Gene coexpression network analysis of fruit transcriptomes uncovers a possible mechanistically distinct class of sugar/acid ratio-associated genes in sweet orange

BMC Plant Biology

Research Article

Yihong Zhao¹  Minghao Cao²  Jian Zheng²  Liang Qiao²  Zhi-Liang Zheng³ 

[1] Division of Biostatistics, Department of Child and Adolescent Psychiatry, New York University Langone Medical Center, 10016, New York, NY, USA;Plant Nutrient Signaling and Fruit Quality Improvement Laboratory, National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Beibei, 400712, Chongqing, China;Plant Nutrient Signaling and Fruit Quality Improvement Laboratory, National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Beibei, 400712, Chongqing, China;Department of Biological Sciences, Lehman College, City University of New York, 10468, Bronx, NY, USA;

关键词: Citrus;    Orange;    Fruit;    Acids;    Sugars;    Sugar/acid ratio;    Transcriptome;    Gene networks;   

DOI  :  10.1186/s12870-017-1138-8

 received in 2017-03-24, accepted in 2017-10-22,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundThe ratio of sugars to organic acids, two of the major metabolites in fleshy fruits, has been considered the most important contributor to fruit sweetness. Although accumulation of sugars and acids have been extensively studied, whether plants evolve a mechanism to maintain, sense or respond to the fruit sugar/acid ratio remains a mystery. In a prior study, we used an integrated systems biology tool to identify a group of 39 acid-associated genes from the fruit transcriptomes in four sweet orange varieties (Citrus sinensis L. Osbeck) with varying fruit acidity, Succari (acidless), Bingtang (low acid), and Newhall and Xinhui (normal acid).ResultsWe reanalyzed the prior sweet orange fruit transcriptome data, leading to the identification of 72 genes highly correlated with the fruit sugar/acid ratio. The majority of these sugar/acid ratio-related genes are predicted to be involved in regulatory functions such as transport, signaling and transcription or encode enzymes involved in metabolism. Surprisingly, only three of these sugar/acid ratio-correlated genes are weakly correlated with sugar level and none of them overlaps with the acid-associated genes. Weighted Gene Coexpression Network Analysis (WGCNA) has revealed that these genes belong to four modules, Blue, Grey, Brown and Turquoise, with the former two modules being unique to the sugar/acid ratio control.ConclusionOur results indicate that orange fruits contain a possible mechanistically distinct class of genes that may potentially be involved in maintaining fruit sugar/acid ratios and/or responding to the cellular sugar/acid ratio status. Therefore, our analysis of orange transcriptomes provides an intriguing insight into the potentially novel genetic or molecular mechanisms controlling the sugar/acid ratio in fruits.

【 授权许可】

CC BY   
© The Author(s). 2017