Abstract
The most remarkable characteristic of deepwater rice is rapid internode elongation when subjected to deep water. Deepwater rice does not show significant internode elongation in shallow water, whereas deep water induces dramatic internode elongation. Most ordinary rice cultivars planted in irrigated fields do not have this characteristic. Deepwater rice is mainly cultivated in lowland areas of South and Southeast Asia where the severe flood is occurred during the rainy season. Rapid internode elongation in response to deep water in deepwater rice is necessary to avoid anoxia. Deepwater rice elongates internodes to keep the top leaves above the water surface to allow gas exchange.
Recently, we isolated the SNORKEL1 (SK1) and SNORKEL2 (SK2) which are responsible for deepwater response. The functional analyses of SK1 and SK2 indicated that these genes were ERF type transcription factors which encoded AP2/ ERF domain and involved in signaling of gaseous phytohormone, ethylene. Our previous results suggested that the SK genes are involved in the ethylene signal transduction. Here we show the analyses of the relationship between SK genes and downstream genes.
