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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #356541

Research Project: Nutritional Metabolism in Mothers, Infants, and Children

Location: Children's Nutrition Research Center

Title: Effect of acyl activating enzyme (AAE) 3 on the growth and development of Medicago truncatula

item CHENG, NINGHUI - Children'S Nutrition Research Center (CNRC)
item FOSTER, JUSTIN - Baylor College Of Medicine
item MYSORE, KIRAN - Noble Research Institute
item WEN, JIANGQI - Noble Research Institute
item RAO, XIAOLAN - University Of North Texas
item Nakata, Paul

Submitted to: Biochemical and Biophysical Research Communications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2018
Publication Date: 9/20/2018
Citation: Cheng, N., Foster, J., Mysore, K., Wen, J., Rao, X., Nakata, P.A. 2018. Effect of acyl activating enzyme (AAE) 3 on the growth and development of Medicago truncatula. Biochemical and Biophysical Research Communications. 505:255-260.

Interpretive Summary: Plant scientists have been avidly working to discover new strategies to increase crop resistance to oxalate-secreting fungal pathogens. These fungal pathogens produce oxalate as a plant toxin that is required by the fungus for plant infection. Such fungi are responsible for major crop losses each year. Recently, we identified a novel pathway of oxalate degradation in plants. Before we can go about manipulating this pathway to increase a plants resistance to oxalate-secreting pathogens we need to gain better understanding of the enzymes that make up this pathway and whether these enzyme are needed by the plant for other functions. In this study we study plants expressing different amounts of an enzyme catalyzing the first step in a novel pathway of oxalate degradation. Biological analysis revealed that the plants need this enzyme in order to grow and set seed normally. This enzyme is also important for normal germination of the seeds. In addition, we found that these different growth and seed features can be separated based on how much of this enzyme is expressed. Such information is necessary before rational strategies can be designed to improve plant resistance to certain pathogens.

Technical Abstract: The Acyl-activating enzyme (AAE) 3 gene encodes an oxalyl-CoA synthetase that catalyzes the conversion of oxalate to oxalyl-CoA in a CoA and ATP-dependent manner. Although the biochemical activity of AAE3 has been established, its biological role in plant growth and development remains unclear. To advance our understanding of the role of AAE3 in plant growth and development we report here the characterization of two Medicago truncatula AAE3 (Mtaae3) mutants. Characterization of a Mtaae3 RNAi mutant revealed an accumulation of calcium oxalate crystals and increased seed permeability. These phenotypes were also exhibited by the Arabidopsis thaliana aae3 (Ataae3) mutants. Unlike the Ataae3 mutants; the Mtaae3 RNAi mutant did not show a reduction in vegetative growth, decreased seed germination, or increased seed calcium concentration. In an effort to clarify these phenotypic differences a Mtaae3 Tnt1 mutant was identified and characterized. This Mtaae3 Tnt1 mutant displayed the reduced vegetative growth, decreased seed germination, and increased seed calcium concentration as well as the accumulation of calcium oxalate crystals and increased seed permeability as found in the Ataae3. Overall, the results presented here show the importance of AAE3 in the growth and development of plants. In addition, this study highlights the ability to separate specific growth and development phenotypes based on the level of AAE3 gene expression.