H. Onouchi et G. Coupland, THE REGULATION OF FLOWERING TIME OF ARABIDOPSIS IN RESPONSE TO DAYLENGTH, Journal of plant research, 111(1102), 1998, pp. 271-275
The control of flowering time by photoperiod has been studied genetica
lly in Arabidopsis by several groups. Arabidopsis flowers earlier unde
r long-day (LD) conditions than under short days (SD) and mutations ha
ve been identified that specifically either delay flowering under LDs
or promote flowering under SDs. The phenotypes of single and double mu
tants suggest that the mutations that specifically delay LD flowering
affect genes in a single genetic pathway. Four of the genes affected b
y these mutations were cloned by different research groups, and their
sequences suggested functions for the gene products. One of the genes,
CONSTANS, was proposed to encode a transcription factor, and its mRNA
is present at a higher abundance in LDs than SDs suggesting its trans
criptional regulation is important in the promotion of flowering. In a
greement with this its overexpression in transgenic plants is sufficie
nt to promote early flowering under SDs, The approaches being taken to
establish the order with which genes act within the pathway and to id
entify genes that act after CONSTANS are described.