Metabolic profile analysis based on GC-TOF/MS and HPLC reveals the negative correlation between catechins and fatty acids in the cottonseed of Gossypium hirsutum

Background: The diversified and high value-added utilization of cotton by products can promote the sustainable development of modern agriculture. Di erences in potential nutrients among varieties can be explained by variations in the composition and abundance of fatty acids, polyphenols, carbohydrates, amino acids, and organic acids. Therefore, the analysis of metabolite species and relationships in cottonseed is meaningful for the development of cotton byproducts.Results: In this study, the metabolomes of three representative cotton cultivars of di erent species were compared using untargeted GC-TOF/MS analysis. A total of 263 metabolites were identified from 705 peaks, and their levels were compared across cultivars. Principal component analysis and OPLS-DA clearly distinguish these samples based on metabolites. There were significant di erences in the contents of amino acids, carbohydrates, organic acids, flavonoids, and lipids in G. hirsutum TM-1 compared with G. arboreum Shixiya1 and G. barbadense Hai7124. Notably, the bioactive nutrient compound catechin obtained from the di erential metabolites significantly accumulated in TM-1. Furthermore, a comprehensive analysis using catechin and oil-related traits was conducted in core collections of Gossypium hirsutum. The results revealed the reliability of the GC-TOF/MS analysis, as well as that catechin content has a negative association with myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, and total fatty acids.Conclusion: These findings suggest that untargeted GC-TOF/MS analysis could provide a new method for investigating the underlying plant biochemistry of nutrient variation in cottonseed, and that catechin content has a negative association with oil-related traits in cottonseed. This study may pave the way to exploit the value of cotton byproducts.

Identification and expression analysis of Tubulin gene family in upland cotton

Background:Cott on fibers are single-celled exte nsions of the seed epidermis,a model tissue for studying cytoskeleton.Tubulin genes play a critical role in synthesizing the microtubules(MT)as a core element of the cytoskeleton.However,there is a lack of studies concerning the systematic characterization of the tubulin gene family in cotton.Therefore,the identification and portrayal of G.hirsutum tubulin genes can provide key targets for molecular manipulation in cotton breeding.Result:In this study,we investigated all tubulin genes from different plant species and identified 98 tubulin genes in G.hirsutum.Phylogenetic an a lysis showed that tubulin family genes were classified into three subfamilies.The protein motifs and gene structure ofβ-tubulin genes are more conserved compared withγ-tubulin genes.Most tubulin genes are located at the proximate ends of the chromosomes.Spatiotemporal expression pattern by transcriptome and qRT-PCR analysis revealed that 12α-tubulin andβ-tubulin genes are specifically expressed during different fiber development stages.However,Gh.A03G027200,Gh.D03G 169300,and Gh.A1lG258900 had differential expression patterns at distinct stages of fiber development in varieties JO2508 and ZRI015.Conclusion:In this study,the evol ut io nary an alysis showed that the tubulin genes were divided into three clades.The genetic structures and molecular functions were highly con served in different plants.Three candidate genes,Gh.A03G027200f Gh.D03G169300,and Gh.A11G258900 may play a key role during fiber development complementing fiber length and strength.

QTL mapping for plant height and fruit branch number based on RIL population of upland cotton

Background:Plant height(PH)and fruit branch number(FBN)are important traits for improving yield and mechanical harvesting of cotton.In order to identify genes of PH and FBN in cotton germplasms to develop superior cultivars,quantitative trait loci(QTLs)for these traits were detected based on the phenotypic evaluation data in nine environments across four locations and 4 years and a previously reported genetic linkage map of an recombinant inbred line(RIL)population of upland cotton.Results:In total,53 QTLs of PH and FBN,were identified on 21 chromosomes of the cotton genome except chromosomes c02,c09-c11,and c22.For PH,27 QTLs explaining 3.81%–8.54%proportions of phenotypic variance were identified on 18 chromosomes except c02,c08-c12,c15,and c22.For FBN,26 QTLs explaining 3.23%–11.00%proportions of phenotypic variance were identified on 16 chromosomes except c02-c03,c06,c09-c11,c17,c22-c23,and c25.Eight QTLs were simultaneously identified in at least two environments.Three QTL clusters containing seven QTLs were identified on three chromosomes(c01,c18 and c21).Eleven QTLs were the same as previously reported ones,while the rest were newly identified.Conclusions:The QTLs and QTL clusters identified in the current study will be helpful to further understand the genetic mechanism of PH and FBN development of cotton and will enhance the development of excellent cultivars for mechanical managements in cotton production.

Comparative transcriptional analysis provides insights of possible molecular mechanisms of wing polyphenism induced by postnatal crowding in Aphis gossypii

Background:Aphis gossypii is a worldwide sap-sucking pest with a variety of hosts and a vector of more than 50 plant viruses.The strategy of wing polyphenism,mostly resulting from population density increasing,contributes to the evolutionary success of this pest.However,the related molecular basis remains unclear.Here,we identified the effects of postnatal crowding on wing morph determination in cotton aphid,and examined the transcriptomic differences between wingless and wing morphs.Results:Effect of postnatal crowding on wing determination in A gossypii was evaluated firstly.Under the density of 5 nymphs·cm-2,no wing aphids appeared.Proportion of wing morphs rised with the increase of density in a certain extent,and peaked to 56.1% at the density of 20 nymphs·cm-2,and reduced afterwards.Then,transcriptomes of wingless and wing morphs were assembled and annotated separately to identify potentially exclusively or differentially expressed transcripts between these two morphs,in which 3 126 and 3 392 unigenes annotated in Nr(Non-redundant protein sequence) database were found in wingless or wing morphs exclusively.Moreover,3 187 up-and 1 880 down-regulated genes were identified in wing versus wingless aphid.Pathways analysis suggested the involvement of differentially expressed genes in multiple cellular signaling pathways involved in wing morphs determination,including lipid catabolic and metabolism,insulin,ecdysone and juvenile hormone biosynthesis.The expression levels of related genes were validated by the reverse transcription quantitative real time polymerase chain reaction(RT-qPCR) soon afterwards.Conclusions:The present study identified the effects of postnatal crowding on wing morphs induction and demonstrated that the critical population density for wing morphs formation in A gossypii was 20 nymphs·cm-2.Comparative transcriptome analysis provides transcripts potentially expressed exclusively in wingless or wing morph,respectively.Differentially expressed genes between wingless and wing morphs were identified and several signaling pathways potentially involved in cotton aphid wing differentiation were obtained.