93. ごま葉枯病菌が感染したイネsl変異体におけるインドール-3-酢酸の蓄積(口頭発表,植物化学調節学会第46回大会)

概要

論文の詳細を見る
Rice plant accumulates serotonin in response to pathogen attack. sl mutant that is deficient in the conversion of tryptamine to serotonin accumulates tryptamine instead of serotonin in the leaves inoculated with Bipolaris oryzae. The accumulation of tryptamine was accompanied by a marked increase in indole-3-acetic acid (IAA) concentration in the leaves. We investigated the effects of inoculation of other pathogenic fungi and treatment of elicitor. The accumulation of IAA was induced by inoculation of B. sorokiniana, but the inoculation of Magnaporthe grisea and treatment of CuCl_2 was ineffective, indicating that the IAA accumulation is not necessarily linked to induction of defense responses. In addition, we found that when tryptamine was supplemented to the medium, B. oryzae converted it to IAA. These findings suggested that the accumulation of IAA in the sl leaves was the result of the conversion of tryptamine to IAA by B. oryzae. We further examined the effects of tryptamine and serotonin on the growth of B. oryzae for understanding of the physiological significance of the conversion. The growth of B. oryzae was significantly inhibited by high concentrations of trypamine and serotonin. We also found that B. oryzae converted serotonin to 5-hydroxy IAA. It is thus likely that the conversion of indole amines to corresponding carboxylic acids is the detoxification process of indole amines in B. oryzae.
2011-10-03