Isolation and molecular characterization of ERF1, an ethylene response factor gene from durum wheat (Triticum turgidum L. subsp. durum), potentially involved in salt-stress responses

Abstract

As food crop, wheat is of prime importance for human society. Nevertheless, our understanding of the genetic and molecular mechanisms controlling wheat productivity conditions has been, so far, hampered by the lack of sufficient genomic resources. The present work describes the isolation and characterization of TdERF1, an ERF gene from durum wheat (Triticum turgidum L. subsp. durum). The structural features of TdERF1 supported the hypothesis that it is a novel member of the ERF family in durum wheat and, considering its close similarity to TaERF1 of Triticum aestivum, it probably plays a similar role in mediating responses to environmental stresses. TdERF1 displayed an expression pattern that discriminated between two durum wheat genotypes contrasted with regard to salt-stress tolerance. The high number of cis-regulatory elements related to stress responses present in the TdERF1 promoter and the ability of TdERF1 to regulate the transcription of ethylene and drought-responsive promoters clearly indicated its potential role in mediating plant responses to a wide variety of environmental constrains. TdERF1 was also regulated by abscisic acid, ethylene, auxin, and salicylic acid, suggesting that it may be at the crossroads of multiple hormone signalling pathways. Four TdERF1 allelic variants have been identified in durum wheat genome, all shown to be transcriptionally active. Interestingly, the expression of one allelic form is specific to the tolerant genotype, further supporting the hypothesis that this gene is probably associated with the susceptibility/tolerance mechanism to salt stress. In this regard, the TdERF1 gene may provide a discriminating marker between tolerant and sensitive wheat varieties.

TdERF1, an ethylene response factor associated with dehydration responses in durum wheat (Triticum turgidum L. subsp. durum)

“…The expression pattern of TdERF1 was also been shown to be discriminating between the 2 wheat varieties contrasted in terms of salt-stress tolerance. 13 Using physiological criteria, the data presented here confirm that GR and OR durum wheat genotypes display contrasted behavior with regards to salt stress. The data also show that TdERF1 expression induced under water stress supporting a potential role of this ERF gene in responses to both salt and dehydration stress.…”

“…though genes belonging to AP2/ERF family are known to be involved in many stress responses, [10][11][12] so far, they have not been investigated in durum wheat. In fact, a unique ERF transcription factor named TdERF1 was recently isolated and its expression has been shown to be associated with salt stress 13 . Two genotypes of T. durum, named GR (Grecale) and OR (Om Rabiia), were assessed for their saltstress tolerance using germination capacity and stomatal conductance tests indicating that GR and OR are salt tolerant and sensitive, respectively.…”

“…The expression of TdERF1 in response to dehydration was assessed at the transcript level in OR and GR genotypes of durum wheat using specific primers nondiscriminating between the allelic forms of TdERF1. 13 in a quantitative real-time PCR. The data indicate that after 4h of water stress (Fig.…”

RNAseq analysis reveals pathways and candidate genes associated with salinity tolerance in a spaceflight-induced wheat mutant

“…Makhlouf et al . reported that an ethylene response factor gene is probably associated with salt tolerance in wheat 61 ; ethylene also plays roles in salt responses in plants 59, 62, 63 . Five genes involved in ethylene biosynthesis or regulation, were up-regulated in the S_ st1 vs st1 and the S_ st1 vs S_WT comparisons (Table 2), and these expression patterns were confirmed by qPCR (Fig.…”

Isolation and molecular characterization of a novel WIN1/SHN1 ethylene-responsive transcription factor TdSHN1 from durum wheat (Triticum turgidum. L. subsp. durum)

“…In contrast to rice and bread wheat, studies on durum wheat AP2/ERF genes are scarce. For instance, only one gene encoding an ERF1 protein has been isolated from durum wheat (Makhloufi et al 2014).…”