Location: Grape Genetics Research Unit (GGRU)
Title: Transcriptome analysis reveals a potential novel role of VvAP1 in regulation of the developmental fate of anlagens in grapevineAuthor
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ARRO, JIE - Former ARS Employee |
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Yang, Yingzhen |
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SONG, GUOQING - Michigan State University |
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COUSINS, PETER - E & J Gallo Winery |
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Liu, Zongrang |
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Zhong, Gan-Yuan |
Submitted to: Fruit Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/27/2023 Publication Date: 3/4/2024 Citation: Arro, J., Yang, Y., Song, G., Cousins, P., Liu, Z., Zhong, G. 2024. Transcriptome analysis reveals a potential novel role of VvAP1 in regulation of the developmental fate of anlagens in grapevine. Fruit Research. https://doi.org/10.48130/frures-0024-0004. DOI: https://doi.org/10.48130/frures-0024-0004 Interpretive Summary: A dwarf mutant vine, named as 'Pixie', was found to flower continuously with many inflorescences and few tendrils. The mutant resulted from a mutation in a gene named as 'VvDELLA'. Why the mutant produces more inflorescences than tendrils is not known. We conducted a gene expression study and compared the expression profiles of wild type and several grapevines of different genetic backgrounds carrying the mutation. We concluded that flower regulator genes VvAP1 and VvTFL1a promotes anlagens (undifferentiated primordia) to develop tendrils while VvLFY favors inflorescences, and their ratio likely dictates the developmental fate of anlagens to tendrils or inflorescences. Technical Abstract: Grapevine shoot meristem contains undifferentiated primordia known as anlagen, which can develop into either inflorescences or tendrils depending on vine age, growth status, hormone balance, and other factors. Interestingly, a gain-of-function mutation in the DELLA domain of VvDELLA1 (or VvGAI1) in a dwarf mutant grape named as “Pixie” virtually disrupts the normal developmental course of anlagen and reroutes tendril-bounded anlagen toward inflorescence development even at the juvenile stage. To understand the underlying mechanism, we compared the transcriptome profiles of Pinot Meunier from which Pixie was derived, Pixie and three other grape cultivars carrying the same DELLA mutation derived from Pixie. Our findings revealed significant mis-regulation of hundreds of genes, profoundly reshaping both transcriptome landscapes and regulatory pathways in the mutant grapes. Interestingly, VvAP1 which is a central positive flower regulator in annuals was unexpectedly co-downregulated with VvTFL1a, a flowering repressor. We also found several other key flower regulators which were either up-regulated (e.g. VvFT, VvLFY) or downregulated (e.g. VvSOC1s) in all four mutant grapes, although the overall effect was moderate. These findings, along with the previous identification of tendril-specific expression of VvAP1 and inflorescence-specific expression of VvLFY, support that VvAP1 together with VvTFL1a promotes anlagens to develop tendrils, whereas VvLFY favors inflorescences formation. The balance between these factors, particularly the abundance of VvAP1 transcripts, ultimately dictates whether anlagens develop into tendrils or inflorescences. |