Characterization of the Esi3/RCI2/PMP3 gene family in the Triticeae

Sabrina C Brunetti,Patrick J Gulick,Michelle K M Arseneault

doi:10.1186/s12864-018-5311-8

Abstract

BackgroundMembers of the Early Salt Induced 3 (Esi3/RCI2/PMP3) gene family in plants have been shown to be induced in response to both biotic and abiotic stresses and to enhance stress tolerance in both transgenic plants and Saccharomyces cerevisiae. Esi3 was first identified as a salt stress induced gene in the salt tolerant wild wheat grass, Lophopyrum elongatum, and subsequently homologous genes in many other species were found to be members of the gene family. These include Arabidopsis thaliana and Oryza sativa where they are referred to as Rare Cold Inducible 2 (RCI2), and Zea mays where they are referred to as Plasma Membrane Protein 3 (PMP3). This study characterizes the Esi3 family members in Triticum aestivum and explores the tissue specific expression patterns of the gene family members as well as their response to a variety of environmental stresses.ResultsThe Esi3 gene family was found to have a total of 29 family members comprised of ten paralogous groups in the hexaploid T. aestivum. Each paralogous group contains three homeologous copies, one in each of the A, B and D genomes with the exception of Esi3–2 which is missing the B copy. The genes of the Esi3 gene family were also identified in four other monocot species, Aegilops tauschii, Hordeum vulgare, Secale cereale and Sorghum bicolor, and were confirmed or corrected for Brachypodium distachyon, Oryza sativa and Zea mays, as well as the dicot Arabidopsis thaliana. Gene expression of the Esi3s was analyzed using tissue-specific, abiotic and biotic stress RNA-Seq 454 sequence libraries and Affymetrix microarray data for T. aestivum.ConclusionsMembers of nearly all paralogous groups of the Esi3 genes in T. aestivum have altered gene expression in response to abiotic or biotic stress conditions. In addition, there are modest differences in gene expression among homeologous members of the gene family. This suggests that the Esi3 gene family plays an important role in the plants response to the stresses presented in this study. The Esi3–9 in T. aestivum has a unique N terminal extension placing it into Group III, a new group for the Esi3/RCI2/PMP3 gene family.

Highlights

Members of the Early Salt Induced 3 (Esi3/Rare Cold Inducible 2 (RCI2)/Plasma Membrane Protein 3 (PMP3)) gene family in plants have been shown to be induced in response to both biotic and abiotic stresses and to enhance stress tolerance in both transgenic plants and Saccharomyces cerevisiae
Early Salt-Induced 3 (Esi3) genes in Triticum aestivum Twenty-nine Esi3/RCI2/PMP3 genes were found in the hexaploid genome of T. aestivum
The sequences of the gene family members were confirmed in three independent sequence databases, the International Wheat Genome Sequencing Consortium (IWGSC) database of genomic chromosomal survey sequences [22], and the transcriptome shotgun assembly (TSA) and expressed sequence tag (EST) databases for T. aestivum at the National Center for Biological Information (NCBI)

Summary

Introduction

Members of the Early Salt Induced 3 (Esi3/RCI2/PMP3) gene family in plants have been shown to be induced in response to both biotic and abiotic stresses and to enhance stress tolerance in both transgenic plants and Saccharomyces cerevisiae. Esi was first identified as a salt stress induced gene in the salt tolerant wild wheat grass, Lophopyrum elongatum, and subsequently homologous genes in many other species were found to be members of the gene family. These include Arabidopsis thaliana and Oryza sativa where they are referred to as Rare Cold Inducible 2 (RCI2), and Zea mays where they are referred to as Plasma Membrane Protein 3 (PMP3). The Δpmp mutation in S. cerevisiae can be complemented by many but not all members of the gene families from other plant species including Zea mays [10], Medicago truncatula [11], Oryza sativa [8] and the alkali grass, Puccinellia tenuiflora [12]

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Conclusion