Abstract
Arabidopsis thaliana changes its architecture dependent on environmental condition, temperature, light-intensity, and R/FR-ratio. Under high temperature condition hypocotyls and petioles are elongated like as under low R/FR-ratio condition. We study the molecular mechanism of this morphogenesis at high temperature.
At first, we report the correlation between temperature and light-intensity in morphogenesis. High irradiance diminished morphological changes mentioned above at 28 degrees. This result suggests that temperature and light-intensity signals are cross-talked. Secondary, to identify genes involved in the temperature-signaling pathway we isolated several temperature-insensitive mutants that prevent hypocotyl and petiole elongation at 28 degrees. At one of them, we found that the T-DNA was inserted in Phytochrome Interacting Factor4 (PIF4) gene and no PIF4 mRNA was detected. In wild-type plants, PIF4 mRNA was increased at 28 degrees compared at 22 degrees. Our data suggests that PIF4 function is essential for elongation of hypocotyls and petioles under high temperature.
