N-Acylethanolamine Metabolism Interacts with Abscisic Acid Signaling in Arabidopsis thaliana Seedlings[W][OA]

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

Agricultural Research Bulletins, Nos. 489-521

Volume 34, Bulletins 489-521. (489) Ownership of Iowa's Farmland; (490) Identification and Measurement of Inefficiencies in Leasing Systems; (491) Comparison of Resource Returns of Well-Organized Iowa Farms with Selected Nonfarm Opportunities; (492) Iowa Livestock Producers' Choice of Markets; (493) Methodology of Programming Small Watershed Development; (494) North Central Regional Potassium Studies: I. Field Studies with Alfalfa; (495) Organoleptic, Chemical, Physical and Microscopic Characteristics of Muscles in Eight Beef Carcasses, Differing in Age of Animal, Carcass Grade and Extent of Cooking; (496) Specialization and Pork Production Methods in Relation to Over-All Farm Resource Use and Integration; (497) Maternal Employment, Family Relations and Selected Personality, School-Related and Social-Development Characteristics of Children; (498) Soil Erosion Control in Western Iowa: Progress and Problems; (499) Response of Corn Yields in a Planosol Soil to Surface Drainage, Cropping System and Variable Fertilizer Treatments; (500) Description and Measurement of Rates of Early Mortality in the Pig; (501) Appraisal of the Federal Feed--Grains Programs; (502) Production, Income and Resource Changes from Farm Consolidation; (503) North Central Regional Potassium Studies; (504) Farm Size and Cost Relationships in Relation to Recent Machine Technology; (505) Poultry Supply Functions (The Relation of Technical Change to Output of Eggs, Broilers and Turkeys); (506) Derivation of Hydrographs for Small Watersheds from Measurable Physical Characteristics; (507) Short-Run Corn Supply and Fertilizer Demand Functions Based on Production Functions Derived from Experimental Data: a Static Analysis; (508) Occupational Plans of Iowa Farm Boys; (509) Factors Related to Employment of Wives in a Rural Iowa County; (510) Factors Related to Interreligious Marriages in Iowa, 1953-57; (511) Interregional Competition and Prospective Shifts in the Location of Livestock Slaughter; (512) Survival Rates Among Religiously Homogamous and Interreligious Marriages; (513) Effects of Light and Soil Moisture on Forest Tree Seedling Establishment; (514) Analysis of Direct-Payment Methods for Hogs to Increase Hog Producers' Incomes; (515) Distributed Lag Inventory Analyses; (516) Migration and Adjustment of Farm and Nonfarm Families and Adolescents in Cedar Rapids, Iowa; (517) Beef-Cattle Production Functions in Forage Utilization; (518) Production Functions and Methods of Specifying Optimum Fertilizer Use Under Various Uncertainty Conditions for Hay; (519) Profit-Maximizing Plans for Soil-Conserving Farming in the Spring Valley Creek Watershed in Southwest Iowa; (520) Estimation of Soil Moisture Under Corn; (521) Regional Changes in Grain Production: An Application of Spatial Linear Programming</p