Saline-alkali stress limits crop establishment and productivity, particularly in arid and semi-arid regions. Highland barley (Hordeum vulgare L. var. nudum Hook. f) is an important cereal crop on the Qinghai-Tibet Plateau, but the molecular mechanisms underlying its tolerance to saline-alkali stress remain poorly understood. To investigate the molecular basis of genotypic variation in saline-alkali tolerance, the tolerant genotype L86 and sensitive genotype L38 were exposed to saline-alkali stress for 24 h. Results indicated that stress inhibited seedling growth in both genotypes, although L86 maintained significantly greater shoot elongation than L38. RNA sequencing identified more differentially expressed genes (DEGs) in L86 than in L38, largely because of the greater number of upregulated genes in L86. Functional enrichment analysis showed that upregulated DEGs in L86 were preferentially involved in glutathione metabolism; stilbenoid, diarylheptanoid, and gingerol biosynthesis; phenylpropanoid and flavonoid biosynthesis; starch and sucrose metabolism; and several amino acid metabolic pathways. Genes encoding glutathione S-transferases, phenylpropanoid- and flavonoid-related enzymes, β-amylase, and trehalose-6-phosphate phosphatase displayed contrasting expression patterns between the two genotypes, suggesting genotype-dependent regulation of antioxidant defense, secondary metabolism, and carbon allocation. In total, 189 transcription factor genes from 35 families were identified. L86 showed broader transcriptional activation, particularly among members of the ERF, MYB, WRKY, bHLH, and NAC families, whereas downregulated transcription factors predominated in L38. In contrast, photosynthesis- and light-harvesting-related genes were commonly downregulated in both genotypes. Quantitative real-time PCR analysis of selected genes generally confirmed the RNA-sequencing results. The greater early-stage tolerance of L86 was associated with broader transcriptional activation and coordinated regulation of antioxidant defense, secondary metabolism, carbohydrate metabolism, amino acid metabolism, and transcription factor networks. These findings provide candidate genes and regulatory pathways for further functional investigation and the genetic improvement of saline-alkali tolerance in highland barley.
Foliar Zn fertilization is an important agronomic practice for correcting Zn deficiency and achieving Zn biofortification in crops. However, the long-term temporal dynamics of leaf Zn concentration following foliar Zn application and the associated leaf gene expression patterns remain poorly understood. In the present study, ZnSO4 was foliar-applied to soybean (Glycine max (L.) Merr.) at different growth stages, and Zn concentrations and transcriptome profiles of the Zn-applied leaves were tracked to characterize the temporal changes in leaf Zn concentration and investigate the associated gene expression patterns. Regardless of the Zn application time, the Zn concentration in the Zn-applied leaves decreased after the onset of reproductive growth. This suggests a temporal association between the decline in leaf Zn concentration and the transition from vegetative to reproductive growth. Transcriptomic profiling and weighted gene co-expression network analysis revealed a gene module that was significantly correlated with the observed decline in leaf Zn concentration. The MAPK cascades and calcium signaling pathways were enriched in this module and may be involved in the regulation of this change in leaf Zn concentration. Additionally, candidate Zn transporters (GmZIP12, GmZIP13, GmZIP23, GmHMA7, GmHMA11, GmHMA12, GmMTP2.1, GmMTP5.2, and GmYSL3Lb) and transcription factors (from families such as bZIP, NAC, bHLH, MYB, and ERF) potentially involved in the observed decline in leaf Zn concentration were also identified. The present study found that the Zn concentration in Zn-applied soybean leaves mainly declined after the onset of reproductive growth. In parallel, potential signaling pathways and candidate genes that may be involved in the observed decline in leaf Zn concentration were identified. The temporal leaf Zn concentration dataset and the associated transcriptomic profiles provide foundational information for future investigations into the translocation of foliar-applied Zn and the underlying molecular mechanisms in soybean.
Sulfotransferases (SOTs) regulate plant sulfur metabolism and secondary metabolism, yet single-reference-based analysis cannot fully reveal the population evolutionary characteristics of the tomato SOT family. In this study, SOT genes were identified from pan-genomic data of 61 tomato accessions spanning the full domestication gradient, and their expansion mechanisms and functional differentiation were systematically dissected across phylogeny, structural variation, selection pressure, transcriptome and metabolome dimensions. The tomato SOT family fell into three subfamilies, TPST, NFST and SULT. The SULT subfamily underwent the most prominent expansion and accumulated abundant TE insertions. Whole-genome duplication, tandem duplication and dispersed duplication collectively drove family expansion, with gene clusters harboring extensive structural variation being dominated by tandem-duplicated genes. Dispensable genes harbored significantly higher TE abundance than core genes. The entire family evolved under purifying selection, while dispensable genes and high-copy clusters experienced relaxed selective constraints. The wild-enriched C2-1 cluster carried positively selected sites that may facilitate stress adaptation in wild tomatoes. The SULT subfamily exhibited the greatest transcriptional divergence, and distinct PAV and CNV clusters played differentiated roles in metabolic regulation. Finally, a dedicated web platform was constructed to host all multi-omics data and analytical results, supporting data browsing, visualization and batch download. Collectively, duplication events, TE insertions, structural variation and differential selection jointly shaped the evolutionary landscape of the tomato SOT family, providing theoretical support for sulfur metabolism research and tomato germplasm improvement. The accompanying web platform further enables open data sharing and research reproducibility.
Autopolyploids generally exhibit larger phenotypes than their progenitors, suggesting higher biomass and enhanced phytoremediation potential. This study tested this hypothesis using a previously uncharacterized, novel artificial autooctaploid of a Zn- and Cd-tolerant ecotype of Arabidopsis arenosa, derived from a natural tetraploid cytotype. Vegetative development, metal tolerance, and accumulation capacity were compared between the parental tetraploids and the derived autooctaploids under controlled laboratory conditions. During the intermediate growth period (days 56–72), octaploid plants had significantly lower biomass than tetraploids, but this difference was no longer significant by day 84. This transient difference coincided with the earlier entry of octaploids into the generative phase. Despite their autopolyploid origin, the octaploid specimens were fully fertile, enabling sexual reproduction via seeds. They could also be propagated using encapsulated vegetative tissues (artificial seeds). Under extreme heavy metal stress (8 mM Zn and/or 0.2 mM Cd for 9 days), octaploids showed a significantly higher Zn concentration in their roots than tetraploids, while both cytotypes exhibited similar overall resilience to metal toxicity. The autooctaploids demonstrate significant potential for land reclamation due to their ability to tolerate and sequester extreme concentrations of zinc and cadmium without visible signs of toxicity. Under the controlled conditions used here, octaploids showed a > 50
Mango (Mangifera indica L.) is one of the most economically important tropical fruits globally. It is widely appreciated for its distinctive flavor, vibrant color, and high nutritional value. This study aimed to characterize the quality traits and bioactive compound content of 82 mango genotypes grown under the agroclimatic conditions of the Brazilian semi-arid region, and to identify the most promising candidates for fresh consumption using a multivariate selection index. Genotypes were evaluated over two consecutive seasons in a design comprising four experimental plots per genotype (one clonal plant per plot). Forty fruits per genotype (10 fruits per plot) were evaluated. The parameters evaluated in this study were fruit mass (g), transverse diameter (mm), length (mm), pulp yield (
