Abstract
Pharbitis nil can flower when treated by several stress factors. The plants flowered by stress form normal progeny. This stress-induced flowering is induced by transmissible flowering stimulus, and mediated by salicylic acid (SA) regulated by PAL. PnFT, homolog of FT is also involved. In the present study, we applied stress factors to two varieties of P. nil, and determined the PAL activity, endogenous SA level and expression level of flowering genes along with the flowering response. Poor nutrition stress induced flowering in var. Violet, enhanced PAL activity and SA level, and induced the expression of PnFT2. The expression of PnFT1, SOC1 homolog, PnCO, homologs of FLC, FCA and FRI and PnFVE was not induced or the expression of them was not influenced by the stress. Violet was induced to flower by low-temperature stress, and both PnFT1 and PnFT2 were expressed although the expression of PnFT1was quite small. Var. Tendan was not induced to flower by poor nutrition stress, and the expression of PnFT was not detected. Tendan flowered by low temperature stress, and PnFT2 was expressed. The stress treatments never influenced the expression of SOC1 homolog and PnCO.
