Identification, characterization and expression analysis of the VQ motif-containing gene family in tea plant (Camellia sinensis)

Abstract

BackgroundVQ motif-containing (VQ) proteins are plant-specific proteins that interact with WRKY transcription factors and play important roles in plant growth, development and stress response. To date, VQ gene families have been identified and characterized in many plant species, including Arabidopsis, rice and grapevine. However, the VQ gene family in tea plant has not been reported, and the biological functions of this family remain unknown.ResultsIn total, 25 CsVQ genes were identified based on the genome and transcriptome of tea plant, and a comprehensive bioinformatics analysis was performed. The CsVQ proteins all contained the typical conserved motif FxxhVQxhTG, and most proteins were localized in the nucleus. The phylogenetic analysis showed that the VQ proteins were classified into 5 groups (I, III-VI); the evolution of the CsVQ proteins is consistent with the evolutionary process of plants, and close proteins shared similar structures and functions. In addition, the expression analysis revealed that the CsVQ genes play important roles in the process of tea plant growth, development and response to salt and drought stress. Furthermore, a potential regulatory network including the interactions of CsVQ proteins with CsWRKY transcription factors and the regulation of upstream microRNA that is closely related to the above-mentioned processes is proposed.ConclusionsThe results of this study increase our understanding and characterization of CsVQ genes and their encoded proteins in tea plant. This systematic analysis provided comprehensive information for further studies investigating the biological functions of CsVQ proteins in various developmental processes of tea plants.Electronic supplementary materialThe online version of this article (10.1186/s12864-018-5107-x) contains supplementary material, which is available to authorized users.

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

“…On the contrary, four genes (NtVQ11, NtVQ12, NtVQ20, and NtVQ23) encode protein of more than or equal to 400 amino acids. Furthermore, in silico prediction of the subcellular localization of the encoded NtVQ proteins showed that the majority localize to the nucleus ( Supplementary Table S3), which is similar to many known plants, such as Arabidopsis [11] and tea [23]. Thus, this VQ family appears to be a relatively conserved family evolutionarily.…”

“…Analysis of the phylogenic tree of tobacco VQ proteins has shown that the clades are similar to those described for Arabidopsis [11] and tomato [24]. Tobacco NtVQ protein has an average of 223.5 amino acids, which is similar to the known VQ protein in many plants, where most of the VQ genes encode fewer than 300 amino acids, including Arabidopsis [11], rice [12], maize [16], Moso bamboo [18], apple [20], poplar [15], Chinese Cabbage [14], soybean [22], tomato [24], tea [23], and so on. On the contrary, four genes (NtVQ11, NtVQ12, NtVQ20, and NtVQ23) encode protein of more than or equal to 400 amino acids.…”

“…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.…”

Motif analysis in co-expression networks reveals regulatory elements in plants: The peach as a model

“…This can be explained by the fact that some promoter sequences may encompass multiple TFBSs of perhaps interacting TFs. Indeed, TFs have been reported to frequently operate in combination (Guo et al, 2018; Kumar et al, 2018). Combinatorial regulation is required to confer specific responses in a particular tissue and under a particular stress.…”

Integrated Analysis of Long Non-coding RNAs (lncRNAs) and mRNAs Reveals the Regulatory Role of lncRNAs Associated With Salt Resistance in Camellia sinensis

“…In our previous report, we performed an Illumina RNA sequencing (RNA-Seq) to compare the transcriptomes of tea plants treated with and without NaCl, and many differentially expressed mRNAs involved in signal transduction pathways, transcription factors (TFs), and other functional genes under salt stress were identified (Wan et al, 2018). Previous reports have also shown that many mRNAs and proteins in tea plants, such as CsSnRK2 (Zhang et al, 2018), CsAQP (Yue et al, 2014), and CsVQ (Guo et al, 2018), respond to salt stress. Long non-coding RNAs (lncRNAs) are important regulatory factors that respond to various abiotic stresses in plants; however, their functions in responding to salt stress have not been studied in tea plants.…”