Identification of Candidate Genes and Proteins Related to the Production of ROS in Korla Pear Fruit

Kuerban Tusong,Juan Xu,Jixun Wang,Aisajan Mamat

doi:10.11648/j.plant.20210901.11

Abstract

Korla fragrant pear (<i>P. sinkiangensis</i> Yü) is a landrace selected from a hybrid pear species of Xinjiang Autonomous Region in China. However, recently the formation of rough skin fruits is one of the main factors reducing fruit quality. In this study, parallel analyses of transcriptomic and proteomic data of Korla pear fruits from the three developmental stages (20, 50 and 80 days after flowering, DAF) were carried out by using RNA sequencing (RNA-seq) and tandem mass tags technology (TMT), to identify differential genes and proteins that may regulate reactive oxygen species (ROS) generation during stone cell differentiation period. In total, 42893 transcripts and 7904 proteins were acquired. Among them, 74 differentially expressed genes (DEGs) and 40 correlated proteins were identified as ROS related genes and proteins, including 15 differentially accumulated proteins (DAPs). These include genes and proteins related to the ROS production in the apoplast (24 DEGs and seven DAPs), mitochondria (23 DEGs and two DAPs), peroxisome (10 DEGs and four DAPs), and during fatty acid degradation (15 DEGs and two DAPs), respectively. All of DEGs and DAPs that related to apoplastic ROS production and some of DEGs and DAPs that related to ROS production in peroxisome and fatty acid metabolism pathways were abundantly expressed during the critical period of stone cell differentiation (20 DAF). To sum up, apoplast might be the main source of ROS production that participate in the process of stone cell differentiation in pear fruits. In addition, peroxisome and fatty acid metabolism pathways also produce certain amount of ROS during this process.

Highlights

Korla fragrant pear (Pyrus sinkiangensis Yü) is one of the characteristic fruit trees in Xinjiang, China
In order to identify the candidate genes and proteins which were related to reactive oxygen species (ROS) production in Korla pear fruit, transcriptome and proteome analysis were performed on fruit samples from three different developmental stages
Among the differentially expressed genes (DEGs) encoding ACOX, except for one transcript (Entrez ID: 103967278), expression levels of other four DEGs were low in early fruits, as the fruits growing the expression levels of these genes gradually reached their picks in the late stage (80 days after flowering (DAF)), the expression fold change of these genes in different stages ranged from 2.63 to 10.43. These results indicate that ROS produced in peroxisome during the critical period of stone cell differentiation (0 to 50 DAF) were mainly derived from the process of glycolic acid cycle, while ROS produced in peroxisome in late stage of fruit development were mainly comes from the β-oxidation of fatty acids, which is closely related to the conversion of fat to sugar and aroma components, this process may be related to the accumulation of sugars and aroma components in pear fruits

Summary

Introduction

Korla fragrant pear (Pyrus sinkiangensis Yü) is one of the characteristic fruit trees in Xinjiang, China. In recent years, the content of stone cells in Korla pear fruits has increased and causing the formation of rough skin on fruit surface, which leads to degradation of varieties and the reducing of fruit quality. Previous studies showed that the process of stone cell differentiation is in nature a process of secondary thickening of cell walls [1, 2]. Lignin is the main structural component of secondary of cell wall, so as the stone cells [3]. We presumed that ROS may act as a signal molecule to activate PCD in some specific cells, lignin deposition in the secondary walls of cells that went through apoptosis to form sclerotic cells. In order to reveal this scientific inference, in this study, parallel analyses of the transcriptome and proteome of Korla pear fruits from the three developmental

Methods

Results

Discussion

Conclusion