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WRKY transcription factor (TF) family is well known to govern essential physiological functioning as well as regulate plant response to biotic and abiotic stress. In this study, we have identified 108 OsWRKY genes in the genome of Oryza sativa subsp. japonica, using the updated genomic data from the Rice Annotation Project Database and Oryzabase, which were further used to conduct the phylogenetic study, motif analysis, gene structure analysis, chromosomal mapping, and prediction of sub‐cellular localization. The multiple sequence alignment OsWRKY proteins revealed the presence of nine different types of alterations in the conserved heptapeptide sequence WRKYGQK associated with 19 OsWRKY genes. Physiochemical analysis discloses the hydrophobic amino acid‐rich, thermally stable, and polar nature of OsWRKY proteins. These genes were noted as highly conserved between the two cultivated sub‐species of Oryza sativa, that is Indica and japonica type. Additionally, from motif analysis, we have found a new motif, which was categorized as hAT family C‐terminal dimerization region associated with four members of group IIc. We have identified 21 stress‐responsive OsWRKY genes, and their significance to the different biotic and abiotic stress‐mediated cascades was further evaluated by analysing 1500 kb upstream sequences and this disclosed the presence of important phytohormone‐responsive cis‐elements in the OsWRKY gene, suggesting its direct involvement in defence against a wide range of external stressors and these 21 OsWRKY genes are tentatively listed as possible candidates for more study. [ABSTRACT FROM AUTHOR]

Heat shock factors (HSFs) are the key regulators of heat stress responses and play pivotal roles in tissue development and the temperature-induced regulation of secondary metabolites. In order to elucidate the roles of HSFs in Cymbidium ensifolium, we conducted a genome-wide identification of CeHSF genes and predicted their functions based on their structural features and splicing patterns. Our results revealed 22 HSF family members, with each gene containing more than one intron. According to phylogenetic analysis, 59.1% of HSFs were grouped into the A subfamily, while subfamily HSFC contained only two HSFs. And the HSF gene families were differentiated evolutionarily between plant species. Two tandem repeats were found on Chr02, and two segmental duplication pairs were observed on Chr12, Chr17, and Chr19; this provided evidence for whole-genome duplication (WGD) events in C. ensifolium. The core region of the promoter in most CeHSF genes contained cis-acting elements such as AP2/ERF and bHLH, which were associated with plant growth, development, and stress responses. Except for CeHSF11, 14, and 19, each of the remaining CeHSFs contained at least one miRNA binding site. This included binding sites for miR156, miR393, and miR319, which were responsive to temperature and other stresses. The HSF gene family exhibited significant tissue specificity in both vegetative and floral organs of C. ensifolium. CeHSF13 and CeHSF15 showed relatively significant expression in flowers compared to other genes. During flower development, CeHSF15 exhibited markedly elevated expression in the early stages of flower opening, implicating critical regulatory functions in organ development and floral scent-related regulations. During the poikilothermic treatment, CeHSF14 was upregulated over 200-fold after 6 h of heat treatment. CeHSF13 and CeHSF14 showed the highest expression at 6 h of low temperature, while the expression of CeHSF15 and CeHSF21 continuously decreased at a low temperature. The expression patterns of CeHSFs further confirmed their role in responding to temperature stress. Our study may help reveal the important roles of HSFs in plant development and metabolic regulation and show insight for the further molecular design breeding of C. ensifolium. [ABSTRACT FROM AUTHOR]

Increasing biotic and abiotic stresses are seriously impeding the growth and yield of staple crops and threatening global food security. As one of the largest classes of regulators in vascular plants, WRKY transcription factors play critical roles governing flavonoid biosynthesis during stress responses. By binding major W-box cis-elements (TGACCA/T) in target promoters, WRKYs modulate diverse signaling pathways. In this review, we optimized existing WRKY phylogenetic trees by incorporating additional plant species with WRKY proteins implicated in stress tolerance and flavonoid regulation. Based on the improved frameworks and documented results, we aim to deduce unifying themes of distinct WRKY subfamilies governing specific stress responses and flavonoid metabolism. These analyses will generate experimentally testable hypotheses regarding the putative functions of uncharacterized WRKY homologs in tuning flavonoid accumulation to enhance stress resilience. [ABSTRACT FROM AUTHOR]

The more axillary growth (MAX) gene family is a group of key genes involved in the synthesis and signal transduction of strigolactones (SLs) in plants. Although MAX genes play vital roles in plant growth and development, characterization of the MAX gene family has been limited in solanaceous crops, especially in tobacco. In this study, 74 members of the MAX family were identified in representative Solanaceae crops and classified into four groups. The physicochemical properties, gene structure, conserved protein structural domains, cis-acting elements, and expression patterns could be clearly distinguished between the biosynthetic and signal transduction subfamilies; furthermore, MAX genes in tobacco were found to be actively involved in the regulation of meristem development by responding to hormones. MAX genes involved in SL biosynthesis were more responsive to abiotic stresses than genes involved in SL signaling. Tobacco MAX genes may play an active role in stress resistance. The results of this study provide a basis for future in-depth analysis of the molecular mechanisms of MAX genes in tobacco meristem development and stress resistance. [ABSTRACT FROM AUTHOR]

Ethylene Responsive Factor (ERF) subfamily comprise the largest number of proteins in the plant AP2/ERF superfamily, and have been most extensively studied on the biological functions. Members of this subfamily have been proven to regulate plant resistances to various abiotic stresses, such as drought, salinity, chilling and some other adversities. Under these stresses, ERFs are usually activated by mitogen-activated protein kinase induced phosphorylation or escape from ubiquitin-ligase enzymes, and then form complex with nucleic proteins before binding to cis-element in promoter regions of stress responsive genes. In this review, we will discuss the phylogenetic relationships among the ERF subfamily proteins, summarize molecular mechanism how the transcriptional activity of ERFs been regulated and how ERFs of different subgroup regulate the transcription of stress responsive genes, such as high-affinity K+ transporter gene PalHKT1;2, reactive oxygen species related genes LcLTP, LcPrx, and LcRP, flavonoids synthesis related genes FtF3H and LhMYBSPLATTER, etc. Though increasing researches demonstrate that ERFs are involved in various abiotic stresses, very few interact proteins and target genes of them have been comprehensively annotated. Hence, future research prospects are described on the mechanisms of how stress signals been transited to ERFs and how ERFs regulate the transcriptional expression of stress responsive genes. [ABSTRACT FROM AUTHOR]

The Myo-Inositol-1-phosphate synthase (MIPS) gene family is involved in the myo-inositol synthesis and plays a significant role in signal transduction, membrane biogenesis, oligosaccharides synthesis, auxin storage and transport, programmed cell death and abiotic stress tolerance in plants. This study comprehensively identified the MIPS genes in Rosaceae plant species, and 51 MIPS genes were identified from 26 Rosaceae species. The phylogenetic analysis divided the MIPSs into two clades (clade I; subfamily Amygdaloideae specific, and clade II; subfamily Rosoideae specific). MIPS genes of all 26 Rosaceae species consist of similar gene structure, motif and domain composition, which shows their conserved nature. The cis-regulatory elements (CREs) analysis revealed that most Rosaceae MIPS genes play a role in growth, development, and stress responses. Furthermore, the qRT-PCR analysis also revealed the involvement of RcMIPS gene in plant development and response to abiotic stresses, including drought and heat. The results of the present study contribute to the understanding of the biological function of Rosaceae MIPS genes, and that could be used in further functional validations. [ABSTRACT FROM AUTHOR]

Background: The rubber tree (Hevea brasiliensis) is the only species capable of producing high-quality natural rubber for commercial use, and is often subjected to various abiotic stresses in non-traditional rubber plantation areas. Superoxide dismutase (SOD) is a vital metalloenzyme translated by a SOD gene family member and acts as a first-line of protection in plant cells by catalysing the disproportionation of reactive oxygen species (ROS) to produce H2O2 and O2. However, the SOD gene family is not reported in rubber trees. Methods: Here, we used hidden markov model (HMM) and BLASTP methods to identify SOD genes in the H. brasiliensis genome. Phylogenetic tree, conserved motifs, gene structures, cis elements, and gene ontology annotation (GO) analyses were performed using MEGA 6.0, MEME, TBtools, PlantCARE, and eggNOG database, respectively. HbSOD gene expression profiles were analysed using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Results: We identified nine HbSOD genes in the rubber tree genome, including five HbCSDs, two HbFSDs, and two HbMSDs. Phylogenetic relationship analysis classified the SOD proteins from the rubber tree and other related species into three subfamilies. The results of gene structure and conserved motif analysis illustrated that most HbSOD genes have similar exon-intron numbers and conserved motifs in the same evolutionary branch. Five hormone-related, four stress-related, and light-responsive elements were detected in the HbSODs' promoters. HbSODs were expressed in different tissues, gradually increased with leaf development, and were abundantly expressed in mature leaves. HbCSD2 and HbCSD4 was significantly upregulated under low and high temperatures, and salt stress, except for HbCSD2, by heat. Furthermore, most HbSOD genes were significantly upregulated by drought, except HbMSD2. These findings imply that these genes may play vital roles in rubber tree stress resistance. Our results provide a basis for further studies on the functions of HbSOD genes in rubber trees and stress response mechanisms. [ABSTRACT FROM AUTHOR]

Aspartic proteases are proteolytic enzymes widely distributed in living organisms and viruses. Although they have been extensively studied in many plant species, they are poorly described in potatoes. The present study aimed to identify and characterize S. tuberosum aspartic proteases. Gene structure, chromosome and protein domain organization, phylogeny, and subcellular predicted localization were analyzed and integrated with RNAseq data from different tissues, organs, and conditions focused on abiotic stress. Sixty-two aspartic protease genes were retrieved from the potato genome, distributed in 12 chromosomes. A high number of intronless genes and segmental and tandem duplications were detected. Phylogenetic analysis revealed eight StAP groups, named from StAPI to StAPVIII, that were differentiated into typical (StAPI), nucellin-like (StAPIIIa), and atypical aspartic proteases (StAPII, StAPIIIb to StAPVIII). RNAseq data analyses showed that gene expression was consistent with the presence of cis-acting regulatory elements on StAP promoter regions related to water deficit. The study presents the first identification and characterization of 62 aspartic protease genes and proteins on the potato genome and provides the baseline material for functional gene determinations and potato breeding programs, including gene editing mediated by CRISPR. [ABSTRACT FROM AUTHOR]

Background: The internal NAD(P)H dehydrogenase (NDA) gene family was a member of the NAD(P)H dehydrogenase (ND) gene family, mainly involved in the non-phosphorylated respiratory pathways in mitochondria and played crucial roles in response to abiotic stress. Methods: The whole genome identification, structure analysis and expression pattern of NDA gene family were conducted to analyze the NDA gene family. Results: There were 51, 52, 26, and 24 NDA genes identified in G. hirsutum, G. barbadense, G. arboreum and G. raimondii, respectively. According to the structural characteristics of genes and traits of phylogenetic tree, we divided the NDA gene family into 8 clades. Gene structure analysis showed that the NDA gene family was relatively conservative. The four Gossypium species had good collinearity, and segmental duplication played an important role in the evolution of the NDA gene family. Analysis of cis-elements showed that most GhNDA genes contained cis-elements related to light response and plant hormones (ABA, MeJA and GA). The analysis of the expression patterns of GhNDA genes under different alkaline stress showed that GhNDA genes were actively involved in the response to alkaline stress, possibly through different molecular mechanisms. By analyzing the existing RNA-Seq data after alkaline stress, it was found that an NDA family gene GhNDA32 was expressed, and then theGhNDA32 was silenced by virus-induced gene silencing (VIGS). By observing the phenotype, we found that the wilting degree of silenced plants was much higher than that of the control plant after alkaline treatment, suggesting that GhNDA32 gene was involved in the response to alkaline stress. Conclusions: In this study, GhNDAs participated in response to alkaline stress, especially NaHCO3 stress. It was of great significance for the future research on the molecular mechanism of NDA gene family in responding to abiotic stresses. [ABSTRACT FROM AUTHOR]

TCP proteins are plant-specific transcription factors that have multipurpose roles in plant developmental procedures and stress responses. Therefore, a genome-wide analysis was performed to categorize the TCP genes in the rapeseed genome. In this study, a total of 80 BnTCP genes were identified in the rapeseed genome and grouped into two main classes (PCF and CYC/TB1) according to phylogenetic analysis. The universal evolutionary analysis uncovered that BnTCP genes had experienced segmental duplications and positive selection pressure. Gene structure and conserved motif examination presented that Class I and Class II have diverse intron-exon patterns and motifs numbers. Overall, nine conserved motifs were identified and varied from 2 to 7 in all TCP genes; and some of them were gene-specific. Mainly, Class II (PCF and CYC/TB1) possessed diverse structures compared to Class I. We identified four hormone- and four stress-related responsive cis-elements in the promoter regions. Moreover, 32 bna-miRNAs from 14 families were found to be targeting 21 BnTCPs genes. Gene ontology enrichment analysis presented that the BnTCP genes were primarily related to RNA/DNA binding, metabolic processes, transcriptional regulatory activities, etc. Transcriptome-based tissue-specific expression analysis showed that only a few genes (mainly BnTCP9, BnTCP22, BnTCP25, BnTCP48, BnTCP52, BnTCP60, BnTCP66, and BnTCP74) presented higher expression in root, stem, leaf, flower, seeds, and silique among all tested tissues. Likewise, qRT-PCR-based expression analysis exhibited that BnTCP36, BnTCP39, BnTCP53, BnTCP59, and BnTCP60 showed higher expression at certain time points under various hormones and abiotic stress conditions but not by drought and MeJA. Our results opened the new groundwork for future understanding of the intricate mechanisms of BnTCP in various developmental processes and abiotic stress signaling pathways in rapeseed.

HKT subfamily II functions as Na+- K+ co-transporter and prevents plants from salinity stress. A 760 bp promoter region of AlHKT2;1 was isolated, sequenced and cloned. The full length promoter D1, has many cis -regulatory elements like MYB, MBS, W box, ABRE etc. involved in abiotic stress responses. D1 and subsequent 5′ deletions were cloned into pCAMBIA1301 and studied for its efficacy in stress conditions in heterologous system. Blue colour staining was observed in flower petals, anther lobe, and dehiscence slit of anther in T 0 plants. The T 1 seedlings showed staining in leaf veins, shoot vasculature and root except root tip. T 1 seedlings were subjected to NaCl, KCl, NaCl + KCl and ABA stresses. GUS activity was quantified by 4-methylumbelliferyl glucuronide (4-MUG) assay under control and stress conditions. The smallest deletion- D4 also showed GUS expression but highest activity was observed in D2 as compared to full length promoter and other deletions. The electrophoretic mobility shift assay using stress-induced protein with different promoter deletions revealed more prominent binding in D2. These results suggest that AlHKT2;1 promoter is involved in abiotic stress response and deletion D2 might be sufficient to drive the stress-inducible expression of various genes involved in providing stress tolerance in plants. [ABSTRACT FROM AUTHOR]

Aspartic proteases are proteolytic enzymes widely distributed in living organisms and viruses. Although they have been extensively studied in many plant species, they are poorly described in potatoes. The present study aimed to identify and characterize S. tuberosum aspartic proteases. Gene structure, chromosome and protein domain organization, phylogeny, and subcellular predicted localization were analyzed and integrated with RNAseq data from different tissues, organs, and conditions focused on abiotic stress. Sixty-two aspartic protease genes were retrieved from the potato genome, distributed in 12 chromosomes. A high number of intronless genes and segmental and tandem duplications were detected. Phylogenetic analysis revealed eight StAP groups, named from StAPI to StAPVIII, that were differentiated into typical (StAPI), nucellin-like (StAPIIIa), and atypical aspartic proteases (StAPII, StAPIIIb to StAPVIII). RNAseq data analyses showed that gene expression was consistent with the presence of cis-acting regulatory elements on StAP promoter regions related to water deficit. The study presents the first identification and characterization of 62 aspartic protease genes and proteins on the potato genome and provides the baseline material for functional gene determinations and potato breeding programs, including gene editing mediated by CRISPR.

The HVA22 gene has been isolated for the first time from the aleurone layer of barley (Hordeum vulgare). Here, we characterized the HVA22 family from citrus (C. clementina and C. sinensis). Twelve genes, 6 in each species, were identified as well as duplication events for some of them. The ORF size ranged from 235 to 804 bp and the protein molecular weight from 94 to 267 kDa. All the citrus HVA22 protein presented transmembrane location and conserved TB2/DP1/HVA22 region. Phylogenetic and gene expression analyses suggested that some citrus HVA22 play a role in flower and fruit development, and that gene expression may be regulated by hormone or environmental conditions. Other regulation levels were also predicted, such as alternative splicing and post-translational modifications. The overall data indicated that citrus HVA22 may be involved in vesicular traffic in stressed cells, and that CcHVA22d could be involved in dehydration tolerance. • This is the first citrus HVA22 family characterization. • The citrus HVA22 proteins may be associated to vesicular traffic regulation in stressed cells. • Some citrus HVA22 genes were highly expressed in reproductive organs. • Citrus HVA22 genes may be regulated by several internal and external factors. • Cc HVA22d transgenic tobacco plants showed tolerance to dehydration. [ABSTRACT FROM AUTHOR]

• Serotonin N-acetyltransferase (SNAT) genes are the key Melatonin biosynthesis genes. • BcSANT genes expression in all tissues at growth stages of flowering Chinese cabbage. • The promoter of BcSANT genes consist of hormones and abiotic stress-responsive genes cis-elements, that's play a key role in abiotic stress responses. • BcSANT genes expression pattern revelled that this gene family may involve in responding abiotic stress tolerance. Flowering Chinese cabbage (Brassica rapa ssp. Chinensis var. parachinensis) is an economically important vegetable crop that is widely cultivated in southern China and worldwide. However, plants are sensitive to environmental cues that can significantly reduce crop production. Melatonin is a pineal gland hormone that acts as a plant signalling molecule in abiotic stress tolerance. Serotonin N-acetyltransferase (SNAT) family proteins play a central role in the melatonin biosynthesis pathway and in plant responses to environmental influences. Therefore, this study aimed to identify the SNAT family genes and characterise their functions in flowering Chinese cabbage. To assess the involvement of BcSNAT family genes in abiotic stress, we performed genome-wide characterisation of the BcSNAT family, including the identification of BcSNAT genes, phylogenetic relationships, chromosomal locations, two dimensional (D), and 3D protein structures, subcellular localisation, motif analysis, cis-regulatory elements, expression profiling in different tissues, hormone treatments, and abiotic stress responses. In the flowering Chinese cabbage genome, two SNAT genes were identified (BcSNAT1 and BcSNAT2) and named according to their chromosomal locations. Phylogenetic analysis revealed that the BcSNAT genes were divided into two groups (I and II) and exhibited high homology with other plant species. Numerous cis-elements, including hormone-, stress-, metabolism-, and development-responsive cis-elements, were identified in the promoter analysis of BcSNAT genes. BcSNAT genes were expressed in different tissues of flowering Chinese cabbage and responded to melatonin, hormone treatments, and abiotic stresses. It is anticipated that BcSNAT genes may play an important role in abiotic stress tolerance by activating the melatonin signalling pathway. The results of this study may provide a theoretical foundation for further research on genetic modifications to enhance the production of protected vegetables. [ABSTRACT FROM AUTHOR]

Cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC) catalyzes a key reaction in glycolysis and encoded by a multi-gene family which showed instability expression under abiotic stress. DNA methylation is an epigenetic modification that plays an important role in gene regulation in response to abiotic stress. The comprehension of DNA methylation at promoter region of TaGAPC1 can provide insights into the transcription regulation mechanisms of plant genes under abiotic stress. In this study, we cloned TaGAPC1 genes and its promoters from two wheat genomes, then investigated the expression patterns of TaGAPC1 under osmotic and salinity stress, and analyzed the promoter sequences. Moreover, the methylation patterns of promoters under stress were confirmed. Expression analysis indicated that TaGAPC1 was induced inordinately by stresses in two wheat genotypes with contrasting drought tolerance. Several stress-related cis-acting elements (MBS, DRE, GT1 and LTR et al.) were located in its promoters. Furthermore, the osmotic and salinity stress induced the demethylation of CG and CHG nucleotide in the promoter region of Changwu134. The methylation level of CHG and CHH in promoter of Zhengyin1 was always increased under stresses, and the CG contexts remained unchanged. The cytosine loci of stress-related cis-acting elements also showed different methylation changes in this process. These results provide insights into the relationship between promoter methylation and gene expression, promoting the function investigation of GAPC. [ABSTRACT FROM AUTHOR]

Hexokinases (HXKs, EC 2.7.1.1) play important roles in metabolism, glucose (Glc) signaling, and phosphorylation of Glc and fructose and are ubiquitous in all organisms. Despite their physiological importance, the maize HXK ( ZmHXK) genes have not been analyzed systematically. We isolated and characterized nine members of the ZmHXK gene family which were distributed on 3 of the 10 maize chromosomes. A multiple sequence alignment and motif analysis revealed that the maize ZmHXK proteins share three conserved domains. Phylogenetic analysis revealed that the ZmHXK family can be divided into four subfamilies. We identified putative cis-elements in the ZmHXK promoter sequences potentially involved in phytohormone and abiotic stress responses, sugar repression, light and circadian rhythm regulation, Ca responses, seed development and germination, and CO-responsive transcriptional activation. To study the functions of maize HXK isoforms, we characterized the expression of the ZmHXK5 and ZmHXK6 genes, which are evolutionarily related to the OsHXK5 and OsHXK6 genes from rice. Analysis of tissue-specific expression patterns using quantitative real time-PCR showed that ZmHXK5 was highly expressed in tassels, while ZmHXK6 was expressed in both tassels and leaves. ZmHXK5 and ZmHXK6 expression levels were upregulated by phytohormones and by abiotic stress. [ABSTRACT FROM AUTHOR]

Highlights: [•] Identification of cis elements responsible for SamDC expression by in silico analysis. [•] qPCR analysis of SamDC expression to abiotic and biotic stress treatments. [•] Detection of SamDC regulators using identified cis-elements as probe by EMSA. [•] Southwestern Blot analysis to predict the size of the trans-acting factors. [ABSTRACT FROM AUTHOR]

X1-homologous genes (XHS) encode plant specific proteins containing three basic domains (XH, XS, zf-XS). In spite of their physiological importance, systematic analyses of ZmXHS genes have not yet been explored. In this study, we isolated and characterized ten ZmXHS genes in a whole-of-genome analysis of the maize genome. A total of ten members of this family were identified in maize genome. The ten ZmXHS genes were distributed on seven maize chromosomes. Multiple alignment and motif display results revealed that most ZmXHS proteins share all the three conserved domains. Putative cis-elements involved in abiotic stress responsive, phytohormone, pollen-specific and quantitative, seed development and germination, light and circadian rhythms regulation, Ca-responsive, root hair cell-specific, and CO-responsive transcriptional activation were observed in the promoters of ZmXHS genes. Yeast hybrid assay revealed that the XH domain of ZmXHS5 was necessary for interaction with itself and ZmXHS2. Microarray data showed that the ZmXHS genes had tissue-specific expression patterns in the maize developmental steps and biotic stresses response. Quantitative real-time PCR analysis results indicated that, except ZmXHS9, the other nine ZmXHS genes were induced in the seedling leaves by at least one of the four abiotic stresses applied. [ABSTRACT FROM AUTHOR]

Dehydrin genes encode proteins with demonstrated cryoprotective and antifreeze activity, and they respond to a variety of abiotic stress conditions that have dehydration as a common component. Two dehydrins from peach ( Prunus persica L. [Batsch.]) have been previously characterized; here, we describe the characterization of a third dehydrin from peach bark, PpDhn3, isolated by its response to low temperature. The expression of all three dehydrin genes was profiled by semi-quantitative reverse transcription PCR, and transcript initiation was mapped for all three genes using the RNA ligase-mediated 5′ rapid amplification of cDNA ends technique. PpDhn3 transcripts from bark collected in December or July, as well as transcripts from developing fruit, initiated at a single site. Although most of the PpDhn1 transcripts initiated at a similar position, those from young fruit initiated much further upstream of the consensus TATA box. Bark and fruit transcripts encoding PpDhn2 initiated ca. 30 bases downstream of a consensus TATA box; however, transcripts from ripe fruit initiated further upstream. Ripe fruit transcripts of PpDhn2 contain a 5′ leader intron which is predicted to add some 34 amino acids to the N-terminal methionine of the cognate protein when properly processed. Secondary structure prediction of sequences surrounding the TATA box suggests that conformational transitions associated with decreasing temperature contribute to the regulation of expression of the cold-responsive dehydrin genes. Taken together these results reveal new, unexpected levels of gene regulation contributing to the overall expression pattern of peach dehydrins. [ABSTRACT FROM AUTHOR]

F-box genes play an important role in the growth and development of plants, but there are few studies on its role in a plant's response to abiotic stresses. In order to further study the functions of F-box genes in tomato (Solanum lycopersicum, Sl), a total of 139 F-box genes were identified in the whole genome of tomato using bioinformatics methods, and the basic information, transcript structure, conserved motif, cis-elements, chromosomal location, gene evolution, phylogenetic relationship, expression patterns and the expression under cold stress, drought stress, jasmonic acid (JA) treatment and salicylic acid (SA) treatment were analyzed. The results showed that SlFBX genes were distributed on 12 chromosomes of tomato and were prone to TD (tandem duplication) at the ends of chromosomes. WGD (whole genome duplication), TD, PD (proximal duplication) and TRD (transposed duplication) modes seem play an important role in the expansion and evolution of tomato SlFBX genes. The most recent divergence occurred 1.3042 million years ago, between SlFBX89 and SlFBX103. The cis-elements in SlFBX genes' promoter regions were mainly responded to phytohormone and abiotic stress. Expression analysis based on transcriptome data and qRT-PCR (Real-time quantitative PCR) analysis of SlFBX genes showed that most SlFBX genes were differentially expressed under abiotic stress. SlFBX24 was significantly up-regulated at 12 h under cold stress. This study reported the SlFBX gene family of tomato for the first time, providing a theoretical basis for the detailed study of SlFBX genes in the future, especially the function of SlFBX genes under abiotic stress. [ABSTRACT FROM AUTHOR]

Background: GGPP (geranylgeranyl diphosphate) is produced in the isoprenoid pathway and mediates the function of various plant metabolites, which is synthesized by GGPPS (GGPP synthases) in plants. GGPPS characterization has not been performed in any plant species except Arabidopsis thaliana. Here, we performed a complete computational and bioinformatics analysis of GGPPS and detected their transcription expression pattern in Gossypium hirsutum for the first time so that to explore their evolutionary relationship and potential functions. Finally, we unravelled evolutionary relationship, conserved sequence logos, gene duplication and potential involvement in plant development and abiotic stresses tolerance of GGPPS genes in G. hirsutum and other plant species. Results: A total of 159 GGPPS genes from 18 plant species were identified and evolutionary analysis divided these GGPPS genes into five groups to indicate their divergence from a common ancestor. Further, GGPPS family genes were conserved during evolution and underwent segmental duplication. The identified 25 GhGGPPS genes showed diverse expression pattern particularly in ovule and fiber development indicating their vital and divers roles in the fiber development. Additionally, GhGGPPS genes exhibited wide range of responses when subjected to abiotic (heat, cold, NaCl and PEG) stresses and hormonal (BL, GA, IAA, SA and MeJA) treatments, indicating their potential roles in various biotic and abiotic stresses tolerance. Conclusions: The GGPPS genes are evolutionary conserved and might be involve in different developmental stages and stress response. Some potential key genes (e.g. GhGGPP4, GhGGPP9, and GhGGPP15) were suggested for further study and provided valuable source for cotton breeding to improve fiber quality and resistant to various stresses. [ABSTRACT FROM AUTHOR]

Histone acts as the core for nucleosomes and is a key protein component of chromatin. Among different histone variants, histone H3 (HH3) variants have been reported to play vital roles in plant development. However, biological information and evolutionary relationships of HH3 genes in cotton remain to be elucidated. The current study identified 34 HH3 genes in Gossypium hirsutum. Phylogenetic analysis classified HH3 genes of 19 plant species into eight distinct clades. Sequence logos analysis among Arabidopsis, rice, and G. hirsutum amino acid residues showed higher conservation in amino acids. Using collinearity analysis, we identified 81 orthologous/paralogous gene pairs among the four genomes (A, D, At, and Dt) of cotton. Further, orthologous/paralogous and the Ka/Ks ratio demonstrated that cotton HH3 genes experienced strong purifying selection pressure with restricted functional divergence resulting from segmental and whole genome duplication. Expression pattern analysis indicated that GhHH3 genes were preferentially expressed in cotton ovule tissues. Additionally, GhHH3 gene expression can be regulated by abiotic stresses (cold, heat, sodium chloride (NaCl), and polyethylene glycol (PEG)) and phytohormonal (brassinolide (BL), gibberellic acid (GA), indole-3-acetic acid (IAA), salicylic acid (SA), and methyl jasmonate (MeJA)) treatments, suggesting that GhHH3 genes might play roles in abiotic and hormone stress resistance. Taken together, this work provides important information to decipher complete molecular and physiological functions of HH3 genes in cotton. [ABSTRACT FROM AUTHOR]