Search Results (23)

Background: High-temperature stress is one of the major abiotic stresses limiting cotton production. Identifying genetic loci and genes for heat tolerance is crucial for breeding heat-tolerant varieties. Methods: Given the complexity of heat tolerance phenotypes in cotton, this study, which focused on resource materials, identified an A/C SNP mutation at position 5486185 on chromosome D06 within the heat tolerance interval through genome-wide association studies (GWAS) of natural Gossypium hirsutum populations. Results: A total of 308 resource materials were identified and evaluated for their heat tolerance phenotypes over two years of field research. Kompetitive allele-specific PCR (KASP) molecular markers were developed on the basis of the D06-5486185 SNP to characterize the heat tolerance phenotypes of these 308 resource materials. Genotyping for heat tolerance-related traits and agronomic traits was also performed. Materials with the C/C haplotype at position D06-5486185 presented increased heat tolerance (higher pollen viability (PV), leaf area (LA), chlorophyll (Chl) and number of bolls on the third fruit branch (FB3) and a lower number of dry buds (DBs) and drop rate (DR)) without negatively impacting key yield traits. This locus is located in the intergenic region of two adjacent bZIP transcription factor genes (GH_D06G0408 and GH_D06G0409). Expression analysis revealed that the expression levels of these two genes were significantly greater in heat-tolerant accessions (C/C type) than in sensitive accessions and that their expression levels were significantly correlated with multiple heat-tolerant phenotypes. Conclusions: In summary, this study developed a Kompetitive Allele Specific PCR (KASP) marker associated with heat tolerance in G. hirsutum and identified two key heat tolerance candidate genes. These results provide an efficient marker selection tool and important genetic resources for the molecular breeding of heat-tolerant G. hirsutum, laying an important foundation for further establishing a molecular marker-assisted breeding system for heat tolerance in G. hirsutum. Full article

Dendrobium officinale, an orchid of significant medicinal and ornamental value, exhibits poorly characterized hormonal regulation of flower bud differentiation. To address this knowledge gap, we employed an integrated multi-omics approach combining physiological, transcriptomic, metabolomic, and network analyses to elucidate the molecular mechanisms underlying the coordinated action of 6-Benzylaminopurine (6-BA) and Gibberellin A3 (GA₃) in this critical developmental process. Our key findings reveal that combined 6-BA and GA₃ treatment significantly enhances flower bud differentiation and induces stage-specific fluctuations in soluble sugar, protein, and starch levels. Transcriptomic profiling identified 11,994 differentially expressed genes (DEGs), with DEGs specific to the hormone-treated stage showing pronounced enrichment in plant hormone signal transduction and plant–pathogen interaction pathways. Metabolomic analysis uncovered 18 stage-specific differential metabolites (DAMs) during hormone treatment, including GA₃, 6-BA, and OPDA, whose accumulation dynamics were strongly correlated with the progression of differentiation. Weighted gene co-expression network analysis (WGCNA) pinpointed key hub genes within the yellow module, notably transcription factors from the C2H2, bZIP, and NAC families. Their interaction network demonstrated significant correlation with the transcriptional regulation of hormone-responsive genes. Significantly, this study establishes the first molecular framework for 6-BA and GA₃ regulation of flower bud differentiation in D. officinale. We demonstrate a metabolomic–transcriptomic coordination network driven by these hormones, where key hub genes form regulatory modules with transcription factors. Dynamic shifts in endogenous hormones reinforce the flowering signal. These findings provide crucial molecular targets for precision flowering control and molecular breeding strategies in orchids. Full article

Polyembryonic maize, capable of producing multiple seedlings from a single kernel, holds great potential value in agricultural and industrial applications, but the seedling quality needs to be improved. In this study, seedlings of two waxy maize (Zea mays L. sinensis Kulesh) inbred lines, D35 (a polyembryonic line with twin shoots) and N6110 (single-shoot), exhibited similar relative growth rates during 1 to 5 days post-germination. UPLC-MS/MS profiling of 3- to 5-day-old seedling roots and shoots revealed that H2JA, MeSAG, and IAA-Val-Me were the common differentially accumulated metabolites (DAMs) of the 3-day-old vs. 5-day-old seedlings of D35 and N6110 in the same tissues, and MeSAG, tZ9G, cZROG, and DHZROG were identified in D35 vs. N6110 across the same tissues and the same periods. RNA-seq analyses showed various processes involved in seedling development, including DNA replication initiation, rhythmic processes, the cell cycle, secondary metabolic processes, and hormone biosynthetic regulation. The differentially expressed genes (DEGs) between D35 and N6110 were significantly enriched in organic hydroxy compound biosynthetic, alcohol biosynthetic, organic hydroxy compound metabolic, abscisic acid biosynthetic, and apocarotenoid biosynthetic processes. The KEGG-enriched pathways of DAMs and DEGs identified that AUX1, AHP, A-ARR, JAR1, SIMKK, ERF1, and GID2 might be conserved genes regulating seedling growth. The integrated analyses revealed that 98 TFs were potentially associated with multiple hormones, and 24 of them were identified to be core genes, including 11 AP2/ERFs, 4 Dofs, 2 bZIPs, 2 MADS-box genes, 2 MYBs, 1 GATA, 1 LOB, and 1 RWP-RK member. This study promotes a valuable understanding of the complex hormone interactions governing twin-shoot seedling growth and offers potential targets for improving crop establishment via seedling quality. Full article

Rhododendron L., a renowned ornamental species and one of the ten famous flowers in China, is highly regarded for its aesthetic value and extensive applications in landscaping. However, its growth and quality are significantly compromised by drought stress, particularly in regions with dry conditions. To elucidate the drought response mechanisms of Rhododendron, two cultivars, ‘SaKeSiZhiXing’ (SKSZX) and ‘TuRuiMeiGui’ (TRMG), were subjected to natural drought stress, and changes in chlorophyll fluorescence and transcriptomic profiles were examined at 0 days (d), 4 d, and 8 d of drought exposure. An OJIP fluorescence transient (O-J-I-P) analysis revealed a progressive decline in the F_P parameter and an increase in the F_J parameter as drought stress intensified. Additionally, a delayed fluorescence (DF) analysis showed a gradual reduction in the I₁ and I₂ values within the induction and decay curves under prolonged drought conditions. The 820 nm curve indicated the deactivation of a transient phase characterized by a rapid decline, followed by a slow recovery in the modulated reflection (MR) signal. A transcriptomic analysis of leaves identified 24,352, 18,688, and 32,261 differentially expressed genes (DEGs) in SKSZX at 0 d, 4 d, and 8 d of drought treatment, respectively. In contrast, TRMG exhibited more pronounced and earlier drought-induced alterations. These DEGs were primarily enriched in pathways related to phenylpropanoid biosynthesis, plant hormone signaling, photosynthesis, and photosynthesis-antenna proteins. Additionally, 565 transcription factors (TFs) were identified, including bHLH, WRKY, bZIP, MYB-related, MYB, C2H2, and HSF families. The drought-induced changes in TRMG were more substantial and occurred earlier compared to SKSZX, with a greater impairment in the electron transfer capacity at both the donor and acceptor sides of photosystem II (PSII). This study provides valuable insights into the molecular mechanisms underlying drought tolerance in Rhododendron and offers a foundation for molecular breeding strategies aimed at enhancing drought resistance in future cultivars. Full article

Zinc deficiency is a common nutritional disorder with detrimental health consequences. Whether parental zinc deficiency induces intergenerational effects remains largely unknown. We investigated the effects of a combined maternal and paternal zinc deficiency on offspring’s metabolic outcomes and gene expression changes in Drosophila melanogaster. The parent flies were raised on zinc-deficient diets throughout development, and their progeny were assessed. Offspring from zinc-deprived parents exhibited a significant (p < 0.05) increase in body weight and whole-body zinc levels. They also displayed disrupted glucose metabolism, altered lipid homeostasis, and diminished activity of antioxidant enzymes. Gene expression analysis revealed significant (p < 0.05) alterations in zinc transport genes, with increases in mRNA levels of dZIP1 and dZnT1 for female and male offspring, respectively. Both sexes exhibited reduced dZnT35C mRNA levels and significant (p < 0.05) increases in the mRNA levels of DILP2 and proinflammatory markers, Eiger and UPD2. Overall, female offspring showed higher sensitivity to parental zinc deficiency. Our findings underscore zinc’s crucial role in maintaining health and the gender-specific responses to zinc deficiency. There is the need for further exploration of the underlying mechanisms behind these intergenerational effects. Full article

The basic leucine zipper (bZIP) transcription factor (TF) family is one of the biggest TF families identified so far in the plant kingdom, functioning in diverse biological processes including plant growth and development, signal transduction, and stress responses. For Perilla frutescens, a novel oilseed crop abundant in polyunsaturated fatty acids (PUFAs) (especially α-linolenic acid, ALA), the identification and biological functions of bZIP members remain limited. In this study, 101 PfbZIPs were identified in the perilla genome and classified into eleven distinct groups (Groups A, B, C, D, E, F, G, H, I, S, and UC) based on their phylogenetic relationships and gene structures. These PfbZIP genes were distributed unevenly across 18 chromosomes, with 83 pairs of them being segmental duplication genes. Moreover, 78 and 148 pairs of orthologous bZIP genes were detected between perilla and Arabidopsis or sesame, respectively. PfbZIP members belonging to the same subgroup exhibited highly conserved gene structures and functional domains, although significant differences were detected between groups. RNA-seq and RT-qPCR analysis revealed differential expressions of 101 PfbZIP genes during perilla seed development, with several PfbZIPs exhibiting significant correlations with the key oil-related genes. Y1H and GUS activity assays evidenced that PfbZIP85 downregulated the expression of the PfLPAT1B gene by physical interaction with the promoter. PfLPAT1B encodes a lysophosphatidate acyltransferase (LPAT), one of the key enzymes for triacylglycerol (TAG) assembly. Heterogeneous expression of PfbZIP85 significantly reduced the levels of TAG and UFAs (mainly C18:1 and C18:2) but enhanced C18:3 accumulation in both seeds and non-seed tissues in the transgenic tobacco lines. Furthermore, these transgenic tobacco plants showed no significantly adverse phenotype for other agronomic traits such as plant growth, thousand seed weight, and seed germination rate. Collectively, these findings offer valuable perspectives for understanding the functions of PfbZIPs in perilla, particularly in lipid metabolism, showing PfbZIP85 as a suitable target in plant genetic improvement for high-value vegetable oil production. Full article

Many veterans deployed to Gulf War areas suffer from persistent chronic diarrhea that is disabling and affects their quality of life. The causes for this condition have eluded investigators until recently and recent literature has shed light on the effect of vitamin D on the brain–gut axis. This study focused on determining clinical causes contributing to diarrhea and assessed whether reversing the identified causes, specifically vitamin D deficiency (VDD), could reduce the incidence of diarrhea in Gulf War veterans (GWVs). All patients completed a workup that included serologies (IBD, celiac), routine laboratory tests (CBC, chemistry panels, TSH, T4, CRP), cultures for enteric pathogens (C diff, bacteria, viruses, small intestinal bacterial overgrowth (SIBO)), and upper and lower endoscopies with histology and a trial of cholestyramine to exclude choleretic diarrhea and rifaximin for dysbiosis. A total of 4221 veterans were screened for chronic diarrhea, yielding 105 GWVs, of which 69 GWVs had irritable bowel syndrome with diarrhea (IBS-D). Paired t-tests demonstrated that all GWVs had VDD (t-11.62, df68 and sig(2-tailed) 0.0001) (defined as a vitamin D level less than 30 ng/mL with normal ranges of 30–100 ng/mL) but no positive serologies, inflammatory markers, abnormal endoscopies, cultures, or histology to explain their persistent diarrhea. There was no correlation with age, BMI, or inflammation. Some zip codes had a higher frequency of GWVs with VDD, but the number of deployments had no impact. Treatment with vitamin D supplementation (3000–5000 units), given in the morning, based on weight, reduced the number of bowel movements per day (p < 0.0001) without causing hypercalcemia. We suggest that VDD is important in the etiology of IBS-D in GWVs and that vitamin D supplementation significantly reduces diarrhea. Full article

Mitogen-activated protein kinases (MAPKs) play essential roles in the process of stress response and plant growth and development. MAPK family genes have been identified in many plant species. In this study, 18 LsMAPK genes were identified in lettuce (Lactuca sativa). The LsMAPK members were divided into Group A, B, C, and D by phylogenetic tree analysis among Arabidopsis, rice, and lettuce. Cis-elements, which relate to abiotic stress, phytohormone response, and transcription factor binding site, were identified to exist in the promoter region of LsMAPK genes. Chromosomal location analysis showed the LsMAPK genes were distributed on eight chromosomes except chromosome 6. Interaction network analysis showed that LsMAPKs could interact with MAPK kinase (MAPKK), protein-tyrosine-phosphatase (PTP), and transcription factors (WRKY, bZIP). Quantitative reverse transcription PCR (qRT-PCR) showed that LsMAPK genes were induced by different abiotic stresses, hormone response, and stem enlargement. The comprehensive identification and characterization of LsMAPK genes in stem lettuce will lay a theoretical foundation for the functional analysis of LsMAPK genes and advance our knowledge of the regulatory mechanism of MAPK genes in plants. Full article

Salt stress is one the most destructive abiotic stressors, causing yield losses in wheat worldwide. A prerequisite for improving salt tolerance is the identification of traits for screening genotypes and uncovering causative genes. Two populations of F₃ lines developed from crosses between sensitive and tolerant parents were tested for salt tolerance at the seedling stage. Based on their response, the offspring were classified as salt sensitive and tolerant. Under saline conditions, tolerant genotypes showed lower Na⁺ and proline content but higher K⁺, higher chlorophyll content, higher K⁺/Na⁺ ratio, higher PSII activity levels, and higher photochemical efficiency, and were selected for further molecular analysis. Five stress responsive QTL identified in a previous study were validated in the populations. A QTL on the short arm of chromosome 1D showed large allelic effects in several salt tolerant related traits. An expression analysis of associated candidate genes showed that TraesCS1D02G052200 and TraesCS5B02G368800 had the highest expression in most tissues. Furthermore, qRT-PCR expression analysis revealed that ZIP-7 had higher differential expressions under saline conditions compared to KefC, AtABC8 and 6-SFT. This study provides information on the genetic and molecular basis of salt tolerance that could be useful in development of salt-tolerant wheat varieties. Full article

The cyanobacterium Anabaena sp. PCC 7120 forms filaments of communicating cells. Under conditions of nitrogen scarcity, some cells differentiate into heterocysts, allowing the oxygen-sensitive N₂-reduction system to be expressed and operated in oxic environments. The key to diazotrophic growth is the exchange of molecules with nutritional and signaling functions between the two types of cells of the filament. During heterocyst differentiation, the peptidoglycan sacculus grows to allow cell enlargement, and the intercellular septa are rebuilt to narrow the contact surface with neighboring cells and to hold specific transport systems, including the septal junction complexes for intercellular molecular transfer, which traverse the periplasm between heterocysts and neighboring vegetative cells through peptidoglycan nanopores. Here we have followed the spatiotemporal pattern of peptidoglycan incorporation during heterocyst differentiation by Van-FL labeling and the localization and role of proteins MreB, MreC and MreD. We observed strong transitory incorporation of peptidoglycan in the periphery and septa of proheterocysts and a maintained focal activity in the center of mature septa. During differentiation, MreB, MreC and MreD localized throughout the cell periphery and at the cell poles. In mreB, mreC or mreD mutants, instances of strongly increased peripheral and septal peptidoglycan incorporation were detected, as were also heterocysts with aberrant polar morphology, even producing filament breakage, frequently lacking the septal protein SepJ. These results suggest a role of Mre proteins in the regulation of peptidoglycan growth and the formation of the heterocyst neck during differentiation, as well as in the maintenance of polar structures for intercellular communication in the mature heterocyst. Finally, as previously observed in filaments growing with combined nitrogen, in the vegetative cells of diazotrophic filaments, the lack of MreB, MreC or MreD led to altered localization of septal peptidoglycan-growth bands reproducing an altered localization of FtsZ and ZipN rings during cell division. Full article

Abiotic stresses adversely influence crop productivity and salt stress is one limiting factor. Plants need to evolve their defense mechanisms to survive in such fluctuating scenarios at either the biochemical, physiological, or molecular level. The analytical/critical investigations of cotton (Gossypium hirsutum) plants that involve looking into transcriptomic and metabolomic profiles could give a comprehensive picture of the response of the cotton plant to salt stress. This study was conducted on pre-treated cotton seeds by soaking them in a 3% sodium chloride (NaCl) solution at room temperature for 0.5, 1, and 1.5 h. In total, 3738 and 285 differentially expressed genes (DEGs) and metabolites, respectively, were discovered. The prominent DEGs included AtCCC1, EP1, NHE, AtpOMT, GAST1, CLC-c, ARP, AtKIN14, AtC3H2, COP9, AtHK-2, and EID1 to code for the regulation of seed growth, abscisic acid receptor PYR/PYL, a cellular response regarding stress tolerance (especially to salt) and germination, jasmonic acid, salicylic acid, and auxin-activated signaling pathways. A more significant amount of transcription factors, including the ethylene-responsive TFs ERF (205), bHLH (252), ZF-domains (167), bHLH (101), MYB (92), NAC (83), GATA (43), auxin-responsive proteins (30), MADs-box (23), bZIP (27), and HHO (13) were discovered in samples of NaCl-pretreated cotton seedlings under different treatments. The functional annotations of DEGs exposed their important roles in regulating different phytohormones and signal-transduction-mediated pathways in salt-treated seeds. The metabolites analysis revealed differential accumulation of flavonols, phenolic acid, amino acids, and derivatives in seedling samples treated for 0.5 h with NaCl. The conjoint analysis that showed most of the DEGs were associated with the production and regulation of glucose-1-phosphate, uridine 5′-diphospho-D-glucose, and 2-deoxyribose 1-phosphate under salt stress conditions. These results indicated positive effects of NaCl 0.5 h treatments on seedlings’ germination and growth, seemingly by activating specific growth-promoting enzymes and metabolites to alleviate adverse effects of salt stress. Hence, seed pre-treatment with NaCl can be beneficial in future cotton management and breeding programs to enhance growth and development under salt stress. Full article

Basic leucine zipper (bZIP), a conserved transcription factor widely found in eukaryotes, has important regulatory roles in plant growth. To understand the information related to the bZIP gene family in walnut, 88 JrbZIP genes were identified at the genome-wide level and classified into 13 subfamilies (A, B, C, D, E, F, G, H, I, J, K, M, and S) using a bioinformatic approach. The number of exons in JrbZIPs ranged from 1 to 12, the number of amino acids in JrbZIP proteins ranged from 145 to 783, and the isoelectric point ranged from 4.85 to 10.05. The majority of JrbZIP genes were localized in the nucleus. The promoter prediction results indicated that the walnut bZIP gene contains a large number of light-responsive and jasmonate-responsive action elements. The 88 JrbZIP genes were involved in DNA binding and nucleus and RNA biosynthetic processes of three ontological categories, molecular functions, cellular components and biological processes. The codon preference analysis showed that the bZIP gene family has a stronger bias for AGA, AGG, UUG, GCU, GUU, and UCU than other codons. Moreover, the transcriptomic data showed that JrbZIP genes might play an important role in floral bud differentiation. The results of a protein interaction network map and kegg enrichment analysis indicated that bZIP genes were mainly involved in phytohormone signaling, anthocyanin synthesis and flowering regulation. qRT-PCR demonstrated the role of the bZIP gene family in floral bud differentiation. Co-expression network maps were constructed for 29 walnut bZIP genes and 6 flowering genes, and JrCO (a homolog of AtCO) was significantly correlated (p < 0.05) with 13 JrbZIP genes in the level of floral bud differentiation expression, including JrbZIP31 (homolog of AtFD), and JrLFY was significantly and positively correlated with JrbZIP10,11,51,59,67 (p < 0.05), and the above results suggest that bZIP family genes may act together with flowering genes to regulate flower bud differentiation in walnut. This study was the first genome-wide report of the walnut bZIP gene family, which could improve our understanding of walnut bZIP proteins and provide a solid foundation for future cloning and functional analyses of this gene family. Full article

Chilling injury poses a serious threat to seed emergence of spring-sowing maize in China, which has become one of the main climatic limiting factors affecting maize production in China. It is of great significance to mine the key genes controlling low-temperature tolerance during seed germination and study their functions for breeding new maize varieties with strong low-temperature tolerance during germination. In this study, 176 lines of the intermated B73 × Mo17 (IBM) Syn10 doubled haploid (DH) population, which comprised 6618 bin markers, were used for QTL analysis of low-temperature germination ability. The results showed significant differences in germination related traits under optimum-temperature condition (25 °C) and low-temperature condition (10 °C) between two parental lines. In total, 13 QTLs were detected on all chromosomes, except for chromosome 5, 7, 10. Among them, seven QTLs formed five QTL clusters on chromosomes 1, 2, 3, 4, and 9 under the low-temperature condition, which suggested that there may be some genes regulating multiple germination traits at the same time. A total of 39 candidate genes were extracted from five QTL clusters based on the maize GDB under the low-temperature condition. To further screen candidate genes controlling low-temperature germination, RNA-Seq, in which RNA was extracted from the germination seeds of B73 and Mo17 at 10 °C, was conducted, and three B73 upregulated genes and five Mo17 upregulated genes were found by combined analysis of RNA-Seq and QTL located genes. Additionally, the variations of Zm00001d027976 (GLABRA2), Zm00001d007311 (bHLH transcription factor), and Zm00001d053703 (bZIP transcription factor) were found by comparison of amino sequence between B73 and Mo17. This study will provide a theoretical basis for marker-assisted breeding and lay a foundation for further revealing molecular mechanism of low-temperature germination tolerance in maize. Full article

Zrt2 is a zinc transporter of the ZIP family. It is predicted to be located in the plasma membrane and it is essential for Candida albicans zinc uptake and growth at acidic pH. Zrt2 from C. albicans is composed of 370 amino acids and contains eight putative transmembrane domains and an extra-membrane disordered loop, corresponding to the amino acid sequence 126–215. This protein region contains at least three possible metal binding motifs: HxHxHxxD (144–153), HxxHxxEHxD (181–193) and the Glu- and Asp- rich sequence DDEEEDxE (161–168). The corresponding model peptides, protected at their termini (Ac-GPHTHSHFGD-NH₂, Ac-DDEEEDLE-NH₂ and Ac-PSHFAHAQEHQDP-NH₂), have been investigated in order to elucidate the thermodynamic and coordination properties of their Zn²⁺ and Cu²⁺ complexes, with the further aim to identify the most effective metal binding site among the three fragments. Furthermore, we extended the investigation to the peptides Ac-GPHTHAHFGD-NH₂ and Ac-PAHFAHAQEHQDP-NH₂, where serine residues have been substituted by alanines in order to check if the presence of a serine residue may favor the displacement of amidic protons by Cu²⁺. In the native Zrt2 protein, the Ac-GPHTHSHFGD-NH₂ region of the Zrt2 loop has the highest metal binding affinity, showing that three alternated histidines separated by only one residue (-HxHxH-) bind Zn²⁺ and Cu²⁺ more strongly than the region in which three histidines are separated by two and three His residues (-HxxHxxxH- in Ac-PSHFAHAQEHQDP-NH₂). All studied Zrt2 loop fragments have lower affinity towards Zn²⁺ than the zinc(II) binding site on the Zrt1 transporter; also, all three Zrt2 regions bind Zn²⁺ and Cu²⁺ with comparable affinity below pH 5 and, therefore, may equally contribute to the metal acquisition under the most acidic conditions in which the Zrt2 transporter is expressed. Full article

In this study, the non-dominated sorting genetic algorithm II (NSGA-II) is used to optimize the annual phase arrangement of distribution transformers connected to primary feeders to improve three-phase imbalance and reduce power loss. Based on the data of advanced metering infrastructure (AMI), a quasi-real-time ZIP load model and typical sample distribution systems in Taiwan are constructed. The equivalent circuit models and solution algorithms for typical distribution systems in Taiwan are built using the commercial software package MATLAB. A series of simulations, analyses, comparisons, and explorations is executed. Finally, the quantitative evaluation results for improving the voltage imbalance and reducing the power loss are summarized. For the series of studies, the percentage reductions in (1) total power imbalance $T{S}_I$, (2) total line loss $T{L}_L$, (3) average voltage drop $A{V}_D$, (4) total voltage imbalance factors for zero/negative sequences $T{d}_0/T{d}_2$, and (5) neutral current of the main transformer $I_{LCO}$ are up to 45.48%, 4.06%, 16.61%, 63.99%, 21.33%, and 88.01%, respectively. The results obtained in this study can be applied for energy saving and can aid the authorities to implement sustainable development policies in Taiwan. Full article