N-Acylethanolamine metabolism interacts with abscisic acid signaling in Arabidopsis thaliana seedlings.
N-Acylethanolamines (NAEs) are bioactive acylamides that are present in a wide range of organisms. In plants, NAEs are generally elevated in desiccated seeds, suggesting that they may play a role in seed physiology. NAE and abscisic acid (ABA) levels were depleted during seed germination, and both metabolites inhibited the growth of Arabidopsis thaliana seedlings within a similar developmental window. Combined application of low levels of ABA and NAE produced a more dramatic reduction in germination and growth than either compound alone. Transcript profiling and gene expression studies in NAE-treated seedlings revealed elevated transcripts for a number of ABA-responsive genes and genes typically enriched in desiccated seeds. The levels of ABI3 transcripts were inversely associated with NAE-modulated growth. Overexpression of the Arabidopsis NAE degrading enzyme fatty acid amide hydrolase resulted in seedlings that were hypersensitive to ABA, whereas the ABA-insensitive mutants, abi1-1, abi2-1, and abi3-1, exhibited reduced sensitivity to NAE. Collectively, our data indicate that an intact ABA signaling pathway is required for NAE action and that NAE may intersect the ABA pathway downstream from ABA. We propose that NAE metabolism interacts with ABA in the negative regulation of seedling development and that normal seedling establishment depends on the reduction of the endogenous levels of both metabolites.
Teaster
Neal D
ND
Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, Texas 76203, USA.
Motes
Christy M
CM
Tang
Yuhong
Y
Wiant
William C
WC
Cotter
Matthew Q
MQ
Wang
Yuh-Shuh
YS
Kilaru
Aruna
A
Venables
Barney J
BJ
Hasenstein
Karl H
KH
Gonzalez
Gabriel
G
Blancaflor
Elison B
EB
Chapman
Kent D
KD
D000040:Abscisic Acid / Q000378:metabolism* / Q000494:pharmacology; D000222:Adaptation, Physiological / Q000187:drug effects; D000581:Amidohydrolases / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D004983:Ethanolamines / Q000378:metabolism* / Q000494:pharmacology; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018525:Germination / Q000187:drug effects; D007700:Kinetics; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000187:drug effects; D000099252:Fatty Acid Amide Hydrolases
D000040:Abscisic Acid; D000581:Amidohydrolases; D029681:Arabidopsis Proteins; D004983:Ethanolamines; D012333:RNA, Messenger; D014157:Transcription Factors; D000099252:Fatty Acid Amide Hydrolases; C091601:ABI3 protein, Arabidopsis; C022203:N-acylethanolamines