Stress-Responsive Expression, Subcellular Localization and Protein-Protein Interactions of the Rice Metacaspase Family.

Lei Huang,Yongbo Hong,Dayong Li,Shixia Liu,Huijuan Zhang,Fengming Song

doi:10.3390/ijms160716216

Abstract

Metacaspases, a class of cysteine-dependent proteases like caspases in animals, are important regulators of programmed cell death (PCD) during development and stress responses in plants. The present study was focused on comprehensive analyses of expression patterns of the rice metacaspase (OsMC) genes in response to abiotic and biotic stresses and stress-related hormones. Results indicate that members of the OsMC family displayed differential expression patterns in response to abiotic (e.g., drought, salt, cold, and heat) and biotic (e.g., infection by Magnaporthe oryzae, Xanthomonas oryzae pv. oryzae and Rhizoctonia solani) stresses and stress-related hormones such as abscisic acid, salicylic acid, jasmonic acid, and 1-amino cyclopropane-1-carboxylic acid (a precursor of ethylene), although the responsiveness to these stresses or hormones varies to some extent. Subcellular localization analyses revealed that OsMC1 was solely localized and OsMC2 was mainly localized in the nucleus. Whereas OsMC3, OsMC4, and OsMC7 were evenly distributed in the cells, OsMC5, OsMC6, and OsMC8 were localized in cytoplasm. OsMC1 interacted with OsLSD1 and OsLSD3 while OsMC3 only interacted with OsLSD1 and that the zinc finger domain in OsMC1 is responsible for the interaction activity. The systematic expression and biochemical analyses of the OsMC family provide valuable information for further functional studies on the biological roles of OsMCs in PCD that is related to abiotic and biotic stress responses.

Highlights

Programmed cell death (PCD) is an important life process that orchestrates cell suicide and keeps the proper metabolism function [1,2]
Expression Patterns of OsMCs in Response to Abiotic Stresses. Abiotic stresses such as dehydration and extreme temperature are the main deleterious factors affecting on plant growth/development and crop yield [39]
We found that infection with M. oryzae, Xanthomonas oryzae pv. oryzae (Xoo), or R. solani, thee different pathogens with distinct infection styles, did cause transcriptional reprogramming in expression of the OsMC genes

Summary

Introduction

Programmed cell death (PCD) is an important life process that orchestrates cell suicide and keeps the proper metabolism function [1,2]. During PCD, a kind of enzymes, known as caspases, are often activated and initiate the cell death program [3,4,5,6]. Caspases are a family of cysteine-dependent aspartate-directed proteases, which cleave a variety of intracellular polypeptides and cause the stereotypic morphological and biochemical changes of the cells [7]. Higher plants do not have close homologues of caspases, but possess a phylogenetically distant family of caspase-like proteins, called metacaspases [8]. Recent genome-wide characterizations in various plant species have revealed that the plant metacaspases are presented as a multigene family. There are nine members in Arabidopsis [9], 8 or 9 members in rice [10,11] and 6 members in grapevine [12]

Methods

Results

Discussion

Conclusion