Involvement of the basic helix-loop-helix transcription factor RERJ1 in wounding and drought stress responses in rice plants.

The jasmonic acid (JA)-responsive gene RERJ1 isolated from suspension-cultured rice cells encodes a transcription factor with a basic helix-loop-helix motif. In this study, we found that RERJ1 is also expressed in rice plants in response to JA, and that its expression in rice leaves is up-regulated by exposure to wounding and drought stress. It is also suggested that JA but not abscisic acid is involved in the up-regulation of RERJ1 expression caused by wounding and drought stress.

RERJ1, a jasmonic acid-responsive gene from rice, encodes a basic helix-loop-helix protein.

Differential screening of a cDNA library constructed using poly(A)(+) RNA from suspension-cultured rice cells treated with jasmonic acid (JA) for 1/2h yielded a cDNA of a gene tentatively named RERJ1 that is upregulated in response to exogenous JA. Northern blot analysis indicated that the RERJ1 mRNA levels peaked at 1/2-1h after the addition of jasmonic acid and then decreased gradually. RERJ1 encodes a transcriptional regulator with a basic helix-loop-helix motif.

Cloning and characterization of a jasmonic acid-responsive gene encoding 12-oxophytodienoic acid reductase in suspension-cultured rice cells.

In suspension-cultured rice ( Oryza sativaL.) cells, jasmonic acid (JA) functions as a signal transducer in elicitor N-acetylchitoheptaose-induced phytoalexin production. Differential screening of a cDNA library constructed using poly(A)(+) RNA from suspension-cultured rice cells treated with JA (10(-4) M) for 2 h yielded a cDNA for a gene that responded to exogenous JA by an increase in mRNA level.

Cloning and characterization of cDNAs for the jasmonic acid-responsive Genes RRJ1 and RRJ2 in suspension-cultured rice cells.

Two cDNA clones for jasmonic acid (JA)-responsive genes, RRJ1 and RRJ2, were isolated by differential screening from suspension-cultured rice cells treated with JA for 2 h. The putative RRJ1 protein is completely identical to that of a putative rice cystathionine gamma-lyase, while the putative RRJ2 protein is highly similar in sequence to a rice pyruvate decarboxylase, PDC1.