and the reduced to oxidized glutathione ratio was higher in P. indica-colonized and PEG-exposed rice plants compared to the uncolonized plants. Furthermore, the activities of the antioxidant enzymes catalase and glutathione reductase were up-regulated in inoculated rice seedlings under water stress. In conclusion, P. indicapromotes rice performance under water stress by stomata closure and lower oxidative stress.