A comprehensive survey of the grapevine VQ gene family and its transcriptional correlation with WRKY proteins

Abstract

WRKY proteins are a class of transcription factors (TFs) involved in the regulation of various physiological processes, including the plant response to biotic and abiotic stresses. Recent studies in Arabidopsis have revealed that some WRKY TFs interact with a class of proteins designed as VQ proteins because of their typical conserved motif (FxxxVQxLTG). So far, no information is available about the genomic organization and the function of VQ motif-containing protein in grapevine (Vitis vinifera L). In the current study, we analyzed the 12X V1 prediction of the nearly homozygous PN40024 genotype identifying up to 18 predicted VQ genes (VvVQ). VvVQs phylogenetic and bioinformatic analyses indicated that the intron-exon structures and motif distribution are highly divergent between different members of the grapevine VQ family. Moreover, the analysis of the V. vinifera cv. Corvina expression atlas revealed a tissue- and stage-specific expression of several members of the family which also showed a significant correlation with WRKY TFs. Grapevine VQ genes also exhibited altered expression in response to drought, powdery mildew infection, salicylic acid (SA) and ethylene (ETH) treatments. The present study represents the first characterization of VQ genes in a grapevine genotype and it is a pivotal foundation for further studies aimed at functionally characterizing this mostly unknown grapevine multigenic family.

Genome-Wide Identification of the VQ Protein Gene Family of Tobacco (Nicotiana tabacum L.) and Analysis of Its Expression in Response to Phytohormones and Abiotic and Biotic Stresses

“…This result is consistent with previous studies that most GmVQ genes can repond to SA treatment in soybean [17,22]. Similar cases for VQ genes under SA treatment were also reported in other species, such as Arabidopsis [11], grapevine [13], and Chinese cabbage [14]. In Arabidopsis, the expression levels of many SA-induced VQ genes peaked at early hours (e.g., 4 h post treatment) and some of them started to decline as time progressed further (e.g., 12 h or particularly 24 h post treatment) [11].…”

“…There are six variations of the conserved VQ motif among the 59 NtVQ proteins: FxxxVQxLTG (33/59), FxxxVQxFTG (10/59), FxxxVQxVTG (4/59), FxxxVQxYTG (3/59), FxxxVQxLTA (6/59), FxxxVQxLTV (2/59). In previous studies, it was known that there are six types of motifs in Arabidopsis (LTG, FTG, VTG, YTG, LTS, and LTD) [11], six types in maize (LTG, FTG, VTG, ITG, ATG, and LTA) [16], four types in rice (LTG, FTG, VTG, and ITG) [13], six types in Chinese cabbage (LTG, FTG, VTG, YTG, LTV, and LTS) [14], five types in Moso bamboo (LTG, FTG, VTG, ITG, and LTA) [18], five types in soybean (LTG, FTG, VTG, LTS, and LTR) [22], four types in apple(LTG, FTG, VTG, and LTC) [20], three types in grapevine (LTG, FTG, and VTG) [13] and seven in tomato (LTG, FTG, VTG, LTS, LTA, YTG, and HTG) [24]. Comparing the different variations of conserved VQ domain in the above plant species, we can see LTG, FTG, and VTG are the three most common ones for the VQ domain in plants.…”

“…Among the major transcriptional regulators found in plants are the VQ motif-containing proteins (designated as VQ proteins) that work independently or in combination with other TFs to regulate diverse plant growth and developmental processes and responses to biotic and abiotic stresses [10]. The VQ proteins, identified by the presence of a conserved FxxhVQxhTG amino acid motif, have been found in many plant species including both monocotyledons and dicotyledons [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. These proteins are further classified into several types based on the terminal three amino acids in the conserved motifs.…”

Genome-wide characterization, evolutionary analysis of WRKY genes in Cucurbitaceae species and assessment of its roles in resisting to powdery mildew disease

“…Previous reports showed that some rice and grape WRKY genes were co-expressed with VQ 373 genes during the response to attacks by three different pathogens [50,51] CmWRKY genes were co-expressed with 11 CmVQ transcription factors (Fig 6). Furthermore, 379 some of the co-expressed CmWRKY and CmVQ genes were shown to be response to powdery 380 mildew infection, implying that these VQ and WRKY proteins are involved in the same biological 381 pathway.…”

The CBL and CIPK Gene Family in Grapevine (Vitis vinifera): Genome-Wide Analysis and Expression Profiles in Response to Various Abiotic Stresses

“…The cis-regulatory elements were identified using PlantCARE (http://bioinformatics.psb.ugent.be/webtools/plantcare/html/) software (Wang et al, 2015). …”