It is demonstrated that the conserved sulfate starvation transcriptional response across Arabidopsis, tomato, rice, and Setaria is limited to only seven genes, and these findings indicate that the S starvation response is deeply embedded within primary plant metabolism.
Abstract
SUMMARY Mineral nutrients are essential for plant growth and development. Sulfur (S), as a macronutrient, is incorporated into numerous critical S‐containing metabolites that play key roles in mitigating both abiotic and biotic stresses. Understanding how plants regulate S homeostasis and integrate it with other physiological processes is crucial for developing crops that can better withstand environmental challenges. Here, we demonstrate that the conserved sulfate starvation transcriptional response across Arabidopsis, tomato, rice, and Setaria is limited to only seven genes. We further characterize the roles of two of these genes, PYD4 (PYRIMIDINE 4) and MGL (METHIONINE GAMMA‐LYASE), in S metabolite regulation and the sulfate starvation response. Our genetic and biochemical analyses show that PYD4 is embedded within the S starvation network, positively regulating transcript levels of key S‐marker genes, including four of the seven conserved genes across these species, and serving as an integrator of S metabolism and photorespiration. MGL also positively regulates S‐marker genes, while additionally modulating diverse processes under sulfate starvation, such as photosynthesis and oxidoreductase homeostasis. Notably, MGL‐deficient lines fail to respond adequately to sulfate starvation and exhibit impaired mechanisms for maintaining photosynthetic efficiency. Overall, our findings indicate that the S starvation response is deeply embedded within primary plant metabolism. Disruption of its regulators alters metabolism at multiple levels, affecting traits central to crop improvement, such as photorespiration and photosynthesis.
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.
F. Rauf, Hakim Zamir, Hussam Ahmad et al.· Molecular Biotechnology· 0 citations
Improved understanding of how sulfate transport systems function in halophytes is improved and provides a foundation for future research on sulfur-mediated stress tolerance in plants.
Yingyi Yu, Ming-Hua Luo, Yan Leng et al.· Biology· 0 citations
A review of WD40 repeat proteins strengthens current findings relating their structural properties, molecular mechanisms, and functional diversity, underscoring their potential as targets for developing stress-resilient, high-yield crops in a changing climate.
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.
L. Buzzicotti, Claudia Camilletti, L. Ravazzolo et al.· Physiologia Plantarum : An I...· 0 citations
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.
Phosphorus (P) is essential for plant growth and development. Although soils contain abundant total P, about 70% of global arable land is deficient in available inorganic phosphate (Pi), severely restricting sustainable agricultural production. To date, numerous physiological and molecular mechanisms underlying plant adaptation to low-Pi stress have been elucidated. In this review, we provide an overview of recent advances in plant adaptation to low-Pi stress at both the physiological and molecular levels, including root plasticity and hormonal regulation, root exudate-mediated Pi acquisition, metabolic adaptation such as sugar metabolism, membrane lipid remodeling, and secondary metabolite accumulation, as well as arbuscular mycorrhizal (AM) symbiosis. Furthermore, we summarize the molecular regulatory networks governing plant responses to low-Pi stress, covering phosphate transporters, SPX-PHR signaling, transcription factors, non-coding RNAs, and epigenetic modifications. The interaction between low-Pi signaling and other signaling pathways is also discussed. This review synthesizes recent advances in adaptive mechanisms across multiple regulatory levels and discusses strategies for breeding P-efficient crops to support sustainable agriculture.
Junhao Zhang, Ao Pan, Zhangqiang Song et al.· Frontiers in Plant Science· 0 citations
