Aidi Zhang1,2, Qiuyun Zhang3, Jianzhao Li4, Hansheng Gong5,6, Xinguang Fan5, Yanqing Yang5, Xiaofen Liu3, Xueren Yin7. 1. School of Food Engineering, Ludong University, Yantai, Shandong, 264025, People's Republic of China. aidi2012@126.com. 2. BioNanotechnology Institute, Ludong University, Yantai, Shandong, 264025, People's Republic of China. aidi2012@126.com. 3. College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China. 4. School of Agriculture, Ludong University, Yantai, Shandong, 264025, People's Republic of China. 5. School of Food Engineering, Ludong University, Yantai, Shandong, 264025, People's Republic of China. 6. BioNanotechnology Institute, Ludong University, Yantai, Shandong, 264025, People's Republic of China. 7. College of Agriculture & Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou, 310058, People's Republic of China. xuerenyin@zju.edu.cn.
Abstract
BACKGROUND: Aroma is an important organoleptic quality for fruit and has a large influence on consumer preference. Kiwifruit esters undergo rapid and substantial changes contributing to the flavor during fruit ripening. Part of enzymes and their coding genes have been indicated potential candidates for flavor-related esters synthesis. However, there still exist obvious gaps in the biosynthetic pathways of esters and the mechanisms regulating ester biosynthesis in kiwifruit remain unknown. RESULTS: Using gas chromatography-mass spectrometry (GC-MS), volatile compounds of kiwifruit were quantified in response to ethylene (ETH, 100 μl/l, 24 h, 20 °C) and 1-methylcyclopropene (1-MCP, 1 μl/l, 24 h, 20 °C). The results indicated that esters showed the most substantial changes enhanced by ethylene and were inhibited by 1-MCP. Correlations between RNA-seq results and concentrations of esters, constructed using Weighted Gene Co-Expression Network Analysis (WGCNA) indicated that three structural genes (fatty acid desaturase, AdFAD1; aldehyde dehydrogenase, AdALDH2; alcohol acyltransferase, AdAT17) had similar expression patterns that paralled the changes in total ester content, and AdFAD1 transcripts exhibited the highest correlation. In order to search for potential regulators for ester biosynthesis, 14 previously reported ethylene-responsive transcription factors (TFs) were included in the correlation analysis with esters and their biosynthetic genes. Using dual-luciferase assay, the in vivo regulatory activities of TFs on ester biosynthetic gene promoters were investigated and the results indicated that AdNAC5 and AdDof4 (DNA binding with one finger) trans-activated and trans-suppressed the AdFAD1 promoter. CONCLUSIONS: The present study advanced the molecular basis of ripening-related ester biosynthesis in kiwifruit by identifying three biosynthetic related genes AdFAD1, AdALDH2 and AdAT17 by transcriptome analysis, and highlighted the function of two TFs by transactivation studies.
BACKGROUND: Aroma is an important organoleptic quality for fruit and has a large influence on consumer preference. Kiwifruitesters undergo rapid and substantial changes contributing to the flavor during fruit ripening. Part of enzymes and their coding genes have been indicated potential candidates for flavor-related esters synthesis. However, there still exist obvious gaps in the biosynthetic pathways of esters and the mechanisms regulating ester biosynthesis in kiwifruit remain unknown. RESULTS: Using gas chromatography-mass spectrometry (GC-MS), volatile compounds of kiwifruit were quantified in response to ethylene (ETH, 100 μl/l, 24 h, 20 °C) and 1-methylcyclopropene (1-MCP, 1 μl/l, 24 h, 20 °C). The results indicated that esters showed the most substantial changes enhanced by ethylene and were inhibited by 1-MCP. Correlations between RNA-seq results and concentrations of esters, constructed using Weighted Gene Co-Expression Network Analysis (WGCNA) indicated that three structural genes (fatty acid desaturase, AdFAD1; aldehyde dehydrogenase, AdALDH2; alcohol acyltransferase, AdAT17) had similar expression patterns that paralled the changes in total ester content, and AdFAD1 transcripts exhibited the highest correlation. In order to search for potential regulators for ester biosynthesis, 14 previously reported ethylene-responsive transcription factors (TFs) were included in the correlation analysis with esters and their biosynthetic genes. Using dual-luciferase assay, the in vivo regulatory activities of TFs on ester biosynthetic gene promoters were investigated and the results indicated that AdNAC5 and AdDof4 (DNA binding with one finger) trans-activated and trans-suppressed the AdFAD1 promoter. CONCLUSIONS: The present study advanced the molecular basis of ripening-related ester biosynthesis in kiwifruit by identifying three biosynthetic related genes AdFAD1, AdALDH2 and AdAT17 by transcriptome analysis, and highlighted the function of two TFs by transactivation studies.
Authors: Edwige J F Souleyre; Niels J Nieuwenhuizen; Mindy Y Wang; Robert A Winz; Adam J Matich; Nadeesha R Ileperuma; Haidee Tang; Samantha J Baldwin; Tianchi Wang; Blake W List; Kirsten A Hoeata; Elizabeth A Popowski; Ross G Atkinson Journal: Plant Physiol Date: 2022-09-28 Impact factor: 8.005