Salicylic Acid-Mediated Stress-Induced Flowering

Abstract

Plants have a tendency to flower under unsuitable growth conditions. Stress factors, such as poor nutrition, high or low temperature, high- or low-intensity light, and ultraviolet light, have been implicated in this stress-induced flowering. The stressed plants do not wait for the arrival of a season when photoperiodic conditions are suitable for flowering, and such precocious flowering might assist in species preservation. Stress-induced flowering has been well studied in Pharbitis nil (synonym Ipomoea nil), Perilla frutescens var. crispa, Lemna paucicostata (synonym Lemna aequinoctialis) and Arabidopsis thaliana. The phenylalanine ammonia-lyase (PAL) inhibitor suppresses stress-induced flowering in P. nil, and this effect was reversed with salicylic acid (SA). The PAL gene expression, PAL enzyme activity and SA content in the cotyledons increased during stress-induced flowering. These results suggest that SA mediates stress-induced flowering.