GhTKPR1_8 functions to inhibit anther dehiscence and reduce pollen viability in cotton.

Sporopollenin, as the main component of the pollen exine, is a highly resistant polymer that provides structural integrity under unfavourable environmental conditions. Tetraketone α-pyrone reductase 1 (TKPR1) is essential for sporopollenin formation, catalyzing the reduction of tetraketone carbonyl to hydroxylated α-pyrone. The functional role of TKPR1 in male sterility has been reported in flowering plants such as maize, rice, and Arabidopsis. However, the molecular cloning and functional characterization of TKPR1 in cotton remain unaddressed. In this study, we identified 68 TKPR1s from four cotton species, categorized into three clades. Transcriptomics and RT-qPCR demonstrated that GhTKPR1_8 exhibited typical expression patterns in the tetrad stage of the anther. GhTKPR1_8 was localized to the endoplasmic reticulum. Moreover, ABORTED MICROSPORES (GhAMS) transcriptionally activated GhTKPR1_8 as indicated by luciferase complementation tests. GhTKPR1_8-knockdown inhibited anther dehiscence and reduced pollen viability in cotton. Additionally, overexpression of GhTKPR1_8 in the attkpr1 mutant restored its male sterile phenotype. This study offers novel insights into the investigation of TKPR1 in cotton while providing genetic resources for studying male sterility.

GhSTP18, a member of sugar transport proteins family, negatively regulates salt stress in cotton.

The sugar transporter protein (STP) family has been shown to play important roles in plant growth, development, and stress response. However, it has not been studied in cotton compared to other major crops. In this study, we identified 90 STP genes from four cotton species, performed bioinformatic analysis, and focused on the role of GhSTP18 in salt stress. According to our results, cotton STP proteins were divided into four subgroups according to the phylogenetic tree. A synteny analysis suggested that whole-genome duplication (WGD) and segmental duplication were key drivers in the expansion of the STP gene family. The transcriptomic data analysis showed that 29 GhSTP genes exhibited sink-specific expression. Quantitative real time-polymerase chain reaction (qRT-PCR) analyses revealed that expression of GhSTP18 was induced by salt treatment, heat treatment, cold treatment, and drought treatment, and continuously increased during a salt stress time course. Notably, GhSTP18 encodes a plasma membrane-localized galactose transporter. Suppression of GhSTP18 transcription by a virus-induced gene silencing (VIGS) assay reduced sensitivity to salt stress in cotton, indicating that GhSTP18 negatively regulates plant salt tolerance. These results provide an important reference and resource for further studying and deploying STP genes for cotton improvement.

Recombinant-attenuated Salmonella enterica serovar Choleraesuis vector expressing the PlpE protein of Pasteurella multocida protects mice from lethal challenge.

BACKGROUND: Bacterial surface proteins play key roles in pathogenicity and often contribute to microbial adhesion and invasion. Pasteurella lipoprotein E (PlpE), a Pasteurella multocida (P. multocida) surface protein, has recently been identified as a potential vaccine candidate. Live attenuated Salmonella strains have a number of potential advantages as vaccine vectors, including immunization with live vector can mimic natural infections by organisms, lead to the induction of mucosal, humoral, and cellular immune responses. In this study, a previously constructed recombinant attenuated Salmonella Choleraesuis (S. Choleraesuis) vector rSC0016 was used to synthesize and secrete the surface protein PlpE of P. multocida to form the vaccine candidate rSC0016(pS-PlpE). Subsequently, the immunogenicity of S. Choleraesuis rSC0016(pS-PlpE) as an oral vaccine to induce protective immunity against P. multocida in mice was evaluated. RESULTS: After immunization, the recombinant attenuated S. Choleraesuis vector can efficiently delivered P. multocida PlpE protein in vivo and induced a specific immune response against this heterologous antigen in mice. In addition, compared with the inactivated vaccine, empty vector (rSC0016(pYA3493)) and PBS immunized groups, the rSC0016(pS-PlpE) vaccine candidate group induced higher antigen-specific mucosal, humoral and mixed Th1/Th2 cellular immune responses. After intraperitoneal challenge, the rSC0016(pS-PlpE) immunized group had a markedly enhanced survival rate (80%), a better protection efficiency than 60% of the inactivated vaccine group, and significantly reduced tissue damage. CONCLUSIONS: In conclusion, our study found that the rSC0016(pS-PlpE) vaccine candidate provided good protection against challenge with wild-type P. multocida serotype A in a mouse infection model, and may potentially be considered for use as a universal vaccine against multiple serotypes of P. multocida in livestock, including pigs.

Expressed genes and their new alleles identification during fibre elongation reveal the genetic factors underlying improvements of fibre length in cotton.

Interspecific breeding in cotton takes advantage of genetic recombination among desirable genes from different parental lines. However, the expression new alleles (ENAs) from crossovers within genic regions and their significance in fibre length (FL) improvement are currently not understood. Here, we generated resequencing genomes of 191 interspecific backcross inbred lines derived from CRI36 (Gossypium hirsutum) × Hai7124 (Gossypium barbadense) and 277 dynamic fibre transcriptomes to identify the ENAs and extremely expressed genes (eGenes) potentially influencing FL, and uncovered the dynamic regulatory network of fibre elongation. Of 35 420 eGenes in developing fibres, 10 366 ENAs were identified and preferentially distributed in chromosomes subtelomeric regions. In total, 1056-1255 ENAs showed transgressive expression in fibres at 5-15 dpa (days post-anthesis) of some BILs, 520 of which were located in FL-quantitative trait locus (QTLs) and GhFLA9 (recombination allele) was identified with a larger effect for FL than GhFLA9 of CRI36 allele. Using ENAs as a type of markers, we identified three novel FL-QTLs. Additionally, 456 extremely eGenes were identified that were preferentially distributed in recombination hotspots. Importantly, 34 of them were significantly associated with FL. Gene expression quantitative trait locus analysis identified 1286, 1089 and 1059 eGenes that were colocalized with the FL trait at 5, 10 and 15 dpa, respectively. Finally, we verified the Ghir_D10G011050 gene linked to fibre elongation by the CRISPR-cas9 system. This study provides the first glimpse into the occurrence, distribution and expression of the developing fibres genes (especially ENAs) in an introgression population, and their possible biological significance in FL.

GhN/AINV13 positively regulates cotton stress tolerance by interacting with the 14-3-3 protein.

Neutral/alkaline invertases (N/AINVs) are sucrose hydrolases with important roles in plants. In this study, 15, 15, 15, 29, and 30 N/AINVs were identified in the Gossypium species, G. raimondii, G. herbaceum, G. arboreum, G. hirsutum, and G. barbadense, respectively. Along with two previously discovered branches, α and ß, a new clade γ was first discovered in our study. Investigation of gene collinearity showed that whole-genome duplication (WGD) and polyploidization were responsible for the expansion of the N/AINV gene family in allopolyploid Gossypium. Moreover, expression patterns revealed that GhN/AINV3/13/17/23/24/28 from the ß clade is highly expressed during the period of fiber initiation. The invertase activity of GhN/AINV13 and GhN/AINV23 were confirmed by restoring defects of invertase-deficient yeast mutant SEY2102. Treatments of abiotic stress showed that most GhN/AINVs were induced in response to polyethylene glycol (PEG) or salt stress. A virus-induced gene-silencing (VIGS) experiment and yeast two-hybrid assay demonstrated that GhN/AINV13 may interact with their positive regulators Gh14-3-3 proteins and participate in the fiber initiation or stress tolerance of cotton. Our results provided fundamental information regarding N/AINVs and highlight their potential functions in cotton stress tolerance.

GhTULP34, a member of tubby-like proteins, interacts with GhSKP1A to negatively regulate plant osmotic stress.

Tubby-like protein genes (TULPs), present in the form of large multigene families, play important roles in environmental stress. However, little is known regarding the TULP family genes in cotton. In this study, we systematically identified and analyzed the membership, characterization, and evolutionary relationship of TULPs in four species of cotton. Transcriptome analysis indicated that GhTULPs participate in environmental stress and cotton tissue development. At the same time, we also predicted and analyzed the potential molecular regulatory mechanisms and functions of TULPs. GhTULP34, as a candidate gene, significantly reduced the germination rate of transgenic Arabidopsis plants under salt stress, and inhibited root development and stomatal closure under mannitol stress. The yeast two-hybrid and luciferase (LUC) systems showed that GhTULP34 can interact with GhSKP1A, a subunit of the SCF-type (Skp1-Cullin-1-F-box) complex. This study will provide a basis and reference for future research on their roles in stress tolerance.

GhBOP1 as a Key Factor of Ribosomal Biogenesis: Development of Wrinkled Leaves in Upland Cotton.

Block of proliferation 1 (BOP1) is a key protein that helps in the maturation of ribosomes and promotes the progression of the cell cycle. However, its role in the leaf morphogenesis of cotton remains unknown. Herein, we report and study the function of GhBOP1 isolated from Gossypium hirsutum. The sequence alignment revealed that BOP1 protein was highly conserved among different species. The yeast two-hybrid experiments, bimolecular fluorescence complementation, and luciferase complementation techniques revealed that GhBOP1 interact with GhPES and GhWDR12. Subcellular localization experiments revealed that GhBOP1, GhPES and GhWDR12 were localized at the nucleolus. Suppression of GhBOP1 transcripts resulted in the uneven bending of leaf margins and the presence of young wrinkled leaves by virus-induced gene silencing assay. Abnormal palisade arrangements and the presence of large upper epidermal cells were observed in the paraffin sections of the wrinkled leaves. Meanwhile, a jasmonic acid-related gene, GhOPR3, expression was increased. In addition, a negative effect was exerted on the cell cycle and the downregulation of the auxin-related genes was also observed. These results suggest that GhBOP1 plays a critical role in the development of wrinkled cotton leaves, and the process is potentially modulated through phytohormone signaling.

Identification and characterization of the AINV genes in five Gossypium species with potential functions of GhAINVs under abiotic stress.

Acid invertase (AINV) is a kind of sucrose hydrolase with an important role in plants. Currently, the AINV genes have not been systematically studied in cotton. In this study, a total of 92 AINV genes were identified in five cotton species. The phylogenetic analysis revealed that the AINV proteins were divided into two subgroups in cotton: vacuolar invertase (VINV) and cell wall invertase (CWINV). The analysis of gene structures, conserved motifs, and three-dimensional protein structures suggested that GhAINVs were significantly conserved. The synteny analysis showed that whole-genome duplication was the main force promoting the expansion of the AINV gene family. The cis-element, transcriptome, and quantitative real time-polymerase chain reaction (qRT-PCR) showed that some GhAINVs were possibly associated with stress response. GhCWINV4, highly expressed in PEG treatment, was cloned, and subsequent virus-induced gene silencing assay confirmed that this gene was involved in the drought stress response. Overall, this study might be helpful for further analyzing the biological function of AINVs and provide clues for improving the resistance of cotton to stress.

QTL analysis and candidate gene identification for plant height in cotton based on an interspecific backcross inbred line population of Gossypium hirsutum × Gossypium barbadense.

KEY MESSAGE: We constructed the first high-quality and high-density genetic linkage map for an interspecific BIL population in cotton by specific-locus amplified fragment sequencing for QTL mapping. A novel gene GhPIN3 for plant height was identified in cotton. Ideal plant height (PH) is important for improving lint yield and mechanized harvesting in cotton. Most published genetic studies on cotton have focused on fibre yield and quality traits rather than PH. To facilitate the understanding of the genetic basis in PH, an interspecific backcross inbred line (BIL) population of 250 lines derived from upland cotton (Gossypium hirsutum L.) CRI36 and Egyptian cotton (G. barbadense L.) Hai7124 was used to construct a high-density genetic linkage map for quantitative trait locus (QTL) mapping. The high-density genetic map harboured 7,709 genotyping-by-sequencing (GBS)-based single nucleotide polymorphism (SNP) markers that covered 3,433.24 cM with a mean marker interval of 0.67 cM. In total, ten PH QTLs were identified and each explained 4.27-14.92% of the phenotypic variation, four of which were stable as they were mapped in at least two tests or based on best linear unbiased prediction in seven field tests. Based on functional annotation of orthologues in Arabidopsis and transcriptome data for the genes within the stable QTL regions, GhPIN3 encoding for the hormone auxin efflux carrier protein was identified as a candidate gene located in the stable QTL qPH-Dt1-1 region. A qRT-PCR analysis showed that the expression level of GhPIN3 in apical tissues was significantly higher in four short-statured cotton genotypes than that in four tall-statured cotton genotypes. Virus-induced gene silencing cotton has significantly increased PH when the expression of the GhPIN3 gene was suppressed.

Genetic variation of dynamic fiber elongation and developmental quantitative trait locus mapping of fiber length in upland cotton (Gossypium hirsutum L.).

BACKGROUND: In upland cotton (Gossypium hirsutum L.), genotypes with the same mature fiber length (FL) might possess different genes and exhibit differential expression of genes related to fiber elongation at different fiber developmental stages. However, there is a lack of information on the genetic variation influencing fiber length and its quantitative trait loci (QTLs) during the fiber elongation stage. In this study, a subset of upland cotton accessions was selected based on a previous GWAS conducted in China and grown in multiple environments to determine the dynamic fiber length at 10, 15, 20, and 25 days post-anthesis (DPA) and maturity. The germplasm lines were genotyped with the Cotton 63 K Illumina single-nucleotide polymorphism (SNP) array for GWAS. RESULTS: A total of 25, 38, 57, 89 and 88 SNPs showed significant correlations with fiber length at 10, 15, 20 and 25 DPA and maturity, respectively. In addition, 60 more promising SNPs were detected in at least two tests and two FL developmental time points, and 20 SNPs were located within the confidence intervals of QTLs identified in previous studies. The fastest fiber-length growth rates were obtained at 10 to 15 DPA in 69 upland cotton lines and at 15 to 20 DPA in 14 upland cotton accessions, and 10 SNPs showed significant correlations with the fiber-length growth rate. A combined transcriptome and qRT-PCR analysis revealed that two genes (D10G1008 and D13G2037) showed differential expression between two long-fiber genotypes and two short-fiber genotypes. CONCLUSIONS: This study provides important new insights into the genetic basis of the time-dependent fiber-length trait and reveals candidate SNPs and genes for improving fiber length in upland cotton.

QTL delineation for five fiber quality traits based on an intra-specific Gossypium hirsutum L. recombinant inbred line population.

Gossypium hirsutum L. is the most important fiber crop worldwide and contributes to more than 95% of global cotton production. Marker-assisted selection (MAS) is an effective approach for improving fiber quality, and quantitative trait loci (QTL) mapping of fiber quality traits is important for cotton breeding. In this study, a permanent intra-specific recombinant inbred line (RIL) population containing 137 families was used for fiber quality testing. Based on a previously reported high-density genetic map with an average marker distance of 0.63 cM, 186 additive QTLs were obtained for five fiber quality traits over five consecutive years, including 39 for fiber length (FL), 36 for fiber strength (FS), 50 for fiber uniformity (FU), 33 for micronaire (MC) and 28 for fiber elongation (FE). Three stable QTLs, qMC-A4-1, qMC-D2-3 and qFS-D9-1, were detected in four datasets, and another eight stable QTLs, qMC-A4-2, qMC-D11-2, qFU-A9-1, qFU-A10-4, qFS-D11-1, qFL-D9-2, qFL-D11-1 and qFE-A3-2, were detected in three datasets. The annotated genes in these 11 stable QTLs were collected, and these genes included many transcription factors with functions during fiber development. 33 QTL coincidence regions were found, and these involved nearly half of the total QTLs. Four chromosome regions containing at least 6 QTLs were promising for fine mapping. In addition, 41 pairs of epistatic QTLs (e-QTLs) were screened, including 6 for FL, 30 for FS, 2 for FU and 3 for MC. The identification of stable QTLs adds valuable information for further QTL fine mapping and gene positional cloning for fiber quality genetic detection and provides useful markers for further molecular breeding in enhancing fiber quality.

Fine mapping and candidate gene analysis of the virescent gene v 1 in Upland cotton (Gossypium hirsutum).

The young leaves of virescent mutants are yellowish and gradually turn green as the plants reach maturity. Understanding the genetic basis of virescent mutants can aid research of the regulatory mechanisms underlying chloroplast development and chlorophyll biosynthesis, as well as contribute to the application of virescent traits in crop breeding. In this study, fine mapping was employed, and a recessive gene (v 1) from a virescent mutant of Upland cotton was narrowed to an 84.1-Kb region containing ten candidate genes. The GhChlI gene encodes the cotton Mg-chelatase I subunit (CHLI) and was identified as the candidate gene for the virescent mutation using gene annotation. BLAST analysis showed that the GhChlI gene has two copies, Gh_A10G0282 and Gh_D10G0283. Sequence analysis indicated that the coding region (CDS) of GhChlI is 1269 bp in length, with three predicted exons and one non-synonymous nucleotide mutation (G1082A) in the third exon of Gh_D10G0283, with an amino acid (AA) substitution of arginine (R) to lysine (K). GhChlI-silenced TM-1 plants exhibited a lower GhChlI expression level, a lower chlorophyll content, and the virescent phenotype. Analysis of upstream regulatory elements and expression levels of GhChlI showed that the expression quantity of GhChlI may be normal, and with the development of the true leaf, the increase in the Gh_A10G0282 dosage may partially make up for the deficiency of Gh_D10G0283 in the v 1 mutant. Phylogenetic analysis and sequence alignment revealed that the protein sequence encoded by the third exon of GhChlI is highly conserved across diverse plant species, in which AA substitutions among the completely conserved residues frequently result in changes in leaf color in various species. These results suggest that the mutation (G1082A) within the GhChlI gene may cause a functional defect of the GhCHLI subunit and thus the virescent phenotype in the v1 mutant. The GhChlI mutation not only provides a tool for understanding the associations of CHLI protein function and the chlorophyll biosynthesis pathway but also has implications for cotton breeding.

iTRAQ-Based Quantitative Proteomic Analysis Reveals Cold Responsive Proteins Involved in Leaf Senescence in Upland Cotton (Gossypium hirsutum L.).

Premature leaf senescence occurs in the ultimate phase of the plant, and it occurs through a complex series of actions regulated by stress, hormones and genes. In this study, a proteomic analysis was performed to analyze the factors that could induce premature leaf senescence in two cotton cultivars. We successfully identified 443 differential abundant proteins (DAPs) from 7388 high-confidence proteins at four stages between non-premature senescence (NS) and premature senescence (PS), among which 158 proteins were over-accumulated, 238 proteins were down-accumulated at four stages, and 47 proteins displayed overlapped accumulation. All the DAPs were mapped onto 21 different categories on the basis of a Clusters of Orthologous Groups (COG) analysis, and 9 clusters were based on accumulation. Gene Ontology (GO) enrichment results show that processes related to stress responses, including responses to cold temperatures and responses to hormones, are significantly differentially accumulated. More importantly, the enriched proteins were mapped in The Arabidopsis Information Resource (TAIR), showing that 58 proteins play an active role in abiotic stress, hormone signaling and leaf senescence. Among these proteins, 26 cold-responsive proteins (CRPs) are significantly differentially accumulated. The meteorological data showed that the median temperatures declined at approximately 15 days before the onset of aging, suggesting that a decrease in temperature is tightly linked to an onset of cotton leaf senescence. Because accumulations of H2O2 and increased jasmonic acid (JA) were detected during PS, we speculate that two pathways associated with JA and H2O2 are closely related to premature leaf senescence in cotton.

High-density linkage map construction and QTL analysis for earliness-related traits in Gossypium hirsutum L.

BACKGROUND: Gossypium hirsutum L., or upland cotton, is an important renewable resource for textile fiber. To enhance understanding of the genetic basis of cotton earliness, we constructed an intra-specific recombinant inbred line population (RIL) containing 137 lines, and performed linkage map construction and quantitative trait locus (QTL) mapping. RESULTS: Using restriction-site associated DNA sequencing, a genetic map composed of 6,434 loci, including 6,295 single nucleotide polymorphisms and 139 simple sequence repeat loci, was developed from RIL population. This map spanned 4,071.98 cM, with an average distance of 0.63 cM between adjacent markers. A total of 247 QTLs for six earliness-related traits were detected in 6 consecutive years. In addition, 55 QTL coincidence regions representing more than 60 % of total QTLs were found on 22 chromosomes, which indicated that several earliness-related traits might be simultaneously improved. Fine-mapping of a 2-Mb region on chromosome D3 associated with five stable QTLs between Marker25958 and Marker25963 revealed that lines containing alleles derived from CCRI36 in this region exhibited smaller phenotypes and earlier maturity. One candidate gene (EMF2) was predicted and validated by quantitative real-time PCR in early-, medium- and late-maturing cultivars from 3- to 6-leaf stages, with highest expression level in early-maturing cultivar, CCRI74, lowest expression level in late-maturing cultivar, Bomian1. CONCLUSIONS: We developed an SNP-based genetic map, and this map is the first high-density genetic map for short-season cotton and has the potential to provide deeper insights into earliness. Cotton earliness-related QTLs and QTL coincidence regions will provide useful materials for QTL fine mapping, gene positional cloning and MAS. And the gene, EMF2, is promising for further study.

[Determination of 8 hindered phenolic antioxidantsin olive oil by ultra-performance liquid chromatography and its migration research].

OBJECTIVE: To develop a method for determination of PG, TBHQ, NDGA, BHA, Ionox100, OG, DG and BHT in olive oil by ultra-performance liquid chromatography (UPLC), and to study the migration rule of hindered phenolic antioxidants in food simulation solvent. METHODS: The samples were extracted with acetonitrile, and C18 dispersion matrix solid-phase, the separation were performed by UPLC. The migration amount of PG, BHA, BHT from polyethylene film to different simulated solvent (olive oil, 20% ethanol, 10% ethanol, 3% acetic acid) were determined at 20, 60 and 100 degrees C. RESULTS: The retention time of 8 hindered phenolic antioxidants was less than 8.5 min. The limits of detection were in the range of 0.01 - 0.05 µg/mL, and the linear correlations were > 0.999. The average recoveries were from 80.0% to 106.8%, and the relative standard deviations were between 0.69% and 7.94%. The original heating migration experiments of PG, BHA and BHT were performed by such method. As the extension of heating time, the migration amounts were increased, and the migration amounts of PG in water-based food simulation solvent was similar in olive oil. BHA and BHT easily migrated to simulate fat solvents. The migration amount was the maximum in olive oil, while the migration amounts of BHA and BHT were little as the ethanol decreased in other simulation solvents. The migration amount of BHA in 20% ethanol was more than in 10% ethanol and 3% acetic acid. CONCLUSION: With the increase of temperature, the migration amount increase, and the hindered phenolic antioxidants easily migrate to simulate fat solvents.

Genome-wide analysis of the family 1 glycosyltransferases in cotton.

Family 1 GT, designated as UGT, is the largest and most functionally important multigene family in the plant kingdom. In this study, we carried out a genome-wide identification, analysis, and comparison of 142, 146, and 196 putative UGTs from Gossypium raimondii, Gossypium arboreum, and Gossypium hirsutum, respectively. All members present the 44 amino-acid conserved consensus sequence termed the plant secondary product glycosyltransferase motif. According to the phylogenetic relationship among the cotton UGT proteins and those from other species, GrUGTs and GaUGTs could be classified into 16 major phylogenetic groups (A-P), whereas GhUGTs are classified into 15 major phylogenetic groups with a lack of group C. All cotton UGTs are dispersed throughout the chromosomes and are displayed in clusters with the same open reading frame orientation. The expansion of them appears to result from genome duplication and rearrangement. Two conserved introns, A and B, are detected in most of the intron-containing-UGTs in G. raimondii and G. arboreum, whereas only intron A is detected in the intron-containing-UGTs in G. hirsutum. Furthermore, expression patterns of the UGT genes in G. hirsutum wild type and its near isogenic fuzzless-lintless mutant at the stage of fiber initiation were analyzed using the RNA-seq data. Overall, this study not only deepens our understanding of the structure, phylogeny, evolution, and expression of cotton UGT genes, but also provides a solid foundation for further cloning and functional studies of the UGT family genes.

Quantitative phosphoproteomic profiling of fiber differentiation and initiation in a fiberless mutant of cotton.

BACKGROUND: The cotton (Gossypium spp.) fiber cell is an important unicellular model for studying cell differentiation. There is evidence suggesting that phosphorylation is a critical post-translational modification involved in regulation of a wide range of cell activities. Nevertheless, the sites of phosphorylation in G. hirsutum and their regulatory roles in fiber cell initiation are largely unknown. In this study, we employed a mass spectrometry-based phosphoproteomics to conduct a global and site-specific phosphoproteome profiling between ovules of a fuzzless-lintless (fl) Upland cotton (G. hirsutum) mutant and its isogenic parental wild type (WT) at -3 and 0 days post-anthesis (DPA). RESULTS: A total of 830 phosphopeptides and 1,592 phosphorylation sites from 619 phosphoproteins were identified by iTRAQ (isobaric tags for relative and absolute quantitation). Of these, 76 phosphoproteins and 1,100 phosphorylation sites were identified for the first time after searching the P3DB public database using the BLAST program. Among the detected phosphopeptides, 69 were differentially expressed between the fl mutant and its WT in ovules at -3 and 0 DPA. An analysis using the Motif-X program uncovered 19 phosphorylation motifs, 8 of which were unique to cotton. A further metabolic pathway analysis revealed that the differentially phosphorylated proteins were involved in signal transduction, protein modification, carbohydrate metabolic processes, and cell cycle and cell proliferation. CONCLUSIONS: Our phosphoproteomics-based research provides the first global overview of phosphorylation during cotton fiber initiation, and also offers a helpful dataset for elucidation of signaling networks in fiber development of G. hirsutum.

Identification of cotton PIP5K genes and role of GhPIP5K9a in primary root development.

Phosphatidylinositol 4 phosphate 5-kinase (PIP5K) is crucial for the phosphatidylinositol (PI) signaling pathway. It plays a significant role in plant growth and development, as well as stress response. However, its effects on cotton are unknown. This study identified PIP5K genes from four cotton species and conducted bioinformatic analyses, with a particular emphasis on the functions of GhPIP5K9a in primary roots. The results showed that cotton PIP5Ks were classified into four subgroups. Analysis of gene structure and motif composition showed obvious conservation within each subgroup. Synteny analysis suggested that the PIP5K gene family experienced significant expansion due to both whole-genome duplication (WGD) and segmental duplication. Transcriptomic data analysis revealed that the majority of GhPIP5K genes had the either low or undetectable levels of expression. Moreover, GhPIP5K9a is highly expressed in the root and was located in plasmalemma. Suppression of GhPIP5K9a transcripts resulted in longer primary roots, longer primary root cells and increased auxin polar transport-related genes expression, and decreased abscisic acid (ABA) content, indicating that GhPIP5K9a negatively regulates cotton primary root growth. This study lays the foundation for further exploration of the role of the PIP5K genes in cotton.

Exploring the role of GhN/AINV23: implications for plant growth, development, and drought tolerance.

BACKGROUND: Neutral/alkaline invertases (N/AINVs) play a crucial role in plant growth, development, and stress response, by irreversibly hydrolyzing sucrose into glucose and fructose. However, research on cotton in this area is limited. This study aims to investigate GhN/AINV23, a neutral/alkaline invertase in cotton, including its characteristics and biological functions. RESULTS: In our study, we analyzed the sequence information, three-dimensional (3D) model, phylogenetic tree, and cis-elements of GhN/AINV23. The localization of GhN/AINV23 was determined to be in the cytoplasm and cell membrane. Quantitative real-time polymerase chain reaction (qRT-PCR) results showed that GhN/AINV23 expression was induced by abscisic acid (ABA), exogenous sucrose and low exogenous glucose, and inhibited by high exogenous glucose. In Arabidopsis, overexpression of GhN/AINV23 promoted vegetative phase change, root development, and drought tolerance. Additionally, the virus-induced gene silencing (VIGS) assay indicated that the inhibition of GhN/AINV23 expression made cotton more susceptible to drought stress, suggesting that GhN/AINV23 positively regulates plant drought tolerance. CONCLUSION: Our research indicates that GhN/AINV23 plays a significant role in plant vegetative phase change, root development, and drought response. These findings provide a valuable foundation for utilizing GhN/AINV23 to improve cotton yield.

The disruption of LPS in Salmonella Typhimurium provides partial protection against Salmonella Choleraesuis as a live attenuated vaccine.

Interference with the normal synthesis of LPS was shown to enhance immune responses to conserved outer membrane proteins. In the present study, we have constructed three vaccine candidates by deleting four genes (rfaL, rfbB, rffG and wzy) associated with LPS synthesis in the wild-type strain UK-1. Virulence assessment showed that after oral immunization of BALB/c mice, all mutant strains were attenuated and had significantly reduced ability to colonize host tissues compared to the wild-type strain. In addition, all three vaccine candidates induced elevated humoral, mucosal and cellular immune responses against S. Typhimurium and S. Choleraesuis OMPs compared to the PBS-treated group. Finally, immunization of mice with the rSC0136 vaccine candidate strain provided 100 % and 40 % protection against S. Typhimurium and S. Choleraesuis challenge, respectively. These results suggest that the deletion of LPS synthesis-related genes may be an effective strategy against homologous serotypes, but provides only partial protection against heterologous serotypes.