OsRCI-1 -Mediated GLVs Enhance Rice Resistance to Brown Planthoppers

Green leaf volatiles (GLVs) play pivotal roles in plant anti-herbivore defense. This study investigated whether the rice 13-lipoxygense gene is involved in GLV production and plant defense in rice. The overexpression of ( lines) in rice resulted in increased wound-induced levels of two prominent GLVs, -3-hexen-1-ol and -3-hexenal. In a previous study, we found that the overexpression of reduced the colonization by the rice brown planthopper (BPH, ) but increased the attractiveness to the egg parasitoid compared to wild-type (WT) plants. This study found that when -3-hexen-1-ol, but not -3-hexenal, was added to WT plants, it could change the BPH's colonization preference, i.e., more BPHs preferred to colonize the lines. The exogenous application of -3-hexen-1-ol or -3-hexenal to BPH-infested WT plants could weaken or overturn the preference of for lines. However, field experiments revealed that only -3-hexenal was attractive to the parasitoid and increased the parasitism rates of BPH eggs. These results indicate that is involved in rice GLV production and therefore modulates both direct and indirect defense in rice.