Abstract:
The response of plants to drought stress depends on
several factors including the plant
developmental stage and the length and severity of
the stress applied. Common bean
(
Phaseolus vulgaris
L.) is the most important pulse crop that is culti
vated worldwide for
human consumption. Understanding of the mechanisms
responsible for its response to
drought is, therefore, essential. An increasing num
ber of reports show that withdrawal of
water from plants growing in the controlled conditi
ons is accompanied by changes in the
expression of a number of genes. To our knowledge,
regulation of gene expression in
flower buds of
P. vulgaris
under stress conditions has not been reported. Our
aim was to
identify transcription sensitivity of
CA7
and
NCED
genes under water deficit stress at
vegetative and reproductive stages of different bea
n genotypes. Two experiments were
carried out. Within each experiment, the groups of
drought-stressed plants were
subjected to water withholding, while the control p
lants were watered every other day.
Stressed plants were re-irrigated when RWC reached
66±2 percent. Our study showed
that
CA7
and
NCDE
were genes differentially expressed in the studied
genotypes under
drought stress. The expression of these genes was s
trongly induced in response to drought
stress in flower buds of the cultivar Jules and the
line KS-21191. It seems that under
stress conditions, these genes express more in the
tolerant than the susceptible genotypes.
Therefore, these two genes could probably be used t
o obtain plants relatively tolerant to
water deficit stress, especially in the reproductiv
e stage of plant growth.
Keywords:
Flower buds, Gene expression,
Phaseolus vulgaris
, Water deficit
.
