Cotton yields are greatly reduced under high salinity stress conditions, although cotton is considered a moderately salt-tolerant crop. Understanding at the molecular level how cotton responds to ...salt stress will help in developing salt tolerant varieties. Here, we combined physiological analysis with isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomics of seedling leaves of 2 genotypes differing in salinity tolerance to 200 mM (18.3 dS/m) NaCl stress. Salt stress produced significant stress symptoms in the sensitive genotype Nan Dan Ba Di Da Hua (N), including lower relative water and chlorophyll contents and higher relative electrolyte leakage and Na
/K
ratio in leaf samples, compared with those in the tolerant genotype Earlistaple 7 (Z). A total of 58 differentially abundant salt-responsive proteins were identified. Asp-Glu-Ala-Asp (DEAD)-box ATP-dependent RNA helicase 3 and protochlorophyllide reductase were markedly suppressed after salt treatment, whereas the phosphate-related differentially abundant proteins (DAPs) phosphoethanolamine N-methyltransferase 1 and 14-3-3-like protein E were induced, and all these proteins may play significant roles in salt stress. Twenty-nine salt-responsive proteins were also genotype specific, and 62.1 and 27.6% of these were related to chloroplast and defense responses, respectively. Based on the
protein interaction database, orthologs of 25 proteins showed interactions in
, and among these, a calmodulin protein was predicted to have 212 functional partners. In addition, the Golgi apparatus and calcium may be important for salt secretion in cotton. Through integrative proteome and transcriptome analysis, 16 DAPs were matched to differentially expressed genes and verified using qRT-PCR. On the basis of these findings, we proposed that some proteins related to chloroplast, ATP, ribosomal, and phosphate metabolism as well as to the Golgi apparatus and calcium may play key roles in the short-term salt stress response of cotton seedling leaves.
Root systems are critical for plant growth and development. The Casparian strip in root systems is involved in stress resistance and maintaining homeostasis. Casparian strip membrane domain proteins ...(CASPs) are responsible for the formation of Casparian strips.
To investigate the function of CASPs in cotton, we identified and characterized 48, 54, 91 and 94 CASPs from Gossypium arboreum, Gossypium raimondii, Gossypium barbadense and Gossypium hirsutum, respectively, at the genome-wide level. However, only 29 common homologous CASP genes were detected in the four Gossypium species. A collinearity analysis revealed that whole genome duplication (WGD) was the primary reason for the expansion of the genes of the CASP family in the four cotton species. However, dispersed duplication could also contribute to the expansion of the GaCASPs gene family in the ancestors of G. arboreum. Phylogenetic analysis was used to cluster a total of 85 CASP genes from G. arboreum and Arabidopsis into six distinct groups, while the genetic structure and motifs of CASPs were conserved in the same group. Most GaCASPs were expressed in diverse tissues, with the exception of that five GaCASPs (Ga08G0113, Ga08G0114, Ga08G0116, Ga08G0117 and Ga08G0118) that were highly expressed in root tissues. Analyses of the tissue and subcellular localization suggested that GaCASP27 genes (Ga08G0117) are membrane protein genes located in the root. In the GaCASP27 silenced plants and the Arabidopsis mutants, the lateral root number significantly increased. Furthermore, GaMYB36, which is related to root development was found to regulate lateral root growth by targeting GaCASP27.
This study provides a fundamental understanding of the CASP gene family in cotton and demonstrates the regulatory role of GaCASP27 on lateral root growth and development.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Lycopene is a member of carotenoids that exhibits strong antioxidant activity. In this study, on the basis of screening suitable strain combination ATCC 14271(+) and ATCC 14272(−) and establishing ...the optimal inoculation proportion of mated culture (1/2, +/−, w/w) for carotenoid production, the efficiency of compounds, mainly tertiary amines, on enhancing the lycopene content of Blakeslea trispora was systematically assessed. Of these compounds, tripropylamine showed the best enhancing effect, and then sequentially followed by triethylamine, tributylamine, trimethylamine, diisopropylamine, and isopropylamine. After treated with 1.8 g/L tripropylamine for two days, the lycopene proportion was increased from 1.7% to 90.1%, while the β-carotene proportion was decreased from 91.1% to 6.4% of the total carotenoids. In this case, the lycopene and total carotenoid contents were increased to 83.2 and 92.4 mg/gDW, which were 315.8- and 5.9-fold of that of the untreated control, respectively; while the growth of mycelia was only decreased at 6.0 g/L tripropylamine. Gene expression analysis showed that all the tested genes, especially genes encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (hmgr) and isopentenyl pyrophosphate isomerase (ipi) in mevalonate pathway, as well as phytoene desaturase (carB) in carotenoid biosynthesis process were upregulated. Therefore, tripropylamine enhanced lycopene content of B. trispora by inhibiting the cyclase activity, and by upregulating the expression of genes associated with terpenoid biosynthesis. Besides, a possible association between the structure and the lycopene-enhancing capability of these compounds was also discussed.
•Tripropylamine exhibited the highest capability to enhance lycopene accumulation in Blakeslea trispora.•Tripropylamine is not only an inhibitor on cyclase activity but also as a stimulator on the total carotenogenesis.•Tripropylamine upregulated the transcript of genes associated with terpenoid biosynthesis pathway.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Millions of hectares of land are too saline to produce economically valuable crop yields. Salt tolerance in cotton is an imperative approach for improvement in response to ever-increasing soil ...salinization. Little is known about the genetic basis of salt tolerance in cotton at the seedling stage. To address this issue, a genome-wide association study (GWAS) was conducted on a core collection of a genetically diverse population of upland cotton (
L.) comprising of 419 accessions, representing various geographic origins, including China, USA, Pakistan, the former Soviet Union, Chad, Australia, Brazil, Mexico, Sudan, and Uganda. Phenotypic evaluation of 7 traits under control (0 mM) and treatment (150 mM) NaCl conditions depicted the presence of broad natural variation in the studied population. The association study was carried out with the efficient mixed-model association eXpedited software package. A total of 17,264 single-nucleotide polymorphisms (SNPs) associated with different salinity stress tolerance related traits were found. Twenty-three candidate SNPs related to salinity stress-related traits were selected. Final key SNPs were selected based on the r
value with nearby SNPs in a linkage disequilibrium (LD) block. Twenty putative candidate genes surrounding SNPs, A10_95330133 and D10_61258588, associated with leaf relative water content, RWC_150, and leaf fresh weight, FW_150, were identified, respectively. We further validated the expression patterns of twelve candidate genes with qRT-PCR, which revealed different expression levels in salt-tolerant and salt-sensitive genotypes. The results of our GWAS provide useful knowledge about the genetic control of salt tolerance at the seedling stage, which could assist in elucidating the genetic and molecular mechanisms of salinity stress tolerance in cotton plants.
To understand the mechanism of fiber development and pigmentation formation, the mRNAs of two cotton lines were sequenced: line Z128 (light brown fiber) was a selected mutant from line Z263 (dark ...brown fiber). The primary walls of the fiber cell in both Z263 and Z128 contain pigments; more pigments were laid in the lumen of the fiber cell in Z263 compared with that in Z128. However, Z263 contained less cellulose than Z128. A total of 71,895 unigenes were generated: 13,278 (20.26%) unigenes were defined as differentially expressed genes (DEGs) by comparing the library of Z128 with that of Z263; 5,345 (8.16%) unigenes were up-regulated and 7,933 (12.10%) unigenes were down-regulated. qRT-PCR and comparative transcriptional analysis demonstrated that the pigmentation formation in brown cotton fiber was possibly the consequence of an interaction between oxidized tannins and glycosylated anthocyanins. Furthermore, our results showed the pigmentation related genes not only regulated the fiber color but also influenced the fiber quality at the fiber elongation stage (10 DPA). The highly expressed flavonoid gene in the fiber elongation stage could be related to the fiber quality. DEGs analyses also revealed that transcript levels of some fiber development genes (Ca(2+)/CaM, reactive oxygen, ethylene and sucrose phosphate synthase) varied dramatically between these two cotton lines.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Camellia oleifera Abel. (C. oleifera), one of the four woody oil-producing plants in the world produces edible oils with high percentage of unsaturated fatty acid content in seeds. The mature C. ...oleifera seeds continue to undergo a series of physiological changes after harvest. To this end, the dynamic changes in nutrients, oil content, fatty acid composition, and endogenous hormone content in C. oleifera seeds under different natural drying times after harvest were investigated. The content of soluble sugar and soluble protein of C. oleifera seeds increased with the extension of natural drying, especially soluble sugar content increased nearly 2-fold at 30 d after post-harvest natural drying compared with that of the control group. The content of oil reached a peak (23.6%) at 30 d after post-harvest natural drying. During the post-harvest natural drying process, the relative content of palmitic acid and oleic acid increased, while the relative content of palmitic acid and linoleic acid decreased. Furthermore, the levels of unsaturated fatty acids (oleic acid, linoleic acid, linolenic acid, and arachidonic acid) increased significantly with increasing natural drying time. The overall trend of endogenous hormones SA, SL, and ACC concentrations increased with the post-harvest natural drying process. Furthermore, the concentration of SA, SL, and ACC were positively correlated with oil content. Altogether, post-harvest natural drying for 30 days significantly promoted the anabolism of oil and improved the quality of C. oleifera seeds. These findings provide a scientific basis for reasonable post-harvest treatment to improve Camellia oil yield.
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IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UL, UM, UPUK
Cottonseed is one of the most important raw materials for plant protein, oil and alternative biofuel for diesel engines. Understanding the complex genetic basis of cottonseed traits is requisite for ...achieving efficient genetic improvement of the traits. However, it is not yet clear about their genetic architecture in genomic level. GWAS has been an effective way to explore genetic basis of quantitative traits in human and many crops. This study aims to dissect genetic mechanism seven cottonseed traits by a GWAS for genetic improvement.
A genome-wide association study (GWAS) based on a full gene model with gene effects as fixed and gene-environment interaction as random, was conducted for protein, oil and 5 fatty acids using 316 accessions and ~ 390 K SNPs. Totally, 124 significant quantitative trait SNPs (QTSs), consisting of 16, 21, 87 for protein, oil and fatty acids (palmitic, linoleic, oleic, myristic, stearic), respectively, were identified and the broad-sense heritability was estimated from 71.62 to 93.43%; no QTS-environment interaction was detected for the protein, the palmitic and the oleic contents; the protein content was predominantly controlled by epistatic effects accounting for 65.18% of the total variation, but the oil content and the fatty acids except the palmitic were mainly determined by gene main effects and no epistasis was detected for the myristic and the stearic. Prediction of superior pure line and hybrid revealed the potential of the QTSs in the improvement of cottonseed traits, and the hybrid could achieve higher or lower genetic values compared with pure lines.
This study revealed complex genetic architecture of seven cottonseed traits at whole genome-wide by mixed linear model approach; the identified genetic variants and estimated genetic component effects of gene, gene-gene and gene-environment interaction provide cotton geneticist or breeders new knowledge on the genetic mechanism of the traits and the potential molecular breeding design strategy.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
is an important woody oil species in China. Its seed oil has been widely used as a cooking oil. Seed size is a crucial factor influencing the yield of seed oil. In this study, the horizontal ...diameter, vertical diameter and volume of
seeds showed a rapid growth tendency from 235 days after pollination (DAP) to 258 DAP but had a slight increase at seed maturity. During seed development, the expression of genes related to cell proliferation and expansion differ greatly. Auxin plays an important role in
seeds;
and
were significantly downregulated. Weighted gene co-expression network analysis screened 21 hub transcription factors for
seed horizontal diameter, vertical diameter and volume. Among them,
was significantly decreased and associated with all these three traits, while
and
were significantly increased and associated with horizontal diameter of
seeds. Additionally,
significantly decreased (2040-fold). Collectively, our data advances the knowledge of factors related to seed size and provides a theoretical basis for improving the yield of
seeds.
Cotton possesses certain physical features, including leaf and stem trichomes that help plants deter damage caused by insect pests, and to some extent, from abiotic factors as well. Among those ...features, trichomes (pubescence) hold a special place as a first line of defense and a managemental tool against sucking insect pests of cotton. Different insect pests of cotton (whiteflies, aphids, jassids, and boll weevil) severely damage the yield and quality of the crop. Likewise, whiteflies, aphids, jassids, and other insect pests are considered as potential carriers for cotton leaf curl viruses and other diseases. Genotyping by sequencing (GBS) study was conducted to understand and explore the genomic regions governing hairy (Pubescence) leaves and stem phenotypes. A total of 224 individuals developed from an intraspecific cross (densely haired cotton (Liaoyang duomao mian) × hairless cotton (Zong 128)) and characterized phenotypically for leaf and stem pubescence in different environments. Here we identify and report significant QTLs (quantitative trait loci) associated with leaf and stem pubescence, and the response of plant under pest (aphid) infestation. Further, we identified putative genes colocalized on chromosome A06 governing mechanism for trichome development and host-pest interaction. Our study provides a comprehensive insight into genetic architecture that can be employed to improve molecular marker-assisted breeding programs aimed at developing biotic (insect pests) resilient cotton cultivars.
Heterosis, a multigenic complex trait extrapolated as sum total of many phenotypic features, is widely utilized phenomenon in agricultural crops for about a century. It is mainly focused on ...establishing vigorous cultivars with the fact that its deployment in crops necessitates the perspective of genomic impressions on prior selection for metric traits. In spite of extensive investigations, the actual mysterious genetic basis of heterosis is yet to unravel. Contemporary crop breeding is aimed at enhanced crop production overcoming former achievements. Leading cotton improvement programs remained handicapped to attain significant accomplishments.
In mentioned context, a comprehensive project was designed involving a large collection of cotton accessions including 284 lines, 5 testers along with their respective F
hybrids derived from Line × Tester mating design were evaluated under 10 diverse environments. Heterosis, GCA and SCA were estimated from morphological and fiber quality traits by L × T analysis. For the exploration of elite marker alleles related to heterosis and to provide the material carrying such multiple alleles the mentioned three dependent variables along with trait phenotype values were executed for association study aided by microsatellites in mixed linear model based on population structure and linkage disequilibrium analysis. Highly significant 46 microsatellites were discovered in association with the fiber and yield related traits under study. It was observed that two-thirds of the highly significant associated microsatellites related to fiber quality were distributed on D sub-genome, including some with pleiotropic effect. Newly discovered 32 hQTLs related to fiber quality traits are one of prominent findings from current study. A set of 96 exclusively favorable alleles were discovered and C tester (A971Bt) posited a major contributor of these alleles primarily associated with fiber quality.
Hence, to uncover hidden facts lying within heterosis phenomenon, discovery of additional hQTLs is required to improve fibre quality. To grab prominent improvement in influenced fiber quality and yield traits, we suggest the A971 Bt cotton cultivar as fundamental element in advance breeding programs as a parent of choice.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK