1. AUXIN RESPONSE FACTOR 2 mediates repression of strawberry receptacle ripening via auxin-ABA interplay.
- Author
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Li BJ, Shi YN, Xiao YN, Jia HR, Yang XF, Dai ZR, Sun YF, Shou JH, Jiang GH, Grierson D, and Chen KS
- Subjects
- Plant Growth Regulators metabolism, Promoter Regions, Genetic genetics, Dioxygenases metabolism, Dioxygenases genetics, Transcription Factors metabolism, Transcription Factors genetics, Fragaria genetics, Fragaria metabolism, Fragaria growth & development, Indoleacetic Acids metabolism, Plant Proteins metabolism, Plant Proteins genetics, Abscisic Acid metabolism, Gene Expression Regulation, Plant, Fruit metabolism, Fruit genetics, Fruit growth & development
- Abstract
Cultivated strawberry (Fragaria × ananassa) is a popular, economically important fruit. The ripening of the receptacle (pseudocarp), the main edible part, depends on endogenously produced abscisic acid (ABA) and is suppressed by the high level of auxin produced from achenes (true fruit) during early development. However, the mechanism whereby auxin regulates receptacle ripening through inhibiting ABA biosynthesis remains unclear. Here, we identified AUXIN RESPONSE FACTOR 2 (FaARF2), which showed decreased expression with reduced auxin content in the receptacle, leading to increased ABA levels and accelerated ripening. Dual-luciferase, yeast one-hybrid, and electrophoretic mobility shift assays demonstrated that FaARF2 could bind to the AuxRE element in the promoter of 9-CIS-EPOXYCAROT-ENOID DIOXYGENASE 1 (FaNCED1), a key ABA biosynthetic gene, to suppress its transcriptional activity. Transiently overexpressing FaARF2 in the receptacles decreased FaNCED1 expression and ABA levels, resulting in inhibition of receptacle ripening and of development of quality attributes, such as pigmentation, aroma, and sweetness. This inhibition caused by overexpressing FaARF2 was partially recovered by the injection of exogenous ABA; conversely, transient silencing of FaARF2 using RNA interference produced the opposite results. The negative targeting of FaNCED1 by FaARF2 is a key link between auxin-ABA interactions and regulation of strawberry ripening., Competing Interests: Conflict of interest statement. The authors declare no competing interests., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists.)
- Published
- 2024
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