Drought stress severely impairs maize germination and early seedling growth, posing a significant threat to global food security. To address this, superabsorbent polymers (SAPs) are being explored as an effective seed-coating method to improve water availability during the crucial germination phase. However, their comparative efficacy and underlying molecular mechanisms remain insufficiently understood. In this study, we evaluated the effects of three distinct SAPs, two fossil-based (MERCK, SWT) and one natural-based (ABG), on maize germination and seedling development under controlled drought conditions. We integrated physiological (germination rate and NA + ), biochemical (total phenol content), and transcriptomic (mRNA-seq) analyses to provide a comprehensive multi-level assessment. Physiologically, among all SAPs, the MERCK was the most effective, resulting in the highest proportion of normal seedlings and the fewest abnormal seedlings. In contrast, the SWT treatment was detrimental, increasing the proportion of abnormal seedlings, suggesting phytotoxic effects. Biochemically, all SAP treatments resulted in elevated seedling sodium (Na + ) content, indicating potential secondary ionic stress. Transcriptomic analysis further elucidated these observations, revealing a set of differentially expressed genes, including those involved in stress response ( BADH , FACT , XCP2 ), SAP-specific response ( DRB5 , RAF35 , EDR1 ), and combined salt/drought stress ( WRKY47 , DTX20 ), as promising candidate biomarkers for stress assessment and breeding. Our research highlights the nuanced efficacy of SAPs; specifically, the MERCK SAP yielded more favorable outcomes, while other formulations occasionally caused unexpected phytotoxicity. The identified gene expression patterns not only mechanistically explain the observed physiological responses but also offer a valuable panel of molecular biomarkers. These markers can be used to screen novel SAP applications, such as seed coatings, and to breed stress-resilient maize cultivars.

Five advanced breeding lines of sweet potato were assessed for polyethylene glycol (PEG)-6000-mediated osmotic stress tolerance in vitro . Significant variation among the morphophysiological properties and antioxidative enzyme activities was observed under different levels of PEG (0, 0.1, and 0.2 MPa) incorporated in Murashige and Skoog (MS) medium. An induction of antioxidative enzymes—superoxide dismutase (SOD, Enzyme Commission [EC] 1.15.1.1), catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.1), guaiacol peroxidase (GPX, EC 1.11.1.7), monodehydroascorbate reductase (MDHAR, EC 1.6.5.4), dehydroascorbate reductase (DHAR, EC 1.8.5.1), glutathione reductase (GR, EC 1.6.4.2), and polyphenol oxidase (PPO, EC 1.14.18.1)—was observed under stress compared to the control, and this induction was pronounced in the tolerant genotypes than in the susceptible ones. Among the antioxidant enzymes, CAT showed a strong positive correlation with GPX (Pearson’s correlation coefficient [ r ] = 0.73), whereas MDHAR was strongly and positively correlated with APX ( r = 0.73) and PPO ( r = 0.68). A significant increase in antioxidative enzyme activities was associated with lower growth retardation, as evident from the correlation study. Genotypes SP–30, followed by SP–18, possessed high principal component (PC1) scores and were rich in antioxidative enzymes, whereas genotypes SP–24, SP–26, and SP–28 exhibited lower enzyme activities and skewed morphological traits. The overall pattern of osmotic stress tolerance among the tested advanced sweet potato breeding lines followed the order: SP–30 > SP–18 > SP–26 > SP–24 > SP–28. The outcome of the study encourages the advancement of SP–30 for inclusion in future breeding strategies and/or its release following the official variety release procedures.

Introduction Somatic embryogenesis (SE) is an essential propagation technology for Hevea brasiliensis , yet its application remains limited by the strong genotype dependence of embryogenic capacity. Methods To elucidate the metabolic basis of this variation, we conducted integrated metabolomic and transcriptomic analyses across four SE developmental stages in a high-embryogenic (HE) and a low-embryogenic (LE) genotype, including explants, induced callus, non-embryogenic / embryogenic callus, and cotyledonary embryos (HE-specific). Results A total of 1,383 metabolites belonging to 11 major classes were identified, with flavonoids, phenolic acids, and amino acids being the predominant groups. PCA and hierarchical clustering revealed that metabolic variation was driven primarily by developmental stage rather than genotype. Differential metabolite profiling revealed strong stage specificity, with the callus-to-differentiation transition (LE-C vs. HE-EC) exhibiting the greatest metabolic divergence between genotypes. KEGG enrichment consistently highlighted flavonoid biosynthesis as a key differentiating pathway. Comparative analyses revealed a conserved-to-divergent pattern of metabolic regulation. During the explant-to-callus transition, both genotypes exhibited highly conserved flavonoid biosynthesis responses, with 67.5% of genes and 85.7% of metabolites showing concordant regulation (either both up-regulated or both down-regulated). In contrast, during the callus-to-differentiation transition, pronounced metabolic divergence emerged, with only 37.5% of genes and 6.7% of metabolites showing concordant regulation, and 11 flavonoid-related genes displaying opposite regulatory directions between genotypes. Notably, the HE genotype exhibited coordinated repression of CHS, CHI, F3H, UFGT , and anthocyanin biosynthesis, accompanied by decreased accumulation of naringenin and glycosylated flavonoids, along with an overall attenuation of dihydroflavonol accumulation. Conversely, the LE genotype maintained relatively active flavonoid biosynthesis and glycosylation, along with increased amino sugar and nucleotide sugar metabolism. Discussion Our results provide comprehensive metabolomic evidence for stage-dependent metabolic reprogramming during SE in H. brasiliensis . The contrasting patterns of flavonoid metabolism between genotypes at the callus-to-differentiation transition—systematic downregulation in the HE genotype versus sustained activation in the LE genotype—are consistent with the hypothesis that a timely reallocation of metabolic flux from secondary to primary metabolism may favor somatic embryo development. This study identifies the callus-to-differentiation transition as a critical metabolic checkpoint and suggests flavonoid biosynthesis genes, particularly CHS and glycosyltransferases, as potential targets for improving SE efficiency in recalcitrant genotypes.

Introduction Plastic film mulching is a critical practice in arid agroecosystems, yet its spatiotemporal impacts on the rhizosphere microbiome remain poorly understood. Methods Here, we investigated how no-mulching (CK), on-film hole sowing (UPM), and film-side planting (FPM) shape the bacterial and fungal communities in the maize rhizosphere across developmental stages (V12 and R6) and soil depths (10, 20, and 30 cm). Results Concurrently, both mulching strategies increased maize yield relative to CK, with FPM ultimately outperforming UPM (19.05% vs. 6.24%). Amplicon sequencing showed that mulching strongly structured the rhizosphere microbiome with clear spatiotemporal variation. Bacterial and fungal communities exhibited contrasting patterns: bacteria responded mainly in topsoil at V12 and across all depths by R6, whereas fungi responded across the soil profile at V12, with responses weakening with depth at R6. Mulching—particularly UPM—reduced key taxa, including the nitrifying genus Nitrospira and symbiotic Glomeromycota . Correlation analyses revealed significant associations between these taxonomic shifts and maize yield components, consistent with Nitrospira’s preference for aerobic conditions. Functional predictions suggested UPM favored communities with higher representation of anaerobic decomposition pathways, whereas FPM supported greater potential for aerobic heterotrophy and nitrogen-related processes. Discussion Although microbial shifts were correlated with yield components, yield increases were likely dominated by the direct physical effects of mulching. Overall, distinct mulching strategies generated divergent rhizosphere trajectories, with FPM potentially offering a more sustainable option for dryland maize production.

Dual reporter assay has been widely used for quantification of gene expression in various model systems. However, the assay is dependent on commercial kits, which may be inhibitory for many low-budget academic laboratories or high throughput screening. Here, we systematically characterized seven commonly used or potential reporters, and identified NanoLuc-GFP pair as the optimal kit-independent and accurate dual reporter in Nicotiana benthamiana . The NanoLuc-GFP system exhibited high stability, which can largely reduce the interference caused by biological variability and dramatic environmental fluctuations. Furthermore, it exhibits greater sensitivity compared to the conventional FLuc/RLuc system commercially available.

Brassica juncea is an important oilseed and vegetable crop whose flowers are typically yellow, largely owing to carotenoid pigmentation. Here, we report a novel, heritable apricot-flowered variant designated ‘Caijie,’ from a wild B. juncea accession. Metabolomic profiling revealed that the distinctive petal coloration was primarily attributable to anthocyanin accumulation. Genetic mapping via bulked segregant analysis (BSA) mapped the apricot-flowered trait to a single dominant locus within a 9.76-Mb interval on chromosome B03. Among the 1,406 annotated genes in this region, Production of Anthocyanin Pigment 2 ( BjB03.PAP2 ), which encodes an R2R3-MYB transcription factor, emerged as the most likely candidate gene. Consistent with this, transcriptomic analysis revealed coordinated upregulation of multiple structural genes involved in the anthocyanin biosynthesis pathway in the apricot-flowered variant. Further sequence analysis revealed a (TC) n dinucleotide repeat polymorphism in the promoter of BjB03.PAP2 , representing a structural variation that is likely responsible for enhanced transcriptional activity and subsequent anthocyanin production in petals. This study unveils a previously unrecognized genetic mechanism underlying flower color variation in B. juncea , offering new insights into the evolution of floral pigmentation and a valuable genetic resource for breeding ornamental Brassica crops.

One of the main challenges in agriculture is the increasing demand to enhance plant yield per hectare. This is crucial not only for boosting food production to support a growing global population but also for minimizing land use for agricultural purposes. Seed yield is of particular importance since seeds are the primary source of carbohydrates and oil. The number of seeds that develop per plant is influenced by various factors, among which inflorescence architecture is a key trait. The geometrical organization of the inflorescence, known as phyllotaxis, plays an important role during reproductive development across many species. Despite its significance, the molecular mechanisms underlying phyllotactic patterning are still not fully understood. Recently, we demonstrated that the REM genes AtREM34 and AtREM35 are important in establishing phyllotactic patterns in Arabidopsis inflorescences. In this study, we investigated the genetic relationship between these two REM transcription factor genes and a closely related member, AtREM36 . Interestingly, we show that double mutants of these genes display an increased number of siliques produced on the main stem. To explore the translational potential of this finding in the economically important seed crop Brassica napus (rapeseed), we identified and functionally analyzed, through complementation tests, a set of homologous BnaREM genes. This application-driven study uncovers novel genes associated with phyllotaxis and yield in the Brassicaceae family, contributing to our understanding of plant architecture and offering insights into sustainable strategies for crop improvement.

Introduction Extensive research has been conducted on water- limited irrigation strategies and yield component variations in winter wheat (Triticum aestivum L.). However, limited understanding exists regarding the nuanced responses of winter wheat canopies and gene expressions to rehydration events. Methods A field investigation was carried out throughout the winter wheat growing season from 2018 to 2020. Four distinct irrigation schedules were implemented, with water supplementation carefully synchronized with irrigation timing to match the appearance of the third, fourth, fifth, and sixth leaves. Further investigation into the molecular mechanisms of winter wheat rehydration using RNA- seq and ultra- performance liquid chromatography- mass spectrometry (UPLC- MS). Results and discussion Our findings show that delayed rehydration results in reduced total water use across all treatment groups during the reproductive growth period, especially from jointing to flowering. A consistent pattern of reduction was observed in leaf area index (LAI), biomass at maturity (BAM), and plant height as rehydration was progressively delayed. The analysis found no statistically significant differences in phenotypic traits among winter wheat at the four- leaf stage before irrigation. In contrast, delaying rehydration until the fifth- leaf stage in spring had a noticeable impact on phenotypic traits. Implementing delayed rehydration at the four- leaf stage increased grain yield by 8. 31% to 51.23. 23%, mainly through three key yield components: more spikes, optimized grains per spike, and higher 1000- grain weight. Interestingly, the increase in 1000- grain weight was inversely related to total grain quantity after postponed rehydration. Transcriptomic and metabolomic analyses showed that postponed rehydration was associated with flavonoid biosynthesis pathways. Notably, the gene related to dihydrokaempferol- known to be involved in phenylpropanoid, flavonol, and flavone biosynthesis- showed a significant positive correlation with naringenin, chrysin, taxifolin, and prunin. Chlorogenic acid and luteolin also exhibited strong positive correlations with various agronomic traits, such as kernel number and 1000- grain weight. These results suggest the presence of a potential molecular regulator at a critical developmental stage, offering new insights into the mechanisms influencing crop yield under water- restricted irrigation conditions.

Grazing exclusion is a key strategy for restoring degraded alpine grasslands. However, the mechanisms underlying plant species richness and biomass responses to long-term enclosure, particularly species turnover and biomass redistribution, remain unclear. This study compared plant community composition, diversity, and biomass across alpine grasslands on the Qinghai–Tibet Plateau enclosure for 2, 6, 13, and 18 years and free-grazing sites. The Price equation was used to quantitatively partition the independent contributions of lost, gained, and persisting species to changes in diversity and biomass, revealing how the long-term grazing exclusion affects biodiversity and biomass. After 2 years of enclosure, both diversity and biomass increased simultaneously. The biomass increase was primarily derived from the increased biomass of persisting species, while newly gained species contributed little. After 6 years, biomass reached peak value due to further increases in the biomass of persisting gramineous species. However, the loss of weedy species and reduction in species gains caused a diversity decline. After 13 and 18 years of enclosure, the biomass of persisting species began to decline, leading to a gradual decrease in total biomass. In summary, short-term enclosure should prioritize the recovery and conservation of native species rather than the colonization by new species. During the mid-term, attention should be paid to the potential negative impact of overgrown native gramineous species on overall diversity. Long-term grazing exclusion should be avoided where possible to prevent ecosystem degradation. This study provides a novel paradigm for alpine grassland restoration by disentangling community-level dynamic processes.

The big-bracted (Benthamidia) dogwood clade consists of small- to medium-sized deciduous trees within the genus Cornus , known for their showy spring-time floral bract display. Cornus is within the family Cornaceae and order Cornales, and as Cornales is one of the earliest diverging asterids, these taxa have been important for phylogenetic research. Three species within the big-bracted clade, flowering ( Cornus florida ), kousa ( C. kousa ), and Pacific ( C. nuttallii ) dogwoods, are popular ornamental landscape plants in North America, with more than 130 cultivars released. Despite their commercial popularity, numerous research gaps have limited the expansion of fundamental research and dogwood breeding programs. In this present review, we aim to provide a thorough overview of our current understanding of 1) the phylogenetic and biogeographic context, 2) plant biology and major pests and pathogens impacting commercialization, 3) historical commercialization and propagation methods, and 4) genetic and genomic resources and how they have been implemented to understand these species. Research gaps and future directions to advance basic research and breeding of big-bracted ornamental dogwoods are discussed throughout.