Genome-wide identification of the DUF668 gene family in cotton and expression profiling analysis of GhDUF668 in Gossypium hirsutum under adverse stress

Genome-wide analysis and prediction of chloroplast and mitochondrial RNA editing sites of AGC gene family in cotton (Gossypium hirsutum L.) for abiotic stress tolerance

BACKGROUND

Cotton is one of the topmost fiber crops throughout the globe. During the last decade, abrupt changes in the climate resulted in drought, heat, and salinity. These stresses have seriously affected cotton production and significant losses all over the textile industry. The GhAGC kinase, a subfamily of AGC group and member of serine/threonine (Ser/Thr) protein kinases group and is highly conserved among eukaryotic organisms. The AGC kinases are compulsory elements of cell development, metabolic processes, and cell death in mammalian systems. The investigation of RNA editing sites within the organelle genomes of multicellular vascular plants, such as Gossypium hirsutum holds significant importance in understanding the regulation of gene expression at the post-transcriptional level.

METHODS

In present work, we characterized twenty-eight GhAGC genes in cotton and constructed phylogenetic tree using nine different species from the most primitive to the most recent.

RESULTS

In sequence logos analyses, highly conserved amino acid residues were found in G. hirsutum, G. arboretum, G. raimondii and A. thaliana. The occurrence of cis-acting growth and stress-related elements in the promoter regions of GhAGCs highlight the significance of these factors in plant development and abiotic stress tolerance. Ka/Ks levels demonstrated that purifying selection pressure resulting from segmental events was applied to GhAGC with little functional divergence. We focused on identifying RNA editing sites in G. hirsutum organelles, specifically in the chloroplast and mitochondria, across all 28 AGC genes.

CONCLUSION

The positive role of GhAGCs was explored by quantifying the expression in the plant tissues under abiotic stress. These findings help in understanding the role of GhAGC genes under abiotic stresses which may further be used in cotton breeding for the development of climate smart varieties in abruptly changing climate.

The functions of laccase gene GhLAC15 in fiber colouration and development in brown-colored cotton

The monotonicity of color type in naturally colored cottons (NCCs) has become the main limiting factor to their widespread use, simultaneously coexisting with poor fiber quality. The synchronous improvement of fiber quality and color become more urgent and crucial as the demand for sustainable development increases. The homologous gene of wild cotton Gossypium stocksii LAC15 in G. hirsutum, GhLAC15, was also dominantly expressed in the developing fibers of brown cotton XC20 from 5 DPA (day post anthesis) to 25 DPA, especially at the secondary cell wall thickening stage (20 DPA and 25 DPA). In XC20 plants with downregulated GhLAC15 (GhLAC15i), a remarkable reduction in proanthocyanidins (PAs) and lignin contents was observed. Some of the key genes in the phenylpropane and flavonoid biosynthesis pathway were down-regulated in GhLAC15i plants. Notably, the fiber length of GhLAC15i plants showed an obvious increase and the fiber color was lightened. Moreover, we found that the thickness of cotton fiber cell wall was decreased in GhLAC15i plants and the fiber surface became smoother compared to that of WT. Taken together, this study revealed that GhLAC15 played an important role in PAs and lignin biosynthesis in naturally colored cotton fibers. It might mediate fiber color and fiber quality by catalyzing PAs oxidation and lignin polymerization, ultimately regulating fiber colouration and development.

Genome-wide identification, characterization and expression analysis of the DUF668 gene family in tomato

The domain of unknown function 668 (DUF668) is a gene family that may play a key role in plant growth and development as well as in responding to adversity coercion stresses. However, the DUF668 gene family has not yet been well identified and characterized in tomato. In this study, a total of nine putative SlDUF668 genes were identified in tomato, distributed on six chromosomes. Phylogenetic analyses revealed that SlDUF668 proteins were classified into two major groups. Members within the same group largely displayed analogous gene structure and conserved motif compositions. Several cis-elements were exhibited in the upstream sequences of the SlDUF668 genes, including elements implicated in plant growth and development processes, abiotic stress and hormone responses. Further, the study assessed the expression patterns of the SlDUF668 gene family in various tomato tissues, five plant hormones treatments, three abiotic stresses using qRT-PCR. The SlDUF668 genes expressed ubiquitously in various tissues, and five genes (SlDUF668-04, SlDUF668-06, SlDUF668-07, SlDUF668-08 and SlDUF668-09) showed tissue specificity. And SlDUF668 genes responded to abiotic stresses such as salt, drought and cold to varying degrees. Overall, our study provided a base for the tomato DUF668 gene family and laid a foundation for further understanding the functional characteristics of DUF668 genes in tomato plants.

Transcriptome analysis of Gossypium hirsutum cultivar Zhongzhimian No.2 uncovers the gene regulatory networks involved in defense against Verticillium dahliae

BACKGROUND

Cotton is globally important crop. Verticillium wilt (VW), caused by Verticillium dahliae, is the most destructive disease in cotton, reducing yield and fiber quality by over 50% of cotton acreage. Breeding resistant cotton cultivars has proven to be an efficient strategy for improving the resistance of cotton to V. dahliae. However, the lack of understanding of the genetic basis of VW resistance may hinder the progress in deploying elite cultivars with proven resistance.

RESULTS

We planted the VW-resistant Gossypium hirsutum cultivar Zhongzhimian No.2 (ZZM2) in an artificial greenhouse and disease nursery. ZZM2 cotton was subsequently subjected to transcriptome sequencing after Vd991 inoculation (6, 12, 24, 48, and 72 h post-inoculation). Several differentially expressed genes (DEGs) were identified in response to V. dahliae infection, mainly involved in resistance processes, such as flavonoid and terpenoid quinone biosynthesis, plant hormone signaling, MAPK signaling, phenylpropanoid biosynthesis, and pyruvate metabolism. Compared to the susceptible cultivar Junmian No.1 (J1), oxidoreductase activity and reactive oxygen species (ROS) production were significantly increased in ZZM2. Furthermore, gene silencing of cytochrome c oxidase subunit 1 (COX1), which is involved in the oxidation-reduction process in ZZM2, compromised its resistance to V. dahliae, suggesting that COX1 contributes to VW resistance in ZZM2.

CONCLUSIONS

Our data demonstrate that the G. hirsutum cultivar ZZM2 responds to V. dahliae inoculation through resistance-related processes, especially the oxidation-reduction process. This enhances our understanding of the mechanisms regulating the ZZM2 defense against VW.

Genome-Wide Analysis of VILLIN Gene Family Associated with Stress Responses in Cotton (Gossypium spp.)

The VILLIN (VLN) protein plays a crucial role in regulating the actin cytoskeleton, which is involved in numerous developmental processes, and is crucial for plant responses to both biotic and abiotic factors. Although various plants have been studied to understand the VLN gene family and its potential functions, there has been limited exploration of VLN genes in Gossypium and fiber crops. In the present study, we characterized 94 VLNs from Gossypium species and 101 VLNs from related higher plants such as Oryza sativa and Zea mays and some fungal, algal, and animal species. By combining these VLN sequences with other Gossypium spp., we classified the VLN gene family into three distinct groups, based on their phylogenetic relationships. A more in-depth examination of Gossypium hirsutum VLNs revealed that 14 GhVLNs were distributed across 12 of the 26 chromosomes. These genes exhibit specific structures and protein motifs corresponding to their respective groups. GhVLN promoters are enriched with cis-elements related to abiotic stress responses, hormonal signals, and developmental processes. Notably, a significant number of cis-elements were associated with the light responses. Additionally, our analysis of gene-expression patterns indicated that most GhVLNs were expressed in various tissues, with certain members exhibiting particularly high expression levels in sepals, stems, and tori, as well as in stress responses. The present study potentially provides fundamental insights into the VLN gene family and could serve as a valuable reference for further elucidating the diverse functions of VLN genes in cotton.

Genome-Wide Identification of DUF668 Gene Family and Expression Analysis under F. solani, Chilling, and Waterlogging Stresses in Zingiber officinale

The domains of unknown function (DUF) superfamilies contain proteins with conserved amino acid sequences without known functions. Among them, DUF668 was indicated widely involving the stress response of plants. However, understanding ZoDUF668 is still lacking. Here, 12 ZoDUF668 genes were identified in ginger by the bioinformatics method and unevenly distributed on six chromosomes. Conserved domain analysis showed that members of the same subfamily had similar conserved motifs and gene structures. The promoter region of ZoDUF668s contained the light, plant hormone and stress-responsive elements. The prediction of miRNA targeting relationship showed that nine ginger miRNAs targeted four ZoDUF668 genes through cleavage. The expression patterns of 12 ZoDUF668 genes under biotic and abiotic stress were analyzed using RT-qPCR. The results showed that the expression of seven ZoDUF668 genes was significantly downregulated under Fusarium solani infection, six ZoDUF668 genes were upregulated under cold stress, and five ZoDUF668 genes were upregulated under waterlogging stress. These results indicate that the ZoDUF668 gene has different expression patterns under different stress conditions. This study provides excellent candidate genes and provides a reference for stress-resistance research in ginger.

Glyceraldehyde-3-phosphate dehydrogenase Gh_GAPDH9 is associated with drought resistance in Gossypium hirsutum

Background

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is the central enzyme of glycolysis and plays important regulatory roles in plant growth and development and responses to adverse stress conditions. However, studies on the characteristics and functions of cotton GAPDH family genes are still lacking.

Methods

In this study, genome-wide identification of the cotton GAPDH gene family was performed, and the phylogeny, gene structures, promoter progenitors and expression profiles of upland cotton GAPDH gene family members were explored by bioinformatics analysis to highlight potential functions. The functions of GhGAPDH9 in response to drought stress were initially validated based on RNA-seq, qRT‒PCR, VIGS techniques and overexpression laying a foundation for further studies on the functions of GAPDH genes.

Results

This study is the first systematic analysis of the cotton GAPDH gene family, which contains a total of 84 GAPDH genes, among which upland cotton contains 27 members. Quantitative, phylogenetic and covariance analyses of the genes revealed that the GAPDH gene family has been conserved during the evolution of cotton. Promoter analysis revealed that most cis-acting elements were related to MeJA and ABA. Based on the identified promoter cis-acting elements and RNA-seq data, it was hypothesized that Gh_GAPDH9, Gh_GAPDH11, Gh_GAPDH19 and Gh_GAPDH21 are involved in the response of cotton to abiotic stress. The expression levels of the Gh_GAPDH9 gene in two drought-resistant and two drought-sensitive materials were analyzed by qRT‒PCR and found to be high early in the treatment period in the drought-resistant material. The silencing of Gh_GAPDH9 based on virus-induced gene silencing (VIGS) technology resulted in significant leaf wilting or whole-plant dieback in silenced plants after drought stress compared to the control. The content of-malondialdehyde (MDA) in cotton leaves was significantly increased, and the content of proline (Pro) and chlorophyll (Chl) was reduced. In addition, the leaf wilting and dryness of transgenic lines under drought stress were lower than those of wild-type Arabidopsis, indicating that Gh_GAPDH9 is a positive regulator of drought resistance. In conclusion, our results demonstrate that GAPDH genes play an important role in the response of cotton to abiotic stresses and provide preliminary validation of the function of the Gh_GAPDH9 gene under drought stress. These findings provide an important theoretical basis for further studies on the function of the Gh_GAPDH9 gene and the molecular mechanism of the drought response in cotton.

Genome-Wide Analysis and Expression Profiling of DUF668 Genes in Glycine max under Salt Stress

The DUF668 gene performs a critical role in mitigating the impact of abiotic stress factors. In this study, we identified 30 DUF668 genes in a soybean genome, distributed across fifteen chromosomes. The phylogenetic analysis classified the DUF668 genes into three groups (group I, group II, and group III). Interestingly, gene structure analysis illustrated that several GmDUF668 genes were without introns. Furthermore, the subcellular localization results suggested that GmDUF668 proteins were present in the nucleus, mitochondria, cytoplasm, and plasma membrane. GmDUF668 promoters were analyzed in silico to gain insight into the presence of regulatory sequences for TFs binding. The expression profiling illustrated that GmDUF668 genes showed expression in leaves, roots, nodules, and flowers. To investigate their response to salt stress, we utilized the RNA sequencing data of GmDUF668 genes. The results unveiled that GmDUF668-8, GmDUF668-20, and GmDUF668-30 genes were upregulated against salt stress treatment. We further validated these findings using qRT-PCR analysis. These findings provide a scientific basis to explore the functions of GmDUF668 genes against different stress conditions.

Genome-wide identification and analysis of a cotton secretome reveals its role in resistance against Verticillium dahliae

BACKGROUND

The extracellular space between the cell wall and plasma membrane is a battlefield in plant-pathogen interactions. Within this space, the pathogen employs its secretome to attack the host in a variety of ways, including immunity manipulation. However, the role of the plant secretome is rarely studied for its role in disease resistance.

RESULTS

Here, we examined the secretome of Verticillium wilt-resistant Gossypium hirsutum cultivar Zhongzhimian No.2 (ZZM2, encoding 95,327 predicted coding sequences) to determine its role in disease resistance against the wilt causal agent, Verticillium dahliae. Bioinformatics-driven analyses showed that the ZZM2 genome encodes 2085 secreted proteins and that these display disequilibrium in their distribution among the chromosomes. The cotton secretome displayed differences in the abundance of certain amino acid residues as compared to the remaining encoded proteins due to the localization of these putative proteins in the extracellular space. The secretome analysis revealed conservation for an allotetraploid genome, which nevertheless exhibited variation among orthologs and comparable unique genes between the two sub-genomes. Secretome annotation strongly suggested its involvement in extracellular stress responses (hydrolase activity, oxidoreductase activity, and extracellular region, etc.), thus contributing to resistance against the V. dahliae infection. Furthermore, the defense response genes (immunity marker NbHIN1, salicylic acid marker NbPR1, and jasmonic acid marker NbLOX4) were activated to varying degrees when Nicotina benthamiana leaves were agro-infiltrated with 28 randomly selected members, suggesting that the secretome plays an important role in the immunity response. Finally, gene silencing assays of 11 members from 13 selected candidates in ZZM2 displayed higher susceptibility to V. dahliae, suggesting that the secretome members confer the Verticillium wilt resistance in cotton.

CONCLUSIONS

Our data demonstrate that the cotton secretome plays an important role in Verticillium wilt resistance, facilitating the development of the resistance gene markers and increasing the understanding of the mechanisms regulating disease resistance.

Cloning and functional analysis of GhDFR1, a key gene of flavonoid synthesis pathway in naturally colored cotton

BACKGROUND

The naturally colored brown cotton fiber is the most widely used environmentally friendly textile material, which primarily contains proanthocyanidins and their derivatives. Many structural genes in the flavonoid synthesis pathway are known to improve the genetic resources of naturally colored cotton. Among them, DFR is a crucial late enzyme to synthesis both anthocyanins and proanthocyanidins in the plant flavonoid pathway.

METHODS

The protein sequences of GhDFRs were analyzed using bioinformatic tools. The expression levels of GhDFRs in various tissues and organs of upland cotton Zongxu1 (ZX1), were analyzed by quantitative real-time PCR, and the expression pattern of GhDFR1 during fiber development of white cotton and brown cotton was analyzed further. The function of GhDFR1 in NCC ZX1 was preliminarily analyzed by virus induced gene silencing (VIGS) technology.

RESULTS

Bioinformatic analysis revealed that GhDFRs sequences in upland cotton genome were extremely conserved. Furthermore, evolutionary tree analysis revealed that the functions of GhDFR1 and GhDFR2, and GhDFR3 and GhDFR4, presented different and shared some similarities. Our study showed GhDFR1 and GhDFR2 were specifically expressed in fibers, while GhDFR3 and GhDFR4 were specifically expressed in petals. GhDFR1 was exclusively expressed in brown cotton fiber at various stages of development and progressively increased with the growth of fiber, but the trend of expression in white cotton was quite the opposite. We silenced GhDFR1 expression in brown cotton fiber using VIGS technology, and observed the VIGS-interference plants. After reducing the expression level of GhDFR1, the period for significant GhDFR1 expression in the developing fibers changed, reducing the content of anthocyanins, and lightening the color of mature cotton fibers.

CONCLUSION

GhDFR1 was preferentially expressed in brown cotton during fiber development. The timing of GhDFR1 expression for flavonoid synthesis altered, resulting in anthocyanin contents reduced and the fiber color of the GhDFR1i lines lightened. These findings showed the role of GhDFR1 in fiber coloration of NCC and provided a new candidate for NCC genetic improvement.

Quantitative trait locus mapping and identification of candidate genes for resistance to Verticillium wilt in four recombinant inbred line populations of Gossypium hirsutum

Improving resistance to Verticillium wilt is of great significance for achieving high and stable yields of Upland cotton (Gossypium hirsutum). To deeply understand the genetic basis of cotton resistance to Verticillium wilt, Verticillium wilt-resistant Upland Lumianyan 28 and four Verticillium wilt-susceptible Acala cotton cultivars were used to create four recombinant inbred line (RIL) populations of 469 families through nested hybridization. Phenotypic data collected in five stressful environments were used to select resistant and sensitive lines and create a mixed pool of extreme phenotypes for BSA-seq. A total of 8 QTLs associated with Verticillium wilt resistance were identified on 4 chromosomes, of which qVW-A12-5 was detected simultaneously in the RIL populations and in one of the RIL populations and was identified for the first time. According to the sequence comparison and transcriptome analysis of candidate genes in the QTL interval between parents and pools, 4 genes were identified in the qVW-A12-5 interval. qRT-PCR of parental and phenotypically extreme lines revealed that Gh_CPR30 was induced by and may be a candidate gene for resistance to Verticillium wilt in G. hirsutum. Furthermore, VIGS technology revealed that the disease severity index (DSI) of the Gh_CPR30-silenced plants was significantly higher than that of the control. These results indicate that the Gh_CPR30 gene plays an important role in the resistance of G. hirsutum to Verticillium wilt, and the study provides a molecular basis for analyzing the molecular mechanism underlying G. hirsutum resistance to Verticillium wilt.

Genome-wide identification and expression reveal the involvement of the FCS-like zinc finger (FLZ) gene family in Gossypium hirsutum at low temperature

FCS-like zinc finger (FLZ) is a plant-specific gene family that plays an important regulatory role in plant growth and development and its response to stress. However, studies on the characteristics and functions of cotton FLZ family genes are still lacking. This study systematically identified members of the cotton FLZ gene family based on cotton genome data. The cotton FLZ family genes were systematically analyzed by bioinformatics, and their expression patterns in different tissues and under low-temperature stress were analyzed by transcriptome and qRT-PCR. The G. hirsutum genome contains 56 FLZ genes distributed on 20 chromosomes, and most of them are located in the nucleus. According to the number and evolution analysis of FLZ family genes, FLZ family genes can be divided into five subgroups in cotton. The G. hirsutum FLZ gene has a wide range of tissue expression types, among which the expression is generally higher in roots, stems, leaves, receptacles and calyx. Through promoter analysis, it was found that it contained the most cis-acting elements related to methyl jasmonate (MeJA) and abscisic acid (ABA). Combined with the promoter and qRT-PCR results, it was speculated that GhFLZ11, GhFLZ25, GhFLZ44 and GhFLZ55 were involved in the response of cotton to low-temperature stress. Taken together, our findings suggest an important role for the FLZ gene family in the cotton response to cold stress. This study provides an important theoretical basis for further research on the function of the FLZ gene family and the molecular mechanism of the cotton response to low temperature.

Genome-Wide Identification of DUF668 Gene Family and Expression Analysis under Drought and Salt Stresses in Sweet Potato [Ipomoea batatas (L.) Lam]

The domain of unknown function 668 (DUF668) is a gene family that plays a vital role in responses to adversity coercion stresses in plant. However, the function of the DUF668 gene family is not fully understood in sweet potato. In this study, bioinformatics methods were used to analyze the number, physicochemical properties, evolution, structure, and promoter cis-acting elements of the IbDUF668 family genes, and RNA-seq and qRT-PCR were performed to detect gene expression and their regulation under hormonal and abiotic stress. A total of 14 IbDUF668 proteins were identified in sweet potato, distributed on nine chromosomes. By phylogenetic analysis, IbDUF668 proteins can be divided into two subfamilies. Transcriptome expression profiling revealed that many genes from DUF668 in sweet potato showed specificity and differential expression under cold, heat, drought, salt and hormones (ABA, GA3 and IAA). Four genes (IbDUF668-6, 7, 11 and 13) of sweet potato were significantly upregulated by qRT-PCR under ABA, drought and NaCl stress. Results suggest that the DUF668 gene family is involved in drought and salt tolerance in sweet potato, and it will further provide the basic information of DUF668 gene mechanisms in plants.

Genome Resource for the Verticillium Wilt Resistant Gossypium hirsutum Cultivar Zhongzhimian No. 2

Verticillium wilt, caused by the fungal pathogen Verticillium dahliae, is the major cause of disease-related yield losses in cotton (Gossypium hirsutum). Despite these losses, the major cultivars of G. hirsutum remain highly susceptible to Verticillium wilt. The lack of understanding on the genetic basis for Verticillium wilt resistance may further hinder progress in deploying elite cultivars with proven resistance, such as the wilt resistant G. hirsutum cultivar Zhongzhimian No. 2. To help remedy this knowledge gap, we sequenced the whole genome of Zhongzhimian No. 2 and assembled it from a combination of PacBio long reads, Illumina short reads, and high-throughput chromosome conformation capture technologies. The final assembly of the genome was 2.33 Gb, encoding 95,327 predicted coding sequences. The GC content was 34.39% with 99.2% of the bases anchored to 26 pseudo-chromosomes that ranged from 53.8 to 127.7 Mb. This resource will help gain a detailed understanding of the genomic features governing high yield and Verticillium wilt resistance in this cultivar. Comparative genomics will be particularly helpful, since there are several published genomes of other Gossypium species. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Genome-wide identification and expression analysis of the bHLH gene family in cauliflower (Brassica oleracea L.)

Basic helix-loop-helix (bHLH) transcription factors (TFs) are one of the largest TF families in plant species, and they play important roles in plant growth, development and stress responses. The present study systematically identified members of the cauliflower (Brassica oleracea L.) bHLH gene family based on genomic data. Analysis of bHLH family gene numbers, evolution, collinearity, gene structures and motifs indicated that cauliflower contained 256 bHLH family genes distributed on 10 chromosomes. Most of these genes have been localized in the nucleus, and they were divided into 18 subgroups which have been relatively conserved during evolution. Promoter analysis showed that most cis-acting elements were related to MeJA and ABA. Expression analysis suggested that 14 bHLH genes may be involved in the transformation of cauliflower curd from white to purple. An expression analysis of these 14 genes in FQ136 material was performed using qRT-PCR, and 9 bHLH genes (BobHLH1, 14, 58, 61, 63, 84, 231, 239 and 243) showed significantly increased or decreased expression in cauliflower from white to purple, which suggests that these 9 genes play important roles in the accumulation of anthocyanins in cauliflower. The coexpression network of these 9 genes and anthocyanin synthesis-related key genes was analyzed using weighted gene coexpression network analysis (WGCNA). In conclusion, our observations suggested that the bHLH gene family plays an important role in the accumulation of anthocyanins in cauliflower and provide an important theoretical basis for further research on the functions of the bHLH gene family and the molecular mechanism of cauliflower coloration.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-022-01238-9.

Genome-wide analysis of serine carboxypeptidase-like protein (SCPL) family and functional validation of Gh_SCPL42 unchromosome conferring cotton Verticillium der Verticillium wilt stress in Gossypium hirsutum

BACKGROUND

Serine carboxypeptidase-like protein (SCPL) plays an important role in response to stress in plant. However, our knowledge of the function of the SCPL gene family is limited.

RESULTS

In this study, a comprehensive and systematic analysis of SCPL gene family was conducted to explore the phylogeny and evolution of the SCPL gene in Gossypium hirsutum. The phenotype and molecular mechanism of silencing of the Gh_SCPL42 under Verticillium wilt stress was also studied. Our results showed that 96 SCPL genes were observed in genome of G. hirsutum, which distributed on 25 chromosomes and most of them were located in the nucleus. The phylogenetic tree analysis showed that members of SCPL gene family can be divided into three subgroups in G. hirsutum, which are relatively conservative in evolution. SCPL gene has a wide range of tissue expression types in G. hirsutum. Promoter analysis showed that the most cis-acting elements related to MeJA and ABA were contained. Through RNA-seq combined with genotyping, it was found that 11 GhSCPL genes not only had significant expression changes during Verticillium wilt stress but also had differential SNPs in the upstream, downstream, exonic or intronic regions. The expression of these 11 genes in the resistant (Zhongzhimian 2) and susceptible (Junmian 1) materials was further analyzed by qRT-PCR, it was found that 6 genes showed significant expression differences in the two materials. Among them, Gh_SCPL42 has the most obvious expression change. Furthermore, virus-induced gene silencing (VIGS) showed necrosis and yellowing of leaves and significantly higher disease severity index (DSI) and disease severity rate (DSR) values in VIGS plants than in control silenced Gh_SCPL42 plants. Moreover, the expression levels of genes related to the SA and JA pathways were significantly downregulated. These results show that Gh_SCPL42 might improve resistance to Verticillium wilt through the SA and JA pathways in G. hirsutum.

CONCLUSION

In conclusion, our findings indicated that Gh_SCPL42 gene plays an important role in resistance to Verticillium wilt in cotton. It was provided an important theoretical basis for further research on the function of SCPL gene family and the molecular mechanism of resistance to Verticillium wilt in cotton.

Gb_ANR-47 Enhances the Resistance of Gossypium barbadense to Fusarium oxysporum f. sp. vasinfectum (FOV) by Regulating the Content of Proanthocyanidins

Anthocyanidin reductase (ANR) is an important regulator of flavonoid metabolism, and proanthocyanidins, the secondary metabolites of flavonoids, play an important role in the response of plants to pathogenic stress. Therefore, in this study, the expression analysis of the ANR gene family of Gossypium barbadense after inoculation with Fusarium oxysporum f. sp. vasinfectum (FOV) was performed at different time points. It was found that Gb_ANR-47 showed significant differences in the disease-resistant cultivar 06-146 and the susceptible cultivar Xinhai 14, as well as in the highest root expression. It was found that the expression of Gb_ANR-47 in the resistant cultivar was significantly higher than that in the susceptible cultivar by MeJA and SA, and different amounts of methyl jasmonate (MeJA) and salicylic acid (SA) response elements were found in the promoter region of Gb_ANR-47. After silencing GbANR-47 in 06-146 material by VIGS technology, its resistance to FOV decreased significantly. The disease severity index (DSI) was significantly increased, and the anthocyanin content was significantly decreased in silenced plants, compared to controls. Our findings suggest that GbANR-47 is a positive regulator of FOV resistance in Gossypium barbadense. The research results provide an important theoretical basis for in-depth analysis of the molecular mechanism of GbANR-47 and improving the anti-FOV of Gossypium barbadense.

Genome-Wide Identification of the SAMS Gene Family in Upland Cotton (Gossypium hirsutum L.) and Expression Analysis in Drought Stress Treatments

Cotton is an important commercial crop whose growth and yield are severely affected by drought. S-adenosylmethionine (SAM) is widely involved in the plant stress response and growth regulation; however, the role of the S-adenosylmethionine synthase (SAMS) gene family in this process is poorly understood. Here, we systematically analyzed the expression of SAMS genes in Upland Cotton (Gossypium hirsutum L.). A total of 16 SAMS genes were identified, each with a similar predicted structure. A large number of cis-acting elements involved in the response to abiotic stress were predicted based on promoter analysis, indicating a likely important role in abiotic stress responses. The results of qRT-PCR validation showed that GhSAMS genes had different expression patterns after drought stress and in response to drought stress. Analysis of a selected subset of GhSAMS genes showed increased expression in cultivar Xinluzhong 39 (drought resistant) when compared to cultivar Xinluzao 26 (drought-sensitive) upland cotton. This study provides important relevant information for further study of SAMS genes in drought resistance research of upland cotton, which is helpful for drought-resistance improvement of upland cotton.

DUF1005 Family Identification, Evolution Analysis in Plants, and Primary Root Elongation Regulation of CiDUF1005 From Caragana intermedia

Proteins with a domain of unknown function (DUF) represent a number of gene families that encode functionally uncharacterized proteins in eukaryotes. In particular, members of the DUF1005 family in plants have a 411-amino-acid conserved domain, and this family has not been described previously. In this study, a total of 302 high-confidence DUF1005 family members were identified from 58 plant species, and none were found in the four algae that were selected. Thus, this result showed that DUF1005s might belong to a kind of plant-specific gene family, and this family has not been evolutionarily expanded. Phylogenetic analysis showed that the DUF1005 family genes could be classified into four subgroups in 58 plant species. The earliest group to emerge was Group I, including a total of 100 gene sequences, and this group was present in almost all selected species spanning from mosses to seed plants. Group II and Group III, with 69 and 74 members, respectively, belong to angiosperms. Finally, with 59 members, Group IV was the last batch of genes to emerge, and this group is unique to dicotyledons. Expression pattern analysis of the CiDUF1005, a member of the DUF1005 family from Caragana intermedia, showed that CiDUF1005 genes were differentially regulated under various treatments. Compared to the wild type, transgenic lines with heterologous CiDUF1005 expression in Arabidopsis thaliana had longer primary roots and more lateral roots. These results expanded our knowledge of the evolution of the DUF1005 family in plants and will contribute to elucidating biological functions of the DUF1005 family in the future.

Genome-Wide Identification and Expression Profiling of DUF221 Gene Family Provides New Insights Into Abiotic Stress Responses in Potato

The domain of the unknown function 221 proteins regulate several processes in plants, including development, growth, hormone transduction mechanism, and abiotic stress response. Therefore, a comprehensive analysis of the potato genome was conducted to identify the deafness-dystonia peptide (DDP) proteins' role in potatoes. In the present study, we performed a genome-wide analysis of the potato domain of the unknown function 221 (DUF221) genes, including phylogenetic inferences, chromosomal locations, gene duplications, gene structures, and expression analysis. In our results, we identified 10 DDP genes in the potato genome. The phylogenetic analysis results indicated that StDDPs genes were distributed in all four clades, and clade IV was the largest clade. The gene duplication under selection pressure analysis indicated various positive and purifying selections in StDDP genes. The putative stu-miRNAs from different families targeting StDDPs were also predicted in the present study. Promoter regions of StDDP genes contain different cis-acting components involved in multiple stress responses, such as phytohormones and abiotic stress-responsive factors. The analysis of the tissue-specific expression profiling indicated the StDDPs gene expression in stem, root, and leaf tissues. We subsequently observed that StDDP4, StDDP5, and StDDP8 showed higher expressions in roots, stems, and leaves. StDDP5 exhibited high expression against heat stress response, and StDDP7 showed high transcript abundance against salt stress in potatoes. Under abscisic acid (ABA) and indole acetic acid (IAA) treatments, seven StDDP genes' expressions indicated that ABA and IAA performed important roles in immunity response. The expression profiling and real-time qPCR of stems, roots, and leaves revealed StDDPs' significant role in growth and development. These expression results of DDPs are primary functional analysis and present basic information for other economically important crops.

The DUF221 domain-containing (DDP) genes identification and expression analysis in tomato under abiotic and phytohormone stress

The domain of unknown function (DUF221 domain-containing) proteins regulates various aspects of plant growth, development, responses to abiotic stresses, and hormone transduction pathways. To understand the role of DDP proteins in tomato, a comprehensive genome-wide analysis was performed in the tomato genome. A total of 12 DDP genes were identified and distributed in 8 chromosomes in the tomato genome. Phylogenetically all SlDDPs were clustered into four clades, subsequently supported by their gene structure and conserved motifs distribution. The SlDDPs contained various cis-acting elements involved in plant responses to abiotic and various phytohormones stresses. The tissue-specific expression profile analysis revealed the constitutive expression of SlDDPs in roots, leaves, and developmental phases of fruit. It was found that SlDDP1, SlDDP3, SlDDP4, SlDDP9, SlDDP10, and SlDDP12 exhibited high expression levels in fruits at different development stages. Of these genes, SlDDP12 contained ethylene (ERE) responsive elements in their promoter regions, suggesting its role in ethylene-dependent fruit ripening. It was found that a single SlDDP induced by two or more abiotic and phytohormone stresses. These include, SlDDP1, SlDDP2, SlDDP3, SlDDP4, SlDDP7, SlDDP8, and SlDDP10 was induced under salt, drought, ABA, and IAA stresses. Moreover, tomato SlDDPs were targeted by multiple miRNA gene families as well. In conclusion, this study predicted that the putative DDP genes might help improve abiotic and phytohormone tolerance in plants, particularly tomato, rice, and other economically important crop plant species.