Abstract
For understanding the molecular mechanism of flower induction in Pharbitis nil, we have isolated a PNJ1, which encodes a small chaperone-like protein, as a flower-induction specific gene. A DST consensus of mRNA instability was found in PNJ1, indicating the strict expression control. Cotyledonous PNJ1 mRNA transiently increased after the transition of the plants from light to dark. Under the continuous darkness, the PNJ1 mRNA showed circadian oscillation. White light in turn rapidly reduced PNJ1 mRNA. Red and blue light exhibited different kinetics of PNJ1 mRNA decrease. Under continuous red light, the PNJ1 mRNA was transiently reduced but restored to the initial level. PNJ1 mRNA exhibited a very short half-life of 4.3 min just after the red light irradiation. However, PNJ1 mRNA was progressively eliminated under the continuous blue light. Taken together, rapid decrease in PNJ1 mRNA under the white light may be a combination of red and blue light function.
