ITRAQ-based quantitative proteomic analysis of salt stress in Spica Prunellae

Zixiu Liu,Cuihua Chen,Chengcheng Wang,Lisi Zou,Ying Yan,Xunhong Liu,Hui Zhao

doi:10.1038/s41598-019-46043-9

Abstract

Spica Prunellae is an important Chinese herbal medicine. Because of its good curative effect on various diseases, this herb is consumed in large quantities in clinical applications. The metabolites of Spica Prunellae are known to change under salt stress; however, the difference in protein levels of Spica Prunellae between saline and normal conditions is unclear. In this study, we used proteomics techniques to identify differentially expressed proteins in Spica Prunellae under different saline conditions. (iTRAQ) MS/MS was used to detect statistically significant changes in protein between salt stress and normal conditions. Ultimately, we detected 1,937 proteins, 89 of which were detected in two different comparison. Based on GO, STRING and KEGG analyses, 35 significantly differentially expressed proteins were selected for further analysis. The results of functional and signal pathway analyses indicated that the cellular protein and carbohydrate metabolism of Spica Prunellae was weaker, calcium ion transport was higher, photosynthesis was higher, and protein production was faster under saline conditions than under normal conditions. This study provides useful information for studying the causes of differences in secondary metabolites in Spica Prunellae under salt stress and the protein mechanisms related to their quality.

Highlights

Soil salinity is a major external environmental stressor of plants worldwide because it has a very strong negative effect on plant growth, development and production
The expression level of proteins across the genome is generally stable under normal conditions, it always changes in response to a change in environmental conditions, such as salt stress[24]
Our results suggested that two 14-3-3-like protein species were significantly upregulated under salt stress especially in the Na100 treatment, which was consistent with the results of a previous study on salt-stressed sugar beet[31]

Summary

Introduction

Soil salinity is a major external environmental stressor of plants worldwide because it has a very strong negative effect on plant growth, development and production. Plants have developed a series of tolerance mechanisms for growth under harmful conditions This tolerance depends primarily on a variety of biochemical processes that lead to the production of compatible permeants, antioxidants, transporters and specific proteins that control salt damage[3]. It is very important to study the salt tolerance mechanism of Spica Prunellae to increase the yield and quality of this important herb. Proteomics-based technologies have been widely used to identify proteins responsible for salt tolerance in several crops, such as cotton[17], cucumber[18] and wheat[19], promoting advancements in the study of molecular activities under salt stress.

Methods

Results

Discussion

Conclusion