Antimicrobial Activity of UV-Induced Phenylamides from Rice Leaves

Molecules

Hye Lin Park²  Youngchul Yoo¹  Tae-Ryong Hahn²  Seong Hee Bhoo²  Sang-Won Lee¹  Man-Ho Cho² 

[1] Department of Plant Molecular Systems Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 446-70, Korea; E-Mail:;Graduate School of Biotechnology, Kyung Hee University, Yongin 446-70, Korea; E-Mails:

关键词: rice;    UV treatment;    phenylamide;    phytoalexin;    N-trans-cinnamoyltryptamine;    N-p-coumaroylserotonin;    N-trans-cinnamoyltyramine;    N-benzoyltryptamine;    antimicrobial activity;   

DOI  :  10.3390/molecules191118139

来源: mdpi

【 摘 要 】

Rice produces a wide array of phytoalexins in response to pathogen attacks and UV-irradiation. Except for the flavonoid sakuranetin, most phytoalexins identified in rice are diterpenoid compounds. Analysis of phenolic-enriched fractions from UV-treated rice leaves showed that several phenolic compounds in addition to sakuranetin accumulated remarkably in rice leaves. We isolated two compounds from UV-treated rice leaves using silica gel column chromatography and preparative HPLC. The isolated phenolic compounds were identified as phenylamide compounds: N-trans-cinnamoyltryptamine and N-p-coumaroylserotonin. Expression analysis of biosynthetic genes demonstrated that genes for arylamine biosynthesis were upregulated by UV irradiation. This result suggested that phenylamide biosynthetic pathways are activated in rice leaves by UV treatment. To unravel the role of UV-induced phenylamides as phytoalexins, we examined their antimicrobial activity against rice fungal and bacterial pathogens. N-trans-Cinnamoyltryptamine inhibited the growth of rice brown spot fungus (Bipolaris oryzae). In addition to the known antifungal activity to the blast fungus, sakuranetin had antimicrobial activity toward B. oryzae and Rhizoctonia solani (rice sheath blight fungus). UV-induced phenylamides and sakuranetin also had antimicrobial activity against rice bacterial pathogens for grain rot (Burkholderia glumae), blight (Xanthomonas oryzae pv. oryzae) and leaf streak (X. oryzae pv. oryzicola) diseases. These findings suggested that the UV-induced phenylamides in rice are phytoalexins against a diverse array of pathogens.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.