| Title: | Transcriptional and epigenetic analysis reveals that NAC transcription factors regulate fruit flavor ester biosynthesis |
| Author(s): | Cao X; Wei C; Duan W; Gao Y; Kuang J; Liu M; Chen K; Klee H; Zhang B; |
| Address: | "Laboratory of Fruit Quality Biology/Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, China. Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University, Guangzhou, 510642, China. Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China. Horticultural Sciences, Plant Innovation Center, Genetic Institute, University of Florida, Gainesville, FL, 32611, USA" |
| ISSN/ISBN: | 1365-313X (Electronic) 0960-7412 (Linking) |
| Abstract: | "Flavor-associated volatile chemicals make major contributions to consumers' perception of fruits. Although great progress has been made in establishing the metabolic pathways associated with volatile synthesis, much less is known about the regulation of those pathways. Knowledge of how those pathways are regulated would greatly facilitate efforts to improve flavor. Volatile esters are major contributors to fruity flavor notes in many species, providing a good model to investigate the regulation of volatile synthesis pathways. Here we initiated a study of peach (Prunus persica L. Batsch) fruits, and identified that the alcohol acyltransferase PpAAT1 contributes to ester formation. We next identified the transcription factor (TF) PpNAC1 as an activator of PpAAT1 expression and ester production. These conclusions were based on in vivo and in vitro experiments and validated by correlation in a panel of 30 different peach cultivars. Based on homology between PpNAC1 and the tomato (Solanum lycopersicum) TF NONRIPENING (NOR), we identified a parallel regulatory pathway in tomato. Overexpression of PpNAC1 enhances ripening in a nor mutant and restores synthesis of volatile esters in tomato fruits. Furthermore, in the NOR-deficient mutant tomatoes generated by CRISPR/Cas9, lower transcript levels of SlAAT1 were detected. The apple (Malus domestica) homolog MdNAC5 also stimulates MdAAT1 expression via binding to this gene's promoter. In addition to transcriptional control, epigenetic analysis showed that increased expression of NACs and AATs is associated with removal of the repressive mark H3K27me3 during fruit ripening. Our results support a conserved molecular mechanism in which NAC TFs activate ripening-related AAT expression, which in turn catalyzes volatile ester formation in multiple fruit species" |
| Keywords: | "*Epigenesis, Genetic Esters/*metabolism *Food Quality Fruit/*metabolism *Gene Expression Regulation, Plant Solanum lycopersicum/*metabolism Malus/*metabolism Prunus persica/*metabolism Transcription Factors/*metabolism/physiology Volatile Organic Compound;" |
| Notes: | "MedlineCao, Xiangmei Wei, Chunyan Duan, Wenyi Gao, Ying Kuang, Jianfei Liu, Mingchun Chen, Kunsong Klee, Harry Zhang, Bo eng Research Support, Non-U.S. Gov't England 2021/02/18 Plant J. 2021 May; 106(3):785-800. doi: 10.1111/tpj.15200. Epub 2021 Apr 8" |
