Pathogen attack and abiotic stress affect grain yields in rice fields worldwide. Rice leaf blast is caused by the fungal pathogen Magnaporthe oryzae, whereas rice leaf blight is caused by the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo). Rice leaf blast and blight, the two most destructive diseases in rice, result in huge yield losses. We therefore tried to identify a chemical that could be utilized as an inhibitor of rice leaf blast and blight. Here, we show that both bacterial-induced rice blight and fungal-induced rice blast can be controlled by auranofin, an anti-rheumatoid arthritis and anti-cancer drug used in humans. Auranofin directly inhibited the growth of four Xoo strains, including PXO99, KACC10208, 1209, and 1308. In addition, auranofin effectively controlled the growth of 10 M. oryzae strains, including KACC46531, 46532, 46534, 46535, 46536, 46538, 46540, 46541, 46542, and 46544, although its effect on M. oryzae was weaker than that on Xoo. These results suggest that auranofin can be applied to rice to block both rice leaf blight and blast caused by Xoo and M. oryzae, respectively.

Resveratrol is a stilbenoid and phytoalexin produced in response to stresses, such as wounding, and pathogen attacks by bacteria or fungi. Two resveratrol rice lines, Iksan515 and Iksan526, were used to examine resistance against Korean pathogen races for bacterial blight, leaf blast, and brown leaf spot. The screening test for bacterial blight demonstrated an increased susceptibility of both transgenic lines to K1 race, and a more susceptible Iksan515 to K2. Phenotypic evaluation for resistance to brown leaf spot also revealed the susceptibility of Iksan526 to the disease which did not significantly differ from the isogenic variety ‘Dongjin’, and a slightly more susceptible Iksan515 to the disease compared to check. When the lines were screened with three races (KJ301, KJ101 and KJ133) of leaf blasts in the field, both transgenic lines exhibited resistance but at the same level with ‘Dongjin’. Our overall findings suggest that foreign phytoalexin resveratrol production in transgenic rice lines transformed with resveratrol synthase gene did not confer resistance against fungal and bacterial diseases.

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• Effect of genetically modified rice producing resveratrol on the soil microbial communities
  Soo-In Sohn, Young-Ju Oh, Byung-Yong Kim, Soon-Jong Kweon, Hyun-Suk Cho, Tae-Hoon Ryu
  Journal of the Korean Society for Applied Biological Chemistry.2015; 58(6): 795.     CrossRef