Expression profiling of marker genes for salicylic acid, jasmonic acid and ethylene in Brachypodium distachyon highlights its similar defense mechanism to rice
Y. NOUTOSHI (1), Y. Kouzai (1), M. Kimura (1), Y. Yamanaka (1), M. Watanabe (1), H. Matsui (1), M. Yamamoto (1), Y. Ichinose (1), K. Toyoda (1), Y. Onda (2), K. Mochida (2) (1) Okayama University, Japan; (2) RIKEN CSRS, Japan

Brachypodium distachyon is a promising model plants for grasses including cereals and biomass crops. Since infectivity on Brachypodium of various pathogens threatening world crop cultivation has been verified so far, it provides an alternative platform for investigating disease resistance mechanism in monocotyledonous plants. As a counterpart of Arabidopsis and rice, Brachypodium can be used to display the commonality and uniqueness of defence systems among plant species as well. In this study, we look for Brachypodium responsive marker genes for phytohormones suitable for defence-response monitoring. 34 candidate genes for salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) on the basis of protein-sequence similarity to known marker genes used in Arabidopsis and rice and their transcription levels were measured 24 and 48 h after hormone treatments. Two genes for SA, 7 for JA and 2 for ET were significantly induced at either or both time points. In addition, phylogenetic analysis and expression profiling of 11 genes encoding pathogenesis-related (PR) 1 protein revealed that Brachypodium contains PR1-family genes to rice with the similar responsive patterns to phytohormones. Our results using Brachypodium suggest that monocots share a characteristic immune system, defined as the common defence system in contrast to dicots.

Abstract Number: P16-464
Session Type: Poster