The relationship of drought-related gene expression in Arabidopsis thaliana to hormonal and environmental factors.
Almost 2000 drought-responsive genes were identified in Arabidopsis thaliana under progressive soil drought stress using whole-genome oligonucleotide microarrays. Most of the drought-regulated genes recovered to normal expression levels by 3 h after rewatering. It has previously been shown that the abscisic acid (ABA) analogue (+)-8'-acetylene-ABA (PBI425) hyperinduces many ABA-like changes in gene expression to reveal a more complete list of ABA-regulated genes, and it is demonstrated here that PBI425 produced a correspondingly increased drought tolerance. About two-thirds of drought-responsive genes (1310 out of 1969) were regulated by ABA and/or the ABA analogue PBI425. Analysis of promoter motifs suggests that many of the remaining drought-responsive genes may be affected by ABA signalling. Concentrations of endogenous ABA and its catabolites significantly increased under drought stress and either completely (ABA) or partially (ABA catabolites) recovered to normal levels by 3 h after rehydration. Detailed analyses of drought transcript profiles and in silico comparisons with other studies revealed that the ABA-dependent pathways are predominant in the drought stress responses. These comparisons also showed that other plant hormones including jasmonic acid, auxin, cytokinin, ethylene, brassinosteroids, and gibberellins also affected drought-related gene expression, of which the most significant was jasmonic acid. There is also extensive cross-talk between responses to drought and other environmental factors including light and biotic stresses. These analyses demonstrate that ABA-related stress responses are modulated by other environmental and developmental factors.
Plant Biotechnology Institute, National Research Council of Canada, 110 Gymnasium Place, Saskatoon S7N 0W9, Canada.
Daiqing
D
Huang
Weiren
W
Wu
Suzanne R
SR
Abrams
Adrian J
AJ
Cutler
D000040:Abscisic Acid / Q000031:analogs & derivatives / Q000502:physiology*; D000222:Adaptation, Physiological; D000598:Amino Acids, Cyclic / Q000378:metabolism; D017360:Arabidopsis / Q000502:physiology*; D060406:Brassinosteroids; D002777:Cholestanols / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005875:Gibberellins / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D054883:Oxylipins / Q000378:metabolism; D010937:Plant Growth Regulators / Q000502:physiology*; D016133:Polymerase Chain Reaction; D050436:Regulatory Elements, Transcriptional; D013260:Steroids, Heterocyclic / Q000378:metabolism; D014867:Water / Q000502:physiology*
D000598:Amino Acids, Cyclic; D060406:Brassinosteroids; D002777:Cholestanols; D003517:Cyclopentanes; D005875:Gibberellins; D007210:Indoleacetic Acids; D054883:Oxylipins; D010937:Plant Growth Regulators; D013260:Steroids, Heterocyclic; D014867:Water; C023863:1-aminocyclopropane-1-carboxylic acid; C011006:jasmonic acid; C030737:indoleacetic acid; D000040:Abscisic Acid; C007842:gibberellic acid; C023623:brassinolide