The NAC transcription factor RIM1 of rice is a new regulator of jasmonate signaling.
Jasmonates (JAs) are lipid-derived regulators that play crucial roles in both host immunity and development. We recently identified the NAC transcription factor RIM1 as a host factor involved in multiplication of rice dwarf virus (RDV). Here, we report that RIM1 functions as a transcriptional regulator of JA signaling and is degraded in response to JA treatment via a 26S proteasome-dependent pathway. Plants carrying rim1 mutations show a phenotype of root growth inhibition. The expression profiles of the mutants were significantly correlated with those of JA-treated wild-type plants without accumulation of endogenous JA, indicating that RIM1 functions as a component of JA signaling. The expression of genes encoding JA biosynthetic enzymes (lipoxygenase (LOX), allene oxide synthase 2 (AOS2) and OPDA reductase 7 (OPR7)) was up-regulated in the rim1 mutants under normal conditions, and a rapid and massive accumulation of endogenous JA was detected in the mutants after wounding. These results suggest that RIM1 may represent a new molecular link in jasmonate signaling, and may thereby provide new insights into the well-established coronatine-insensitive 1 (COI1)-Jasmonate ZIM-domain (JAZ) JA signaling pathway.
Yoshii
Motoyasu
M
National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan.
Yamazaki
Muneo
M
Rakwal
Randeep
R
Kishi-Kaboshi
Mitsuko
M
Miyao
Akio
A
Hirochika
Hirohiko
H
D003517:Cyclopentanes / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; D018749:RNA, Plant; D014157:Transcription Factors; C011006:jasmonic acid; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease