Abstract The relative expression level of YUCAA1 gene and the amount of endogenous IAA both in RSV infected rice plants and rice suspension cells were investigated by real-time RT-PCR and high performance liquid chromatography respectively. In rice suspension cells, RSV infection resulted that the expression of YUCAA1 gene and the amount of endogenous IAA were increased 2.98 and 2.66 times respectively. Whereas in rice plants, RSV infection leaded to decrease 70% and 75% on the expression of YUCAA1 and the amount of endogenous IAA respectively. These results indicated that RSV infection could induce auxin signal transduction in rice. At the same time, the expression of RSV CP was increased 2.9 times in rice plant with KPSC buffer treatment after depleting endogenous auxins, and was decreased 45% with 30 μM IAA treatment. These suggested that auxin could regulate RSV replication in rice plant.
