Combination of RNA-Seq transcriptomics and iTRAQ proteomics reveal the mechanism involved in fresh-cut yam yellowing

Shuang Guo,Yan Zhang,Yue Ma,Dan Wang,Xiaoyan Zhao

doi:10.1038/s41598-021-87423-4

Shuang Guo, Yan Zhang + Show 3 more

Open Access

https://doi.org/10.1038/s41598-021-87423-4

Copy DOI

Abstract

The aim of this study was to examine the regulation of transcriptomics and proteomics related to the yellowing of fresh-cut yams after storage. The comparison of yellow fresh-cut yam (YFY) vs. white fresh-cut yam (control) revealed 6894 upregulated and 6800 downregulated differentially expressed genes along with 1277 upregulated and 677 downregulated differentially expressed proteins. The results showed that the total carotenoids, flavonoids, and bisdemethoxycurcumin in YFY were higher than in the control due to the significant up-regulation of critical genes in the carotenoid biosynthesis pathway, flavonoid biosynthesis pathway, and stilbenoid, diarylheptanoid, and gingerol biosynthesis pathway. In addition, the tricarboxylic acid cycle and phenylpropanoid biosynthesis were both enhanced in YFY compared to the control, providing energy and precursors for the formation of yellow pigments. The results suggest that the synthesis of yellow pigments is regulated by critical genes, which might explain the yellowing of fresh-cut yam after storage.

Highlights

Chinese yam (Dioscorea opposita Thunb.) is a well-known vegetable with high nutritional and medicinal values[1], which contains mainly proteins, sugars, vitamins, fats, choline, amylase, iodine, iron, calcium, phosphorus, and other trace elements that are indispensable to the human body
RNA sequencing (RNA-Seq) is a method for transcript quantification that allows the more precise measurement of transcript levels and their isoforms compared to other approaches
The yellow fresh-cut yam (YFY) samples exhibited decreased L* and a* values but a significantly increased b* value, which is the most important index for evaluating yam yellowing, indicating that yellowing occurred during storage

Summary

Introduction

Chinese yam (Dioscorea opposita Thunb.) is a well-known vegetable with high nutritional and medicinal values[1], which contains mainly proteins, sugars, vitamins, fats, choline, amylase, iodine, iron, calcium, phosphorus, and other trace elements that are indispensable to the human body. Besides with the convenient eating characteristics, processing of fresh-cut Chinese yam can provide a good way to solve the allergy issues. Our recent study revealed that fresh-cut yam turns yellow during storage, which is attributed to various yellow substances including bisdemethoxycurcumin and other unknown c ompounds[6,7]. This yellowing process is different from the browning process during storage, which results from the polyphenol oxidase-catalyzed oxidation of phenolic compounds to o rthoquinones[8]. We carried out transcriptomic and proteomic profiling to identify changes in the expression levels of critical genes and proteins. The results provide valuable information for the preservation of yams

Objectives

Methods

Results

Conclusion