Abstract: By Petri dish culture, an experiment of simulated drought stress was carried out by 20% polyethylene glycol (PEG 6000), to examine the effects of endophytic fungus (Piriformospora indica) on the growth and drought resistance of upland rice. The results showed that the biomass of rice seedlings significantly increased after colonization with P. indica for 23 days, with two-folds in total root length and total root surface area, and four-folds in the number of root tips. Under 20% PEG drought stress, the progress of leaf wilting and curling was slowed down, and the leaf temperature raised in the treatment with P. indicainoculation. With the extension of drought stress duration, the difference of leaf temperature in the treatment with P. indica inoculation was greater than that in the non-inoculated treatment. The expression levels of responsive genes related to drought stress, including OsMYB2, OsCIPK3,OsCDPK7 and OsCATB, were up-regulated in leaves of upland rice induced by P. indica with the extension of drought stress duration. In conclusion, P. indica inoculation could promote the growth and enhance the drought tolerance of upland rice.

Key words: N deposition, precipitation regime, soil acidification, water addition