Search Results (114)

The red plant phenotype of R1 cotton is a genetic marker produced by light-induced anthocyanin accumulation. GhPAP1D controls this trait. There are two 228 bp tandem repeats upstream of GhPAP1D in R1 cotton. In this study, GUS staining assays in transgenic Arabidopsis thaliana (L.) Heynh. demonstrated that tandem repeats in the GhPAP1D promoter-enhanced transcriptional activity. GhPAP1D is a homolog of A. thaliana AtPAP1. AtPAP1’s expression is regulated by photomorphogenesis-related transcription factors such as AtHY5 and AtBBXs. We identified the homologs of A. thaliana AtHY5, AtBBX21, and AtBBX24 in R1 cotton, designated as GhHY5, GhBBX21, and GhBBX24, respectively. Y1H assays confirmed that GhHY5, GhBBX21, and GhBBX24 each bound to the GhPAP1D promoter. Dual-luciferase reporter assays revealed that GhHY5 weakly activated the promoter activity of GhPAP1D. Heterologous expression assays in A. thaliana indicated that GhBBX21 promoted anthocyanin accumulation, whereas GhBBX24 had the opposite effect. Dual-luciferase assays showed GhBBX21 activated GhPAP1D transcription, while GhBBX24 repressed it. Further study indicated that GhHY5 did not enhance GhBBX21-mediated transcriptional activation of GhPAP1D but alleviates GhBBX24-induced repression. Together, our results demonstrate that GhBBX21 and GhBBX24 antagonistically regulate anthocyanin accumulation in R1 cotton under GhHY5 mediation, providing insights into light-responsive anthocyanin biosynthesis in cotton. Full article

Background: The GhA01EP1 gene in upland cotton encodes an epidermal-specific secreted glycoprotein, whose functional characterization remains unexplored beyond our initial discovery of its water deficit resistance association. Therefore, we further designed experiments to investigate the functional role of GhA01EP1. Methods: We sequenced and analyzed the transcriptomes of wild-type (Col-0) and GhA01EP1-transgenic Arabidopsis thaliana. The differences in morphological and biochemical indicators were examined. In addition, the proteins interacting with GhA01EP1 in Arabidopsis were screened using a glutathione-S-transferase pull-down assay. Results: The GhA01EP1-transgenic Arabidopsis plants flowered earlier, produced more branches, and had a higher seed yield than Col-0. Transcriptome analysis revealed that differentially expressed genes detected in the comparison of GhA01EP1-transgenic and Col-0 Arabidopsis under the water treatment (the control) were associated especially with circadian rhythm regulation, photoperiodic flowering reaction, hormone metabolism, glyoxalase I synthesis, antioxidant pathway, branching development, and carbon-nitrogen allocation. Under water-sufficient or water-deficient treatments, the glyoxalase I activity and lignin content of GhA01EP1-transgenic Arabidopsis were significantly higher. Under water deficit stress, the malondialdehyde and starch contents were significantly lower, while peroxidase activity and protein content were significantly higher than those of Col-0. Conclusions: GhA01EP1 synergistically improved the precocity, water deficit tolerance, and seed yield of GhA01EP1-transgenic Arabidopsis. Analysis of GhA01EP1 function provides a molecular basis for breeding improved cotton varieties. Full article

Cotton exhibits indeterminate growth potential at its apical meristem. In field cultivation, it is often necessary to restrict plant height by the foliar application of plant growth regulators or artificial topping. The genetic engineering of cotton architecture offers an efficient, environmentally friendly, and low-cost alternative to current field management. Our study aimed to improve the plant architecture of transgenic cotton by the suppression of GhSP, a key flowering repressor, via the RNA interference method. Sixteen independent transgenic lines were generated and classified as mildly, moderately, and severely suppressed, according to GhSP expression levels. Field evaluation revealed the dose-dependent effects of GhSP silencing on plant height. The mildly suppressed line GhSPi-#5 exhibited a semi-dwarf phenotype of approximately 70~100 cm in height. Negative phenotypes, including excessive dwarf plant architecture and inferior fiber quality and yield traits, were observed in severely GhSP-suppressed transgenic lines. Notably, the mild silencing of GhSP in GhSPi-#5 did not negatively affect leaf and flower organ growth, pollen fertility, major agronomic traits, or fiber quality compared with the wild type. These observations demonstrate the feasibility of manipulating the architecture of transgenic cotton via GhSP silencing. Full article

Verticillium wilt (VW), induced by the soil-borne fungus Verticillium dahliae, represents a significant threat to global cotton production. Phenylalanine ammonia-lyase (PAL) is an essential enzyme in lignin metabolism that helps plants defend themselves against pathogenic fungal. Nonetheless, its role in imparting resistance to V. dahliae in cotton required further investigation. This study identified the GhPAL9 (GH_D04G1247) as a crucial gene in cotton resistance to V. dahliae via RNA-seq analysis, demonstrating significant upregulation in the resistant variety Xinluzao84. Bioinformatics analysis revealed the conserved evolutionary relationship of GhPAL9 with PAL homologs across various species and highlighted stress-responsive cis-elements in its promoter region. The expression of GhPAL9 was rapidly activated in roots, stems, and leaves following infection with V. dahliae, peaking between 2 and 8 h post inoculation (hpi). Silencing GhPAL9 through virus-induced gene silencing (VIGS) technology intensified disease symptoms, elevated relative fungal biomass, and diminished lignin accumulation, thereby affirming its function in cotton resistance to V. dahliae. The overexpression of GhPAL9 in Arabidopsis improved resistance to V. dahliae, and the OE-GhPAL9 transgenic lines demonstrated reduced disease severity and diminished relative fungal biomass. The results gave us new information about how VW resistance at the molecular level, which established that GhPAL9 acted as a positive regulator to increase resistance to VW via lignin accumulation. Full article

ZDRF-8 is a transgenic maize event created via Agrobacterium-mediated transformation for insect resistance and glyphosate tolerance by expressing Cry1Ab, Cry2Ab, and G10evo-epsps. A Southern blot analysis suggested that it is a single-copy T-DNA insertion event. The flanking genomic sequences of the T-DNA insertion suggested that its T-DNA was inserted at the terminal region of the long arm of chromosome 7 without interrupting any known or predicted genes. Event-specific PCRs based on the flanking sequence were able to detect this event specifically. Laboratory bioassays and field trials of multiple generations demonstrated that ZDRF-8 is highly active against major corn pests in China, including Asian corn borers (ACB, Ostrinia furnacalis), cotton bollworms (CBW, Helicoverpa armigera), and oriental armyworm (OAW, Mythimna separata), and meanwhile confers glyphosate tolerance up to two times the recommended dose. The expression of the transgenes and the efficacy of insect resistance and glyphosate tolerance were stable over more than 10 generations. ZDRF-8 has been granted with a safety certificate in China, and its commercial release is expected in the coming years. Full article

The novel plant hormone strigolactones (SL) are involved significantly in plant growth and development. Its key members SMXL6, 7, 8 can modulate SL signal reception and response negatively and can regulate plant branching remarkably. There are relatively scarce studies of cotton SMXL gene family, and this study was carried out to clarify the role of GbSMXL8 in cotton fiber development. Phylogenetic analysis identified 48 cotton SMXL genes, which were divided into SMXL-I (SMXL 1, 2), SMXL-II (SMXL 3) and SMXL-III (SMXL6, 7, 8) groups. The results of the cis-element analysis indicated that the SMXL gene could respond to hormones and the environment to modulate cotton growth process. A candidate gene GbSMXL8 was screened out based on the expression difference in extreme varieties of Gossypium barbadense. Tissue-specific analysis indicated that GbSMXL8 was mainly expressed in roots, 20D, 25D, and 35D and was involved in SL signaling pathways. In vitro ovule culture experiments showed that exogenous SLs (GR24) could promote the fiber elongation of G. barbadense, and GbSMXL8 expression was increased after GR24 treatment, indicating that GbSMXL8 was specifically responsive to GR24 in regulating fiber growth. GbSMXL8 knockout resulted in creased length and number of epidermal hairs and the length of fiber, indicating the interference role of GbSMXL8 gene with the development of cotton fiber. The GbSMXL8 transgenic plant was detected with a higher chlorophyll content and photosynthetic rate than those of the control plant, producing a direct impact on plant growth, yield, and biomass accumulation. GbSMXL8 gene knockout could increase plant height, accelerate growth rate, and lengthen fiber length. Intervening GbSMXL8 may mediate cotton growth, plant type formation and fiber elongation. In conclusion, the present study uncovers the function of GbSMXL8-mediated SL signal in cotton, providing theoretical insight for future breeding of new cotton varieties. Full article

In our previous research, we found that CYP6CY3 not only participates in the detoxification metabolism of neonicotinoid insecticides in cotton aphid but also affects their growth and development. However, how does transgenic cotton expressing dsAgCYP6CY3 affect the growth and development of cotton aphid? In this study, we combined transcriptome and metabolome to analyze how to inhibit the growth and development of cotton aphid treated with transgenic cotton expressing dsAgCYP6CY3-P1 (TG cotton). The results suggested that a total of 509 differentially expressed genes (DEGs) were identified based on the DESeq method, and a total of 431 differential metabolites (DAMs) were discovered using UPLC-MS in the metabolic analysis. Additionally, multiple DEGs and DAMs of glycolytic and The tricarboxylic acid (TCA) cycle pathways were significantly down-regulated. Pyruvate carboxylase (PC), citrate synthase (CS), malate dehydrogenase (MDH) enzyme activities and pyruvate content were reduced in cotton aphid treated with TG cotton. In addition, TG cotton could significantly decrease the total sugar content from the body and honeydew in cotton aphid. The above results indicated that TG cotton inhibited glycolysis and the TCA cycle, and this inhibition is consistent with previous studies showing that cotton aphid fed on TG cotton showed significantly reduced body length and weight as well as delayed molting. These findings provide a new strategy for reducing the transmission of viruses by cotton aphid honeydew, preventing fungal growth, mitigating impacts on normal photosynthesis and improving cotton quality. Full article

Flowering in plants is pivotal for initiating and advancing reproductive processes, impacting regional adaptation and crop yield. Despite numerous cloned and identified flowering time genes, research in cotton remains sparse. This study identified GhSWEET42 as a key determinant of the flowering time in cotton, demonstrating that its heterologous expression in Arabidopsis accelerated flowering under LD conditions compared to WT. Transgenic plants exhibited upregulated expression of the flowering inducers AtFT, AtSOC1, AtGI, and AtFKF1, alongside downregulated expression of the repressors AtTSF, AtFLC, and AtRGL2, correlating with the earlier flowering phenotype. GhSWEET42 showed a constitutive expression pattern, with elevated levels in the leaves, petals, and flower buds, and was notably higher in early-maturing cotton varieties. Subcellular localization assays confirmed GhSWEET42’s presence on the cell membrane. Transcriptome analysis between WT and GhSWEET42-overexpressing Arabidopsis plants revealed 2393 differentially expressed genes (DEGs), spanning 221 biological processes, 93 molecular functions, and 37 cellular components according to Gene Ontology (GO) enrichment analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis categorized the DEGs into metabolism and environmental information processing. These findings enhance the understanding of GhSWEET42’s function and provide a foundation for elucidating the molecular mechanisms governing flowering time regulation in cotton. Full article

The aquatic ecotoxicity of three α-amino acid-derived polyamidoamines (PAAs) was studied using zebrafish embryos as a viable vertebrate model organism. The PAAs examined were water-soluble amphoteric polyelectrolytes with a primarily negative charge, which were efficient flame retardants for cotton. The fish embryo acute toxicity test performed with PAA water solutions using 1.5–500 mg L⁻¹ concentrations showed that toxicity did not statistically differ from the control. The survival rates were indeed >90%, even at the highest concentration; the hatching rates were >80%; and the numbers of morphological defects were comparable to those of the control. Tests using transgenic zebrafish lines indicated that the numbers of microscopic vascular and musculoskeletal defects were comparable to the control, with one random concentration showing doubled alterations. Sensory–motor tests in response to visual and tactile stimuli were also performed. In the presence of PAAs, embryos exposed to alternating light/dark cycles showed an insignificant mobility reduction during the dark phase. Touch-evoked response tests revealed a mild effect of PAAs on the neuromotor system at concentrations > 10 mg L⁻¹. The cystine/glycine copolymer at 100 mg L⁻¹ exhibited the greatest effect. Overall, the studied PAAs showed a minimal impact on aquatic systems and should be further considered as promising ecofriendly materials. Full article

The beet armyworm, Spodoptera exigua (Hübner), is a major pest of maize, cotton, soybean, and many other crops globally. Despite the widespread deployment of Bt transgenic maize for pest control worldwide, the efficacy of Bt lepidopteran-resistant transgenic maize in managing S. exigua remains rarely studied. In this study, we quantified the expression level of pyramided Cry1Ab and Vip3Aa toxins in Bt maize (event DBN3601T) and evaluated their control efficiency against S. exigua under both laboratory and field conditions. The enzyme-linked immunosorbent assay (ELISA) results showed that the expression levels of Cry1Ab and Vip3Aa proteins in DBN3601T maize tissues followed a decreasing order as follows: V5-leaf > V8-leaf > VT-tassel > R2-kernel > R1-silk. Diet-overlay assay results showed that the LC₅₀ values of Cry1Ab and Vip3Aa proteins against S. exigua larvae were 11.66 ng/cm² and 27.74 ng/cm², respectively, with corresponding GIC₅₀ values at 1.59 ng/cm² and 7.93 ng/cm². Bioassay using various tissues of the DBN3601T maize indicated that after 7 days of infestation, mortality rates of neonates and third-instar larvae ranged from 86% to 100% and 58% to 100%, respectively. Mortality was highest on V5 and V8 leaves, followed by R2-kernel, VT-tassel, and R1-silk. Field trials demonstrated that DBN3601T maize exhibited significantly lower larval density, damage rate, and leaf damage score compared to non-Bt maize. Field cage trial showed that the control efficacy of DBN3601T maize at the vegetative stage could reach 98%. These findings provide a theoretical basis for utilizing Bt transgenic maize to enhance the sustainable management of S. exigua in Asia. Full article

The WRKY gene family is ubiquitously distributed in plants, serving crucial functions in stress responses. Nevertheless, the structural organization and evolutionary dynamics of WRKY genes in cotton have not been fully elucidated. In this study, a total of 112, 119, 217, and 222 WRKY genes were identified in Gossypium arboreum, Gossypium raimondii, Gossypium hirsutum, and Gossypium barbadense, respectively. These 670 WRKY genes were categorized into seven distinct subgroups and unequally distributed across chromosomes. Examination of conserved motifs, domains, cis-acting elements, and gene architecture collectively highlighted the evolutionary conservation and divergence within the WRKY gene family in cotton. Analysis of synteny and collinearity further confirmed instances of expansion, duplication, and loss events among WRKY genes during cotton evolution. Furthermore, GhWRKY31 transgenic Arabidopsis exhibited heightened germination rates and longer root lengths under drought and salt stress. Silencing GhWRKY31 in cotton led to reduced levels of ABA, proline, POD, and SOD, along with downregulated expression of stress-responsive genes. Yeast one-hybrid and molecular docking assays confirmed the binding capacity of GhWRKY31 to the W box of GhABF1, GhDREB2, and GhRD29. The findings collectively offer a systematic and comprehensive insight into the evolutionary patterns of cotton WRKYs, proposing a suitable regulatory framework for developing cotton cultivars with enhanced resilience to drought and salinity stress. Full article

The structure and expression of exogenous genes in transgenic crops are critical for the target traits. R7569 has the same exogenous insertion structure as the transgenic insect-resistant cotton MON531 but with a deletion in the 3′ end of the cry1Ac gene and the terminator region. Thus, in the present study, transcription, expression, and insecticidal activity assays were conducted to determine the function of the truncated cry1Ac gene. R7569 has a truncated cry1Ac gene with a length of 2554 bp encoding 881 amino acids, and the transcription termination site was mainly concentrated downstream of the truncated position and extended 160–270 bp from the truncated position using rapid amplification of cDNA ends (RACE). The transcript levels of the cry1Ac gene in R7569 were significantly higher than those of MON531 implants, except for during the boll stage. The content of the Cry1Ac protein in R7569 was higher than that of MON531 in the cotton leaf in all three periods. The corrected mortality rates of R7569 and MON531 against bollworms were 93.09% and 88.83%, respectively. The LC₅₀ value of R7569 was 0.732 ng/g (dw), indicating a high level of resistance to bollworm. In this study, for the first time, we found a partial deletion of the target gene in commercially applied transgenic crops, and the partial deletion of the 3′ end of the cry1Ac gene retained a better transcription, expression level, and insecticidal activity, which can provide a specific case for the safety evaluation of transgenic crops. Full article

Verticillium wilt, caused by the pathogenic fungus Verticillium dahliae, has emerged as a severe threat to cotton globally. However, little is known about the genetic diversity of this pathogen in an infected single cotton plant. In this study, we isolated three new V. dahliae strains from the disease stems of Gossypium hirsutum from the cotton field in Western China and assessed their pathogenicity to the cotton cultivar Xinnongmian-1 and its two transgenic lines, as well as two laboratory strains, VD592 and VD991. These three new V. dahliae strains were identified using DNA barcodes of tryptophan synthase (TS), actin (ACT), elongation factor 1-α (EF), and glyceraldehyde-3-phosphate dehydrogenase (GPD). Moreover, the haplotype analysis revealed that the three new races had distinct haplotypes at the TS locus. Furthermore, the results of culture features and genetic diversity of ISSR (inter-simple sequence repeat) revealed that there were separate V. dahliae strains, which were strong defoliating pathotypes belonging to race 2 type, as determined by particular DNA marker recognition. The identified strains demonstrated varied levels of pathogenicity by leaf disc and entire plant inoculation methods. Conservatively, these strains showed some pathogenicity on cotton lines, but were less pathogenic than the reference strains. The findings revealed that several strong defoliating V. dahliae pathotypes coexist on the same cotton plant. It indicats the importance of regular monitoring as an early warning system, as well as the detection and reporting of virulent pathogen strains and their effects on crop response. Full article

The application of sound wave technology to different plant species has revealed that variations in the Hz, sound pressure intensity, treatment duration, and type of setup of the sound source significantly impact the plant performance. A study conducted on cotton plants treated with Plant Acoustic Frequency Technology (PAFT) highlighted improvements across various growth metrics. In particular, the treated samples showed increases in the height, size of the fourth expanded leaf from the final one, count of branches carrying bolls, quantity of bolls, and weight of individual bolls. Another study showed how the impact of a 4 kHz sound stimulus positively promoted plant drought tolerance. In other cases, such as in transgenic rice plants, GUS expression was upregulated at 250 Hz but downregulated at 50 Hz. In the same way, sound frequencies have been found to enhance the osmotic potential, with the highest observed in samples treated with frequencies of 0.5 and 0.8 kHz compared to the control. Furthermore, a sound treatment with a frequency of 0.4 kHz and a sound pressure level (SPL) of 106 dB significantly increased the paddy rice germination index, as evidenced by an increase in the stem height and relative fresh weight. This paper presents a complete, rationalized and updated review of the literature on the effects of sound waves on the physiology and growth parameters of sound-treated plants. Full article

Prior to the recent implementation of the Mpp51Aa2 pesticidal protein (ThryvOn), transgenic cotton cultivars have historically offered no control of the cotton fleahopper (Pseudatomocelis seriatus (Reuter)). To evaluate the feeding behavior of cotton fleahoppers on ThryvOn cotton, electropenetrography (EPG) using a Giga-8 DC instrument was used to monitor the probing activity of fourth- and fifth-instar cotton fleahopper nymphs on both ThryvOn and non-ThryvOn cotton squares. Nymphs were individually placed on an excised cotton square for 8 h of EPG recording, after which resulting waveforms were classified as non-probing, cell rupturing, or ingestion. Although there were significantly more cell rupturing events per insect on ThryvOn (mean ± SEM, 14.8 ± 1.7) than on non-ThryvOn squares (mean ± SEM, 10.3 ± 1.6), there was no difference attributable to ThryvOn in the average number of ingestion events per insect. However, the average duration of ingestion events was significantly shorter on squares with ThryvOn (mean ± SEM, 509 ± 148 s) than on squares without (mean ± SEM, 914 ± 135 s). This suggests that cotton fleahoppers continued to probe despite their inability to sustain ingestion. These results provide conclusive evidence that the Mpp51Aa2 pesticidal protein affects the feeding behavior of cotton fleahopper nymphs. Full article