Transcriptome Reversal in Sulfate Transporter Involves Abiotic Stress in Sesuvium portulacastrum L.

Sulfur Homeostasis in Rice as a Dynamic Regulatory Network: Functional Genomics, Metabolic Crosstalk, and miR395-Mediated Control.

It is proposed that sulfur metabolism should be viewed as a dynamic resource allocation network rather than a linear assimilation pathway, to help identify regulatory variants that improve sulfur-use efficiency, stress resilience, immunity, and grain quality without compromising yield stability.

Nitrogen Deficiency Outperforms Water Stress in Triggering Strigolactone‐Dependent Responses in Maize

ABSTRACT Strigolactones (SLs) modulate multiple aspects of plant development and stress physiology. This study investigated their role in maize response to abiotic stress by comparing an SL‐biosynthesis mutant (zmccd8) with wild‐type (WT) seedlings grown for 4 weeks in vermiculite under nutrient and water limitation. Plant growth, time‐course pigment accumulation, targeted gene expression, and root transcriptomic profiles were analyzed. Our results showed that zmccd8 plants were largely unable to induce leaf senescence and efficient nutrient remobilization toward younger tissues under nitrogen (N) deficiency, a response previously associated with maize adaptation to low N availability. In parallel, the mutant developed a smaller root system, mainly due to limited adventitious root formation, particularly under N shortage. Root transcriptomic profiling revealed that N deficiency strongly affected WT plants, inducing extensive regulation of pathways involved in nitrogen metabolism and transport, secondary metabolism, ethylene and MAPK signaling, oxidative stress responses, and major transcription factor families. These responses were largely absent in the zmccd8 mutant, suggesting reduced transcriptional plasticity and compromised capacity to cope with stress‐associated oxidative imbalance. Conversely, despite inducing substantial physiological and molecular responses, water stress elicited only modest SL‐dependent regulation, with limited and heterogeneous changes between genotypes. Overall, our findings demonstrate that in maize, SLs act in a stress‐specific manner, playing a predominant role in acclimatisation to nitrogen deficiency through coordinated regulation of senescence, nutrient remobilization, root architecture, and gene expression, while contributing more marginally to water‐stress acclimatisation. These results provide new insights into SLs' role in shaping maize physiological plasticity under abiotic stress conditions.

Root Ion flux and transcriptomic analyses reveal the response mechanisms of Gleditsia sinensis seedlings to salt stress

Gleditsia sinensis Lam. is a widely distributed tree species in China characterized by its remarkable tolerance to barrenness and salinity, making it a valuable candidate for the ecological restoration of saline-alkali lands. Understanding its ion regulatory mechanisms is a prerequisite for salt tolerance evaluation and molecular breeding. However, the molecular mechanisms coordinating root ion fluxes and overall defense strategies in G. sinensis under salt stress remain largely unclear. In this study, we investigated the root ion flux characteristics and underlying molecular mechanisms of hydroponic G. sinensis seedlings under 100 mmol·L⁻¹ NaCl stress using non-invasive micro-test technology (NMT) and transcriptomic sequencing. The results demonstrated that while salt stress induced substantial Na⁺ accumulation, roots actively responded by promoting Na⁺ efflux and H⁺ influx in the elongation zone. Transcriptomic analysis revealed that seedlings adopted a “growth-defense trade-off” strategy. By down-regulating energy-intensive metabolic pathways, the seedlings reallocated limited energy to significantly up-regulate key ion transporters, including AHA11 , AKT1 , and SKOR . This transcriptional reprogramming established a transmembrane proton gradient that drove effective Na⁺ efflux and maintained intracellular K⁺ homeostasis. These findings provide a theoretical basis and genetic resources for targeted molecular breeding of G. sinensis in saline environments.

Emerging roles of silicon in plant signaling networks and microbiome dynamics under salt stress

Silicon (Si) is widely recognized as a beneficial element that can improve plant performance under salt stress. However, a comprehensive understanding of its biological functions requires moving beyond isolated physiological responses toward an integrated view of plant signaling and rhizosphere processes. This narrative review critically synthesizes current evidence and proposes an “inside–outside” framework for Si-associated salt-stress mitigation. Internally, Si treatment has been reported to influence phytohormone homeostasis, particularly abscisic acid, jasmonic acid, and salicylic acid, while also affecting Ca2+-, nitric oxide-, and reactive oxygen species-related processes. These changes are associated with the regulation of stomatal behavior, root water transport, ion homeostasis, osmotic adjustment, antioxidant defense, and stress-responsive gene expression. Rather than acting as a universally established signal integrator, Si may modify the operating state, magnitude, and recovery kinetics of pre-existing stress-response networks by stabilizing membranes, restricting excessive Na+ accumulation, preserving K+ retention, and buffering cellular redox conditions. Externally, Si application can alter rhizosphere physicochemical properties, root-associated metabolites, and microbial community assembly. Si-associated enrichment of plant-beneficial microorganisms may contribute to nutrient cycling, ionic and osmotic regulation, redox protection, and plant growth, while microbial metabolites may reciprocally influence plant signaling and metabolism. Nevertheless, most microbiome functions remain inferred from community profiles and correlations, and causal validation is currently limited to a small number of experimental systems. Si uptake, transport, and spatial deposition provide the physiological basis for these interconnected responses, but their magnitude depends on plant species, genotype, Si-accumulation capacity, formulation, dose, application route, and stress intensity. This integrated framework identifies Si as a context-dependent modulator of plant–rhizosphere interactions and provides a mechanistic basis for developing precise and sustainable Si-based salinity-management strategies.

Flavonoid remodeling and functional characterization of CrHPPD during salt stress response in Carex rigescens.

Soil salinity severely limits plant growth and productivity. Carex rigescens, a low-maintenance turfgrass species native to China, exhibits remarkable tolerance to abiotic stresses. Previous studies have highlighted the importance of the phenylalanine metabolic pathway in salt stress defense in C. rigescens; however, the specific mechanisms remain poorly understood. To elucidate the downstream metabolic and molecular components of this pathway, we analyzed flavonoid metabolism in two contrasting C. rigescens varieties-salt-sensitive 'Lvping No. 1' and salt-tolerant 'Lvping No. 2'-and functionally characterized the 4-hydroxyphenylpyruvate dioxygenase (CrHPPD) gene. Salt stress altered the abundance of several flavonoid metabolites, including 2'-hydroxygenistein, genistin, kaempferol, taxifolin, myricetin, and eriodictyol, identifying them as candidate salt-responsive metabolites. Naringenin and apigenin showed genotype- and tissue-dependent abundance patterns between the two varieties. We cloned CrHPPD, characterized its encoded protein, and found that CrHPPD-GFP displayed a cell periphery-associated fluorescence pattern in transient expression assays, although precise localization requires marker-based validation. CrHPPD expression was induced by NaCl and ABA, whereas PEG treatment elicited a weaker and more transient response. Furthermore, overexpression of CrHPPD in Arabidopsis thaliana enhanced germination rate, root length, catalase activity, and chlorophyll retention under salt stress, with the chlorophyll effect being most evident in OE6. Collectively, these findings reveal genotype- and tissue-specific flavonoid remodeling in C. rigescens under salt stress and demonstrate that CrHPPD positively contributes to salt tolerance when overexpressed in Arabidopsis. These results suggest that flavonoid metabolism and the HPPD-associated homogentisate/tocopherol antioxidant branch may represent two stress-responsive components of phenylalanine/tyrosine-derived metabolism, although their direct mechanistic connection requires further validation.

Systems-level transcriptomic and physiological adaptation of Bacillus licheniformis BLN313 to selenite stress