Comparative physiological and proteomic analysis indicates lower shock response to drought stress conditions in a self-pollinating perennial ryegrass.

Fatemeh Raeisi Vanani,Lisa Winner,Mohammad R Sabzalian,Fariba Dehghanian,Leila Shabani,Tong Zhang

doi:10.1371/journal.pone.0234317

Fatemeh Raeisi Vanani, Lisa Winner + Show 4 more

Open Access

https://doi.org/10.1371/journal.pone.0234317

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Abstract

We investigated the physiological and proteomic changes in the leaves of three Lolium perenne genotypes, one Iranian putative self-pollinating genotype named S10 and two commercial genotypes of Vigor and Speedy, subjected to drought stress conditions. The results of this study indeed showed higher RWC (relative water content), SDW (shoot dry weight), proline, ABA (abscisic acid), nitrogen and amino acid contents, and antioxidant enzymes activities of S10 under drought stress in comparison with the two other genotypes. A total of 915 proteins were identified using liquid chromatography-mass spectrometry (LC/MS) analysis, and the number of differentially abundant proteins between normal and stress conditions was 467, 456, and 99 in Vigor, Speedy, and S10, respectively. Proteins involved in carbon and energy metabolism, photosynthesis, TCA cycle, redox, and transport categories were up-regulated in the two commercial genotypes. We also found that some protein inductions, including those involved in amino acid and ABA metabolisms, aquaporin, HSPs, photorespiration, and increases in the abundance of antioxidant enzymes, are essential responses of the two commercial genotypes to drought stress. In contrast, we observed only slight changes in the protein profile of the S10 genotype under drought stress. Higher homozygosity due to self-pollination in the genetic background of the S10 genotype may have led to a lower variation in response to drought stress conditions.

Highlights

Our results show that the abundance of glutamine synthetase (GS) and GOGAT decreased in the two commercial genotypes under stress, but no change was observed in the abundance of these two enzymes in the S10 genotype
The results of this study showed that relative water content (RWC) and shoot dry weight (SDW), proline, Abscisic acid (ABA), N, and amino acid contents, and antioxidant enzyme activities were significantly higher in the drought-tolerant genotype of S10 under drought stress in comparison with the two commercial genotypes
Results of the proteomics analysis revealed significant differences between the examined genotypes of Lolium under drought stress conditions (Fig 7), and this result seems to be related to the higher ability of the S10 genotype in response to drought stress

Summary

Introduction

Norris [3] and Turgeon [4] mentioned that perennial ryegrass is a drought-susceptible grass species, there seems to be a noticeable genotypic variation for drought stress responses. Many cool-season grasses can resist moderate drought and maintain their aerial growth to avoid and tolerate leaf dehydration. They may be equipped with the strategies facilitating their survival of severe drought, mainly associated with dehydration avoidance and tolerance, which primarily occurs in meristematic tissues [7]. In some species and genotypes of grasses, summer dormancy is another strategy that confers efficient survival of meristematic tissues through dehydration avoidance and tolerance [8]

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Discussion

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