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1.
Front Plant Sci ; 12: 766130, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956264

RESUMO

Low temperature is a common biological abiotic stress in major cotton-growing areas. Cold stress significantly affects the growth, yield, and yield quality of cotton. Therefore, it is important to develop more robust and cold stress-resilient cotton germplasms. In response to climate change and erratic weather conditions, plants have evolved various survival mechanisms, one of which involves the induction of various stress responsive transcript factors, of which the C-repeat-binding factors (CBFs) have a positive effect in enhancing plants response to cold stress. In this study, genomewide identification and functional characterization of the cotton CBFs were carried out. A total of 29, 28, 25, 21, 30, 26, and 15 proteins encoded by the CBF genes were identified in seven Gossypium species. A phylogenetic evaluation revealed seven clades, with Clades 1 and 6 being the largest. Moreover, the majority of the proteins encoded by the genes were predicted to be located within the nucleus, while some were distributed in other parts of the cell. Based on the transcriptome and RT-qPCR analysis, Gthu17439 (GthCBF4) was highly upregulated and was further validated through forward genetics. The Gthu17439 (GthCBF4) overexpressed plants exhibited significantly higher tolerance to cold stress, as evidenced by the higher germination rate, increased root growth, and high-induction levels of stress-responsive genes. Furthermore, the overexpressed plants under cold stress had significantly reduced oxidative damage due to a reduction in hydrogen peroxide (H2O2) production. Moreover, the overexpressed plants under cold stress had minimal cell damage compared to the wild types, as evidenced by the Trypan and 3,3'-Diaminobenzidine (DAB) staining effect. The results showed that the Gthu17439 (GthCBF4) could be playing a significant role in enhancing cold stress tolerance in cotton and can be further exploited in developing cotton germplasm with improved cold-stress tolerance.

2.
Artigo em Inglês | MEDLINE | ID: mdl-34769821

RESUMO

Promoting the intention of farmers to participate in straw recycling is an effective way to alleviate the contradiction between environmental pollution, scarcity of environmental resources, and sustainable development. In this study, social trust and value perception were integrated into the theory of planned behavior to build a theoretical framework of farmers' intention to participate in straw recycling, considering the influences of three different pro-environmental publicity modes. A field investigation was used to collect research data in six sample villages. Finally, 761 valid questionnaires were collected, and partial least squares structural equation modeling was applied to test the research hypotheses. The results showed that the influence of attitudes, subjective norms, perceived behavior control, value perception, and social trust on farmers' straw recycling intentions was different among different pro-environmental publicity modes. Among the three pro-environmental publicity modes, the concentrated pro-environmental publicity mode has the best effect of promoting straw recycling intentions among farmers. This study introduces some targeted suggestions on the aspects of pro-environmental publicity theory and management practice based on the above research results.


Assuntos
Fazendeiros , Intenção , Agricultura , Atitude , Controle Comportamental , Humanos , Inquéritos e Questionários
3.
Front Plant Sci ; 12: 746771, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34745180

RESUMO

Cotton is one of the most important fiber crops globally. Despite this, various abiotic stresses, including drought, cause yield losses. We used transcriptome profiles to investigate the co-expression patterns of gene networks associated with drought stress tolerance. We identified three gene modules containing 3,567 genes highly associated with drought stress tolerance. Within these modules, we identified 13 hub genes based on intramodular significance, for further validation. The yellow module has five hub genes (Gh_A07G0563, Gh_D05G0221, Gh_A05G3716, Gh_D12G1438, and Gh_D05G0697), the brown module contains three hub genes belonging to the aldehyde dehydrogenase (ALDH) gene family (Gh_A06G1257, Gh_A06G1256, and Gh_D06G1578), and the pink module has five hub genes (Gh_A02G1616, Gh_D12G2599, Gh_D07G2232, Gh_A02G0527, and Gh_D07G0629). Based on RT-qPCR results, the Gh_A06G1257 gene has the highest expression under drought stress in different plant tissues and it might be the true candidate gene linked to drought stress tolerance in cotton. Silencing of Gh_A06G1257 in cotton leaves conferred significant sensitivity in response to drought stress treatments. Overexpression of Gh_A06G1257 in Arabidopsis also confirms its role in drought stress tolerance. L-valine, Glutaric acid, L-proline, L-Glutamic acid, and L-Tryptophan were found to be the most significant metabolites playing roles in drought stress tolerance. These findings add significantly to existing knowledge of drought stress tolerance mechanisms in cotton.

4.
Photosynth Res ; 150(1-3): 239-250, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34669149

RESUMO

Domestication involves dramatic phenotypic and physiological diversifications due to successive selection by breeders toward high yield and quality. Although photosynthetic nitrogen use efficiency (PNUE) is a major trait for understanding leaf nitrogen economy, it is unclear whether PNUE of cotton has been improved under domestication. Here, we investigated the effect of domestication on nitrogen allocation to photosynthetic machinery and PNUE in 25 wild and 37 domesticated cotton genotypes. The results showed that domesticated genotypes had higher nitrogen content per mass (Nm), net photosynthesis under saturated light (Asat), and PNUE but similar nitrogen content per area (Na) compared with wild genotypes. As expected, in both genotypes, PNUE was positively related to Asat but negatively correlated with Na. However, the relative contribution of Asat to PNUE was greater than the contribution from Na. Domesticated genotypes had higher nitrogen allocation to light-harvesting (NL, nitrogen in light-harvesting chlorophyll-protein complex), to bioenergetics (Nb, total nitrogen of cytochrome f, ferredoxin NADP reductase, and the coupling factor), and to Rubisco (Nr) than wild genotypes; however, the two genotype groups did not differ in PNUEp, the ratio of Asat to Np (itself the sum of NL, Nb, and Nr). Our results suggest that more nitrogen allocation to photosynthetic machinery has boosted Asat under cotton domestication. Improving the efficiency of nitrogen use in photosynthetic machinery might be future aim to enhance Asat of cotton.

5.
Front Plant Sci ; 12: 658755, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34447398

RESUMO

The acyl-coenzyme A oxidase 3 (ACX3) gene involved in the ß-oxidation pathway plays a critical role in plant growth and development as well as stress response. Earlier on, studies focused primarily on the role of ß-oxidation limited to fatty acid breakdown. However, ACX3 peroxisomal ß-oxidation pathways result in a downstream cascade of events that act as a transduction of biochemical and physiological responses to stress. A role that is yet to be studied extensively. In this study, we identified 20, 18, 22, 23, 20, 11, and 9 proteins in Gossypium hirsutum, G. barbadense, G. tomentosum, G. mustelinum, G. darwinii, G. arboretum, and G. raimondii genomes, respectively. The tetraploid cotton genome had protein ranging between 18 and 22, while diploids had between 9 and 11. After analyzing the gene family evolution or selection pressure, we found that this gene family undergoes purely segmental duplication both in diploids and tetraploids. W-Box (WRKY-binding site), ABRE, CAAT-Box, TATA-box, MYB, MBS, LTR, TGACG, and CGTCA-motif are abiotic stress cis-regulatory elements identified in this gene family. All these are the binding sites for abiotic stress transcription factors, indicating that this gene is essential. Genes found in G. hirsutum showed a clear response to drought and salinity stress, with higher expression under drought and salt stress, particularly in the leaf and root, according to expression analysis. We selected Gh_DO1GO186, one of the highly expressed genes, for functional characterization. We functionally characterized the GhACX3 gene through overexpression and virus-induced gene silencing (VIGS). Overexpression of this gene enhanced tolerance under stress, which was exhibited by the germination assay. The overexpressed seed growth rate was faster relative to control under drought and salt stress conditions. The survival rate was also higher in overexpressed plants relative to control plants under stress. In contrast, the silencing of the GhACX3 gene in cotton plants resulted in plants showing the stress susceptibility phenotype and reduced root length compared to control. Biochemical analysis also demonstrated that GhACX3-silenced plants experienced oxidative stress while the overexpressed plants did not. This study has revealed the importance of the ACX3 family during stress tolerance and can breed stress-resilient cultivar.

6.
J Exp Bot ; 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34153103

RESUMO

Mesophyll conductance (gm) is a crucial leaf trait contributing to photosynthetic rate (AN). Plant domestication typically leads to an enhancement of AN that is often associated with profoundly anatomical modifications but it is unclear which of these structural alterations influence gm. We analyzed the implication of domestication on leaf anatomy and its effect on gm in 26 wild and 31 domesticated cotton genotypes (Gossypium sp.) grown under field conditions. We found that domesticated genotypes had higher AN but similar gm to wild genotypes. Consistent with this, domestication did not translate into significant differences in the fraction of mesophyll occupied by intercellular airspaces (fias) or mesophyll and chloroplast surface area exposed to intercellular airspace (Sm/S and Sc/S, respectively). However, leaves of domesticated genotypes were significantly thicker, with larger but fewer mesophyll cells with thinner cell walls. Moreover, domesticated genotypes had higher cell wall conductance (gcw) but smaller cytoplasmic conductance (gcyt) than wild genotypes. It appears that domestication in cotton has not generally led to significant improvement in gm, in part because their thinner mesophyll cell walls (increasing gcw) compensate for their lower gcyt, itself due to larger distances between plasmalemma and chloroplast envelopes.

7.
Plant Physiol Biochem ; 166: 361-375, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34153881

RESUMO

Cotton encounters long-term drought stress problems resulting in major yield losses. Transcription factors (TFs) plays an important role in response to biotic and abiotic stresses. The coexpression patterns of gene networks associated with drought stress tolerance were investigated using transcriptome profiles. Applying a weighted gene coexpression network analysis, we discovered a salmon module with 144 genes strongly linked to drought stress tolerance. Based on coexpression and RT-qPCR analysis GH_D01G0514 was selected as the candidate gene, as it was also identified as a hub gene in both roots and leaves with a consistent expression in response to drought stress in both tissues. For validation of GH_D01G0514, Virus Induced Gene Silencing was performed and VIGS plants showed significantly higher excised leaf water loss and ion leakage, while lower relative water and chlorophyll contents as compared to WT (Wild type) and positive control plants. Furthermore, the WT and positive control seedlings showed higher CAT and SOD activities, and lower activities of hydrogen peroxide and MDA enzymes as compared to the VIGS plants. Gh_D01G0514 (GhNAC072) was localized in the nucleus and cytoplasm. Y2H assay demonstrates that Gh_D01G0514 has a potential of auto activation. It was observed that the Gh_D01G0514 was highly upregulated in both tissues based on RNA Seq and RT-qPCR analysis. Thus, we inferred that, this candidate gene might be responsible for drought stress tolerance in cotton. This finding adds significantly to the existing knowledge of drought stress tolerance in cotton and deep molecular analysis are required to understand the molecular mechanisms underlying drought stress tolerance in cotton.


Assuntos
Secas , Fatores de Transcrição , Regulação da Expressão Gênica de Plantas , Gossypium/genética , Gossypium/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Fatores de Transcrição/genética
8.
PLoS One ; 16(3): e0247593, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33770112

RESUMO

Segregation distortion (SD) is a genetic mechanism commonly found in segregating or stable populations. The principle behind this puzzles many researchers. The F2 generation developed from wild Gossypium darwinii and G. hirsutum CCRI12 species was used to investigate the possible transcription factors within the segregation distortion regions (SDRs). The 384 out of 2763 markers were distorted in 29 SDRs on 18 chromosomes. Good collinearity was observed among genetic and physical maps of G. hirsutum and G. barbadense syntenic blocks. Total 568 genes were identified from SDRs of 18 chromosomes. Out of these genes, 128 belonged to three top-ranked salt-tolerant gene families. The DUF597 contained 8 uncharacterized genes linked to Pkinase (PF00069) gene family in the phylogenetic tree, while 15 uncharacterized genes clustered with the zinc finger gene family. Two hundred thirty four miRNAs targeted numerous genes, including ghr-miR156, ghr-miR399 and ghr-miR482, while others targeted top-ranked stress-responsive transcription factors. Moreover, these genes were involved in the regulation of numerous stress-responsive cis-regulatory elements. The RNA sequence data of fifteen upregulated genes were verified through the RT-qPCR. The expression profiles of two highly upregulated genes (Gh_D01G2015 and Gh_A01G1773) in salt-tolerant G. darwinii showed antagonistic expression in G. hirsutum. The results indicated that salt-tolerant genes have been possibly transferred from the wild G. darwinii species. A detailed functional analysis of these genes can be carried out which might be helpful in the future for gene cloning, transformation, gene editing and the development of salt-resistant cotton varieties.


Assuntos
Alelos , Mapeamento Cromossômico/métodos , Segregação de Cromossomos/genética , Frequência do Gene , Genes de Plantas , Gossypium/genética , Tolerância ao Sal/genética , Sequência de Bases/genética , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , Filogenia , Proteínas de Plantas/genética , RNA de Plantas/genética , Sintenia/genética , Fatores de Transcrição/genética , Transcriptoma , Regulação para Cima/genética
9.
Front Plant Sci ; 12: 759312, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34992618

RESUMO

Drought and low-temperature stresses are the most prominent abiotic stresses affecting cotton. Wild cotton being exposed to harsh environments has more potential to cope with both biotic and abiotic stresses. Exploiting wild cotton material to induce resistant germplasm would be of greater interest. The candidate gene was identified in the BC2F2 population among Gossypium tomentosum and Gossypium hirsutum as wild male donor parent noted for its drought tolerance and the recurrent parent and a high yielding but drought susceptible species by genotyping by sequencing (GBS) mapping. Golden2-like (GLK) gene, which belongs to the GARP family, is a kind of plant-specific transcription factor (TF) that was silenced by virus-induced gene silencing (VIGS). Silencing of GhGLK1 in cotton results in more damage to plants under drought and cold stress as compared with wild type (WT). The overexpression of GhGLK1 in Arabidopsis thaliana showed that the overexpressing plants showed more adaptability than the WT after drought and cold treatments. The results of trypan blue and 3,3'-diaminobenzidine (DAB) staining showed that after drought and cold treatment, the leaf damage in GhGLK1 overexpressed plants was less as compared with the WT, and the ion permeability was also lower. This study suggested that the GhGLK1 gene may be involved in the regulation of drought and cold stress response in cotton. Our current research findings add significantly to the existing knowledge of cold and drought stress tolerance in cotton.

10.
BMC Plant Biol ; 20(1): 518, 2020 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-33183239

RESUMO

BACKGROUND: Wild species of cotton are excellent resistance to abiotic stress. Diploid D-genome cotton showed abundant phenotypic diversity and was the putative donor species of allotetraploid cotton which produce the largest textile natural fiber. RESULTS: A total of 41,053 genes were expressed in all samples by mapping RNA-seq Illumina reads of G. thurberi (D1), G. klotzschianum (D3-k), G. raimondii (D5) and G. trilobum (D8) to reference genome. The numbers of differently expressed genes (DEGs) were significantly higher under cold stress than salt stress. However, 34.1% DEGs under salt stress were overlapped with cold stress in four species. Notably, a potential shared network (cold and salt response, including 16 genes) was mined out by gene co-expression analysis. A total of 47,180-55,548 unique genes were identified in four diploid species by De novo assembly. Furthermore, 163, 344, 330, and 161 positively selected genes (PSGs) were detected in thurberi, G. klotzschianum, G. raimondii and G. trilobum by evolutionary analysis, respectively, and 9.5-17% PSGs of four species were DEGs in corresponding species under cold or salt stress. What's more, most of PSGs were enriched GO term related to response to stimulation. G. klotzschianum showed the best tolerance under both cold and salt stress. Interestingly, we found that a RALF-like protein coding gene not only is PSGs of G. klotzschianum, but also belongs to the potential shared network. CONCLUSION: Our study provided new evidence that gene expression variations of evolution by natural selection were essential drivers of the morphological variations related to environmental adaptation during evolution. Additionally, there exist shared regulated networks under cold and salt stress, such as Ca2+ signal transduction and oxidation-reduction mechanisms. Our work establishes a transcriptomic selection mechanism for altering gene expression of the four diploid D-genome cotton and provides available gene resource underlying multi-abiotic resistant cotton breeding strategy.


Assuntos
Resposta ao Choque Frio/genética , Diploide , Evolução Molecular , Gossypium/genética , Gossypium/fisiologia , Estresse Salino/genética , Transcriptoma/genética , Resposta ao Choque Frio/fisiologia , Regulação da Expressão Gênica de Plantas , Variação Genética , Genoma de Planta , Genótipo , Filogenia , Estresse Salino/fisiologia
11.
Technol Cancer Res Treat ; 19: 1533033820920967, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32356485

RESUMO

BACKGROUND: In recent studies, microRNAs have been demonstrated as stable detectable biomarkers in blood for cancer. In addition, computer-aided biomarker discovery has now become an attractive paradigm for precision diagnosis. METHODS: In this study, we identified and evaluated miR-139-3p as a biomarker for screening of esophageal squamous cell carcinoma using the Cancer Genome Atlas and Gene Expression Omnibus database analyses. We identified possible miR-139-3p target genes through the predicted database and esophageal squamous cell carcinoma upregulated genes from the Cancer Genome Atlas and Gene. Bioinformatics analysis was performed to determine key miR-139-3p targets and pathways associated with esophageal carcinoma. Finally, the expression and expected significance of hub genes were evaluated via the Genotype-Tissue Expression project. RESULTS: MiR-139-3p was significantly downregulated in patients with esophageal squamous cell carcinoma/esophageal carcinoma. In GSE 122497, the area under the curve-receiver operating characteristic value, sensitivity, and specificity for serum miR-139-3p were 0.754, 67.49%, and 80.00%, respectively. The pattern specification process, skeletal system development, and regionalization process were the most enriched interactions in esophageal carcinoma. In addition, Epstein-Barr virus infection, human T-cell leukemia virus 1 infection, and human cytomegalovirus infection were identified as crucial pathways. Six hub genes (CD1A, FCGR2A, ANPEP, CD1B, membrane metalloendopeptidase, and TWIST1) were found, and FCGR2A and membrane metalloendopeptidase were further confirmed by genotype-tissue expression. High expression of membrane metalloendopeptidase correlated with a better overall survival but not with disease-free survival of patients with esophageal carcinoma. CONCLUSIONS: MiR-139-3p was identified as a candidate biomarker for predicting esophageal squamous cell carcinoma based on network analysis. MiR-139-3p acted as a tumor suppressor by targeting membrane metalloendopeptidase in esophageal carcinoma, and low expression of membrane metalloendopeptidase may indicate a better prognosis of patients with esophageal carcinoma.


Assuntos
Neoplasias Esofágicas/sangue , Carcinoma de Células Escamosas do Esôfago/sangue , MicroRNAs/sangue , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Biologia Computacional/métodos , Bases de Dados Genéticas , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/patologia , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes , Humanos , MicroRNAs/genética , Prognóstico , Mapas de Interação de Proteínas , Taxa de Sobrevida
12.
Environ Sci Pollut Res Int ; 27(23): 29055-29067, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32424757

RESUMO

Since the "5.12" Wenchuan earthquake in 2008, frequent geologic hazards along the Longmenshan fault zone have had significant impacts on the socioeconomic conditions in the earthquake-stricken areas. Therefore, from the perspective of earthquake-induced hazards, this paper focuses on analyzing the change rules of disaster resilience under the spatial and temporal aggregation effects of earthquake-induced hazards, and this analysis provides an important basis for understanding the developmental characteristics of earthquake-induced hazards and disaster prevention, and mitigation after earthquakes. This paper takes Wenchuan County as an example. By collecting the 2008-2018 landslide geological hazards data, the global autocorrelation coefficient and local autocorrelation coefficient are adopted to analyze the temporal trends and spatial patterns of earthquake-induced hazards. At the same time, from the socioeconomic perspective, two disaster resilience indexes, the compatibility coefficient of industrial and employment structure and per capita GDP growth rate, were constructed to analyze the disaster resilience under the spatial and temporal aggregation effect of landslide geological hazards. The results show that, on the temporal trend, the temporal aggregation effect of earthquake-induced hazards has periodically decayed with time; in the spatial distribution, the spatial clustering effect as a whole increases first and then decreases, and the scope of the aggregation effect tends to narrow spatially. Disaster resilience (Hxy and RGDP) showed a trend of increasing first and then decreasing, and could not recover to the level before the earthquake in 2017, indicating that Wenchuan County was greatly affected by earthquake-induced hazards in the post-earthquake reconstruction process.


Assuntos
Desastres , Terremotos , Deslizamentos de Terra , China , Emprego
13.
BMC Genomics ; 21(1): 15, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31906862

RESUMO

BACKGROUND: Cotton grows in altering environments that are often unfavorable or stressful for its growth and development. Consequently, the plant must cope with abiotic stresses such as soil salinity, drought, and excessive temperatures. Alkali-salt stress response remains a cumbersome biological process and is regulated via a multifaceted transcriptional regulatory network in cotton. RESULTS: To discover the molecular mechanisms of alkali-salt stress response in cotton, a comprehensive transcriptome analysis was carried out after alkali-salt stress treatment in three accessions of Gossypium hirsutum with contrasting phenotype. Expression level analysis proved that alkali-salt stress response presented significant stage-specific and tissue-specific. GO enrichment analysis typically suggested that signal transduction process involved in salt-alkali stress response at SS3 and SS12 stages in leaf; carbohydrate metabolic process and oxidation-reduction process involved in SS48 stages in leaf; the oxidation-reduction process involved at all three phases in the root. The Co-expression analysis suggested a potential GhSOS3/GhCBL10-SOS2 network was involved in salt-alkali stress response. Furthermore, Salt-alkali sensitivity was increased in GhSOS3 and GhCBL10 Virus-induced Gene Silencing (VIGS) plants. CONCLUSION: The findings may facilitate to elucidate the underlying mechanisms of alkali-salt stress response and provide an available resource to scrutinize the role of candidate genes and signaling pathway governing alkali-salt stress response.


Assuntos
Redes Reguladoras de Genes , Gossypium/genética , Estresse Salino , Tolerância ao Sal/genética , Estresse Fisiológico/genética , Álcalis/química , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Gossypium/anatomia & histologia , Gossypium/classificação , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Interferência de RNA , Especificidade da Espécie
14.
PeerJ ; 8: e8344, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31915591

RESUMO

The activity of genome-specific repetitive sequences is the main cause of genome variation between Gossypium A and D genomes. Through comparative analysis of the two genomes, we retrieved a repetitive element termed ICRd motif, which appears frequently in the diploid Gossypium raimondii (D5) genome but rarely in the diploid Gossypium arboreum (A2) genome. We further explored the existence of the ICRd motif in chromosomes of G. raimondii, G. arboreum, and two tetraploid (AADD) cotton species, Gossypium hirsutum and Gossypium barbadense, by fluorescence in situ hybridization (FISH), and observed that the ICRd motif exists in the D5 and D-subgenomes but not in the A2 and A-subgenomes. The ICRd motif comprises two components, a variable tandem repeat (TR) region and a conservative sequence (CS). The two constituents each have hundreds of repeats that evenly distribute across 13 chromosomes of the D5genome. The ICRd motif (and its repeats) was revealed as the common conservative region harbored by ancient Long Terminal Repeat Retrotransposons. Identification and investigation of the ICRd motif promotes the study of A and D genome differences, facilitates research on Gossypium genome evolution, and provides assistance to subgenome identification and genome assembling.

15.
Plant Biotechnol J ; 18(3): 814-828, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31479566

RESUMO

The diploid wild cotton species Gossypium australe possesses excellent traits including resistance to disease and delayed gland morphogenesis, and has been successfully used for distant breeding programmes to incorporate disease resistance traits into domesticated cotton. Here, we sequenced the G. australe genome by integrating PacBio, Illumina short read, BioNano (DLS) and Hi-C technologies, and acquired a high-quality reference genome with a contig N50 of 1.83 Mb and a scaffold N50 of 143.60 Mb. We found that 73.5% of the G. australe genome is composed of various repeat sequences, differing from those of G. arboreum (85.39%), G. hirsutum (69.86%) and G. barbadense (69.83%). The G. australe genome showed closer collinear relationships with the genome of G. arboreum than G. raimondii and has undergone less extensive genome reorganization than the G. arboreum genome. Selection signature and transcriptomics analyses implicated multiple genes in disease resistance responses, including GauCCD7 and GauCBP1, and experiments revealed induction of both genes by Verticillium dahliae and by the plant hormones strigolactone (GR24), salicylic acid (SA) and methyl jasmonate (MeJA). Experiments using a Verticillium-resistant domesticated G. barbadense cultivar confirmed that knockdown of the homologues of these genes caused a significant reduction in resistance against Verticillium dahliae. Moreover, knockdown of a newly identified gland-associated gene GauGRAS1 caused a glandless phenotype in partial tissues using G. australe. The G. australe genome represents a valuable resource for cotton research and distant relative breeding as well as for understanding the evolutionary history of crop genomes.


Assuntos
Resistência à Doença , Gossypium/genética , Austrália , Diploide , Regulação da Expressão Gênica de Plantas , Técnicas de Silenciamento de Genes , Morfogênese , Doenças das Plantas/genética
16.
Genomics ; 112(2): 1902-1915, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31733270

RESUMO

In this investigation, whole-genome identification and functional characterization of the cotton dehydrin genes was carried out. A total of 16, 7, and 7 dehydrin proteins were identified in G. hirsutum, G. arboreum and G. raimondii, respectively. Through RNA sequence data and RT-qPCR validation, Gh_A05G1554 (GhDHN_03) and Gh_D05G1729 (GhDHN_04) were highly upregulated, and knockdown of the two genes, significantly reduced the ability of the plants to tolerate the effects of osmotic and salt stress. The VIGS-plants recorded significantly higher concentration levels of oxidants, hydrogen peroxide (H2O2) and malondialdehyde (MDA), furthermore, the four stress responsive genes GhLEA2, Gh_D12G2017 (CDKF4), Gh_A07G0747 (GPCR) and a transcription factor, trihelix, Gh_A05G2067, were significantly downregulated in VIGS-plants, but upregulated in wild types under osmotic and salt stress condition. The result indicated that dehydrin proteins are vital for plants and can be exploited in developing a more osmotic and salt stress-resilient germplasm to boost and improve cotton production.


Assuntos
Gossypium/genética , Pressão Osmótica , Proteínas de Plantas/genética , Tolerância ao Sal , Gossypium/metabolismo , Estresse Oxidativo , Proteínas de Plantas/metabolismo
17.
Front Plant Sci ; 10: 1292, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31681384

RESUMO

We found 33, 17, and 20 Alba genes in Gossypium hirsutum, Gossypium arboretum, and Gossypium raimondii, respectively. The Alba protein lengths ranged from 62 to 312 aa, the molecular weight (MW) from 7.003 to 34.55 kDa, grand average hydropathy values of -1.012 to 0.609 and isoelectric (pI) values of -3 to 11. Moreover, miRNAs such as gra-miR8770 targeted four genes, gra-miR8752 and gra-miR8666 targeted three genes, and each and gra-miR8657 a, b, c, d, e targeted 10 genes each, while the rests targeted 1 to 2 genes each. Similarly, various cis-regulatory elements were detected with significant roles in enhancing abiotic stress tolerance, such as CBFHV (RYCGAC) with a role in cold stress acclimation among others. Two genes, Gh_D01G0884 and Gh_D01G0922, were found to be highly induced under water deficit and salt stress conditions. Through virus-induced gene silencing (VIGS), the VIGS cotton plants were found to be highly susceptible to both water deficit and salt stresses; the VIGS plants exhibited a significant reduction in root growth, low cell membrane stability (CMS), saturated leaf weight (SLW), chlorophyll content levels, and higher excised leaf water loss (ELWL). Furthermore, the stress-responsive genes and ROS scavenging enzymes were significantly reduced in the VIGS plants compared to either the wild type (WT) and or the positively controlled plants. The VIGS plants registered higher concentration levels of hydrogen peroxide and malondialdehyde, with significantly lower levels of the various antioxidants evaluated an indication that the VIGS plants were highly affected by salt and drought stresses. This result provides a key foundation for future exploration of the Alba proteins in relation to abiotic stress.

18.
AoB Plants ; 11(6): plz045, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31777648

RESUMO

Low temperature is one of the key environmental stresses that impair plant growth and significantly restricts the productivity and spatial distribution of crop plants. Gossypium thurberi, a wild diploid cotton species, has adapted to a wide range of temperatures and exhibits a better tolerance to chilling stress. Here, we compared phenotypes and physiochemical changes in G. thurberi under cold stress and found this species indeed showed better cold tolerance. Therefore, to understand the molecular mechanisms of the cold tolerance in G. thurberi, we compared transcription changes in leaves of G. thurberi under cold stress by high-throughput transcriptome sequencing. In total, 35 617 unigenes were identified in the whole-genome transcription profile, and 4226 differentially expressed genes (DEGs) were discovered in the leaves upon cold treatment. Gene Ontology (GO) classification analyses showed that the majority of DEGs belonged to categories of signal transduction, transcription factors (TFs) and carbohydrate transport and metabolism. The expression of several cold-responsive genes such as ICE1, CBF4, RAP2-7 and abscisic acid (ABA) biosynthesis genes involved in different signalling pathways were induced after G. thurberi seedlings were exposed to cold stress. Furthermore, cold sensitivity was increased in CBF4 and ICE2 virus-induced gene silencing (VIGS) plants, and high level of malondialdehyde (MDA) showed that the CBF4 and ICE2 silenced plants were under oxidative stress compared to their wild types, which relatively had higher levels of antioxidant enzyme activity, as evident by high levels of proline and superoxide dismutase (SOD) content. In conclusion, our findings reveal a new regulatory network of cold stress response in G. thurberi and broaden our understanding of the cold tolerance mechanism in cotton, which might accelerate functional genomics studies and genetic improvement for cold stress tolerance in cultivated cotton.

19.
Int J Mol Sci ; 20(19)2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31597268

RESUMO

Nitrogen is a key macronutrient needed by plants to boost their production, but the development of cotton genotypes through conventional approaches has hit a bottleneck due to the narrow genetic base of the elite cotton cultivars, due to intensive selection and inbreeding. Based on our previous research, in which the BC2F2 generations developed from two upland cotton genotypes, an abiotic stress-tolerant genotype, G. tomentosum (donor parent) and a highly-susceptible, and a highly-susceptible, but very productive, G. hirsutum (recurrent parent), were profiled under drought stress conditions. The phenotypic and the genotypic data generated through genotyping by sequencing (GBS) were integrated to map drought-tolerant quantitative trait loci (QTLs). Within the stable QTLs region for the various drought tolerance traits, a nodule-inception-like protein (NLP) gene was identified. We performed a phylogenetic analysis of the NLP proteins, mapped their chromosomal positions, intron-exon structures and conducted ds/dn analysis, which showed that most NLP genes underwent negative or purifying selection. Moreover, the functions of one of the highly upregulated genes, Gh_A05G3286 (Gh NLP5), were evaluated using the virus gene silencing (VIGS) mechanism. A total of 226 proteins encoded by the NLP genes were identified, with 105, 61, and 60 in Gossypium hirsutum, G. raimondii, and G. arboreum, respectively. Comprehensive Insilico analysis revealed that the proteins encoded by the NLP genes had varying molecular weights, protein lengths, isoelectric points (pI), and grand hydropathy values (GRAVY). The GRAVY values ranged from a negative one to zero, showing that proteins were hydrophilic. Moreover, various cis-regulatory elements that are the binding sites for stress-associated transcription factors were found in the promoters of various NLP genes. In addition, many miRNAs were predicted to target NLP genes, notably miR167a, miR167b, miR160, and miR167 that were previously shown to target five NAC genes, including NAC1 and CUC1, under N-limited conditions. The real-time quantitative polymerase chain reaction (RT-qPCR) analysis, revealed that five genes, Gh_D02G2018, Gh_A12G0439, Gh_A03G0493, Gh_A03G1178, and Gh_A05G3286 were significantly upregulated and perhaps could be the key NLP genes regulating plant response under N-limited conditions. Furthermore, the knockdown of the Gh_A05G3286 (GhNLP5) gene by virus-induced silencing (VIGS) significantly reduced the ability of these plants to the knockdown of the Gh_A05G3286 (GhNLP5) gene by virus-induced gene silencing (VIGS) significantly reduced the ability of the VIGS-plants to tolerate N-limited conditions compared to the wild types (WT). The VIGS-plants registered lower chlorophyll content, fresh shoot biomass, and fresh root biomass, addition to higher levels of malondialdehyde (MDA) and significantly reduced levels of proline, and superoxide dismutase (SOD) compared to the WT under N-limited conditions. Subsequently, the expression levels of the Nitrogen-stress responsive genes, GhTap46, GhRPL18A, and GhKLU were shown to be significantly downregulated in VIGS-plants compared to their WT under N-limited conditions. The downregulation of the nitrogen-stress responsive genes provided evidence that the silenced gene had an integral role in enhancing cotton plant tolerance to N-limited conditions.


Assuntos
Adaptação Biológica , Mapeamento Cromossômico , Regulação da Expressão Gênica de Plantas , Gossypium/genética , Gossypium/metabolismo , Nitrogênio/deficiência , Proteínas de Plantas/genética , Adaptação Biológica/genética , Perfilação da Expressão Gênica , Inativação Gênica , Fenótipo , Filogenia , Desenvolvimento Vegetal/genética , Transporte Proteico , Locos de Características Quantitativas , Análise de Sequência de DNA , Estresse Fisiológico
20.
Plant Physiol Biochem ; 144: 166-177, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31568959

RESUMO

Drought, salinity and cold stresses have a major impact on cotton production, thus identification and utilization of plant genes vital for plant improvement Whole-genome identification and functional characterizations of the IQ67-domain (IQD) protein family was carried out in which 148, 77, and 79 IQD genes were identified in Gossypium hirsutum, G. raimondii, and G. arboreum. The entire IQD proteins had varied physiochemical properties, however; their grand hydropathy values were negative, which demonstrated that the proteins were hydrophilic, a property common among the proteins encoded by various stresses responsive genes, such as the late embryogenesis abundant (LEA) proteins. The IQD proteins were predicted to be majorly sublocalized in the nucleus; moreover, various cis-regulatory elements with higher role in enhancing abiotic stress tolerance were detected. RNA-seq and RT-qPCR analysis revealed two key genes, Gh_D06G0014 and Gh_A09G1608 with significantly higher upregulation across the various tissues under drought, salt and cold stress. Knockdown of the two genes negatively affected the ability of G. hirsutum to tolerate the effects of the three stress factors, being all the antioxidant assayed were significantly low concentrations compared to the oxidizing enzymes in VIGS plants under stress, furthermore, morphological and physiological traits were all negatively affected in VIGS plants. Expression levels of GhLEA2, GhCDK_F4, GPCR (TOM1) and Gh_A05G2067 (TH), the stress responsive genes were all downregulated in the VIGS plants, but significantly upregulated in WT and positively controlled plants. The results demonstrated that the IQD genes could be responsible for enhancing drought, salt and cold stress tolerance in cotton.


Assuntos
Gossypium/metabolismo , Gossypium/fisiologia , Secas , Regulação da Expressão Gênica de Plantas , Genoma de Planta/genética , Genoma de Planta/fisiologia , Gossypium/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/fisiologia
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