Qian Tang1, Peng Yu1, Molly Tillmann1, Jerry D Cohen2, Janet P Slovin3. 1. Department of Horticultural Science and Microbial and Plant Genome Institute, University of Minnesota, Alderman Hall, 1970 Folwell Avenue, Saint Paul, MN, 55108, USA. 2. Department of Horticultural Science and Microbial and Plant Genome Institute, University of Minnesota, Alderman Hall, 1970 Folwell Avenue, Saint Paul, MN, 55108, USA. cohen047@umn.edu. 3. USDA/ARS Genetic Improvement of Fruit and Vegetables Laboratory, 10300 Baltimore Avenue, Beltsville, MD, 20705, USA. janet.slovin@ars.usda.gov.
Abstract
MAIN CONCLUSION: Indole-3-acetylaspartate and indole-3-acetylglutamate are the stored auxin amino acid conjugates of the achene of the diploid strawberry and serve as sources of auxin during seedling growth. The edible part of the strawberry, a pseudocarp, has long been known to enlarge in response to auxin produced by the developing achenes, the botanical true fruit. Auxin homeostasis involves a complex interaction between biosynthesis, conjugate formation and hydrolysis, catabolism and transport. Strawberry tissues are capable of synthesizing auxin conjugates, and transcriptome data support the expression of genes involved in IAA conjugate formation and hydrolysis throughout embryo development and subsequent seedling growth. Using a highly sensitive and selective mass spectrometric method, we identified all the low molecular weight indole-auxin amino acid conjugates in achenes of F. vesca as consisting of indole-3-acetylaspartate (IAasp) and indole-3-acetylglutamate (IAglu). In contrast to what has been proposed to occur in Arabidopsis, we determined that IAasp and IAglu are hydrolyzed by seedlings to provide a source of free IAA for growth.
MAIN CONCLUSION: Indole-3-acetylaspartate and indole-3-acetylglutamate are the stored auxin amino acid conjugates of the achene of the diploid strawberry and serve as sources of auxin during seedling growth. The edible part of the strawberry, a pseudocarp, has long been known to enlarge in response to auxin produced by the developing achenes, the botanical true fruit. Auxin homeostasis involves a complex interaction between biosynthesis, conjugate formation and hydrolysis, catabolism and transport. Strawberry tissues are capable of synthesizing auxin conjugates, and transcriptome data support the expression of genes involved in IAA conjugate formation and hydrolysis throughout embryo development and subsequent seedling growth. Using a highly sensitive and selective mass spectrometric method, we identified all the low molecular weight indole-auxin amino acid conjugates in achenes of F. vesca as consisting of indole-3-acetylaspartate (IAasp) and indole-3-acetylglutamate (IAglu). In contrast to what has been proposed to occur in Arabidopsis, we determined that IAasp and IAglu are hydrolyzed by seedlings to provide a source of free IAA for growth.
Authors: Miguel A Uc-Chuc; Cleyre Pérez-Hernández; Rosa M Galaz-Ávalos; Ligia Brito-Argaez; Víctor Aguilar-Hernández; Víctor M Loyola-Vargas Journal: Int J Mol Sci Date: 2020-07-03 Impact factor: 5.923
Authors: Minmin Du; Firas Bou Daher; Yuanyuan Liu; Andrew Steward; Molly Tillmann; Xiaoyue Zhang; Jeh Haur Wong; Hong Ren; Jerry D Cohen; Chuanyou Li; William M Gray Journal: Sci Adv Date: 2022-01-12 Impact factor: 14.136