|
|
|
ROLE OF ABSCISIC
ACID (ABA) IN CONTROLLING THE HORMONAL BALANCE AT BOOTING AND
GRAIN-FILLING STAGES OF DIFFERENT WHEAT (TRITICUM
AESTIVUM L.) CULTIVARS UNDER DROUGHT
SUMERA IQBAL1
AND ASGHARI BANO2*
Abstract: Water shortage seriously influences wheat productivity in
various growing regions.The
response of two wheat (Triticum aestivum L.) accessions viz.,
011417 and 011320 to drought and exogenously applied abscisic acid was
determined in a pot study at booting and grain-filling stages to study
the role of stress hormone abscisic acid (ABA). Changes in endogenous
ABA (bound and free) and the growth promoting hormones i.e. trans zeatin
ribiside (t-zr), Indole-3-Acetic Acid (IAA) gibberellins (GA) were
monitored. Sampling was done 3, 6 and 9 days after induction of water
stress and at 48 and 72 h of re-watering. Marked decreases in t-zr, IAA
and GA were found to be associated with an increase in the free and
bound ABA content in the leaves under water stress. Sensitive accession
011320, showed the greater decrease in growth promoting hormones and
less accumulation of ABA. The inhibitory effects of water stress on
plant phytohormonal balance were ameliorated by exogenous ABA
application specifically at booting stage and particularly in the
sensitive accession 011320. There is a cultivar specific threshold ABA
level, which is required to exhibit any significant ameliorating effect
under water stress.
1Department
of Botany, Lahore College for Women University, Lahore, Pakistan.
2Department
of Plant Sciences, Quaid-i- Azam University, Islamabad, Pakistan.
Corresponding
author’s Email address:
asgharibano@yahoo.com
|
|
|