Genome-Wide Analysis and Expression Profiling of Rice Hybrid Proline-Rich Proteins in Response to Biotic and Abiotic Stresses, and Hormone Treatment.

Ritu Kapoor,Preeti Arya,Priyanka Jain,Tilak Raj Sharma,Kashmir Singh,Gulshan Kumar,Rajdeep Jaswal

doi:10.3390/plants8090343

Abstract

Hybrid proline-rich proteins (HyPRPs) belong to the family of 8-cysteine motif (8CM) containing proteins that play important roles in plant development processes, and tolerance to biotic and abiotic stresses. To gain insight into the rice HyPRPs, we performed a systematic genome-wide analysis and identified 45 OsHyPRP genes encoding 46 OsHyPRP proteins. The phylogenetic relationships of OsHyPRP proteins with monocots (maize, sorghum, and Brachypodium) and a dicot (Arabidopsis) showed clustering of the majority of OsHyPRPs along with those from other monocots, which suggests lineage-specific evolution of monocots HyPRPs. Based on our previous RNA-Seq study, we selected differentially expressed OsHyPRPs genes and used quantitative real-time-PCR (qRT-PCR) to measure their transcriptional responses to biotic (Magnaporthe oryzae) and abiotic (heat, cold, and salt) stresses and hormone treatment (Abscisic acid; ABA, Methyl-Jasmonate; MeJA, and Salicylic acid; SA) in rice blast susceptible Pusa Basmati-1 (PB1) and blast-resistant near-isogenic line PB1+Pi9. The induction of OsHyPRP16 expression in response to the majority of stresses and hormonal treatments was highly correlated with the number of cis-regulatory elements present in its promoter region. In silico docking analysis of OsHyPRP16 showed its interaction with sterols of fungal/protozoan origin. The characterization of the OsHyPRP gene family enables us to recognize the plausible role of OsHyPRP16 in stress tolerance.

Highlights

IntroductionPlants are continuously exposed to biotic and abiotic stresses that adversely affect their productivity
Being sessile in nature, plants are continuously exposed to biotic and abiotic stresses that adversely affect their productivity
We identified a total of 46 putative OsHyPRPs encoded by 45 OsHyPRPs genes in rice, which showed characteristic N-terminal signal peptides followed by proline residues repeats and C-terminal conserved 8-cysteine motif (8CM) motifs

Summary

Introduction

Plants are continuously exposed to biotic and abiotic stresses that adversely affect their productivity. The plant defense response against biotic stresses can be categorized into pathogen-associated molecular patterns (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI) [1]. In both PTI and ETI, the activation of a complex network of signaling cascade pathways leads to the induction of resistance response mediated through pathogenesis-related (PR). The initiation of PR proteins against various biotic stresses has been reported in different plant species [3,4]. Plants 2019, 8, 343 usually 90–100 amino acid residues long with a conserved pattern of cysteine residues spaced as. The 8CM proteins are different from the other eight cysteine residue-containing proteins, such as lectins and agglutinin, based on the size, the pattern of cysteine spacing, an array of disulfide bonds, and hydrophobicity profile [9]

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Conclusion