Cadmium (Cd) pollution leads to reduced crop yields and poses a threat to human health, making it an important environmental and agricultural safety issue. Selenium [Se(V)] has been shown to alleviate Cd stress in plants; however, the mechanisms underlying Se-mediated protection against Cd toxicity remain largely unclear. In this study, we investigated the physiological and molecular mechanisms of Se(W)-alleviated Cd toxicity in strawberry plants through physio-biochemical and transcriptomic analyses. Our results showed that foliar spraying with Se (IV) increased photosynthetic efficiency, reduced Cd-induced oxidative damage by enhancing antioxidant enzyme activities and soluble sugar contents, thereby improving Cd stress tolerance. Transcriptomic profiling revealed 477 common differentially accumulated transcripts (DATs), predominantly enriched in transporter activity, oxidoreductase function, and antioxidant-related processes. Notably, seven key genes involved in Cd efflux, chelation, secondary metabolite transport and nutrient uptake (FvPCR9-like, FvCBP-like, FvWATI-like, FvMOT1, FvY1476gO214O, FvNR12.1 and FvZIP8) exhibited opposite expression patterns under Se(W) and Cd treatments. Supplementation with Se(IV) also modulated phytohormone signaling, nitrogen metabolism and carbon metabolism pathways, providing a multi-dimensional approach to mitigating Cd-induced physiological disruptions. This study provides novel insights into Se(IV)-mediated Cd stress adaptation, and offers promising strategies for developing low-Cd-accumulating crops, addressing critical environmental and agricultural challenges associated with heavy metal contamination.

Greening immediately after etiolated- seedling's emergence from the soil is critical for plants to initiate their autotrophic life cycle through photosynthesis. The greening process relies on a complex transcriptional network that fine- tunes the biosynthesis of chlorophyll and prevents premature development of chloroplasts. In this study, we identified the Arabidopsis HOOKLESS1 (HLS1) as a key regulator of light- induced cotyledon greening. Our results demonstrated that HLS1 is essential for the proper expression of greening- related genes controlling chlorophyll biosynthesis and chloroplast development. Loss of HLS1 severely disrupts the Pchlide- to- Chlide transition and impairs reactive oxygen species (ROS) scavenging in etiolated seedlings upon light exposure, leading to catastrophic ROS burst and even photobleaching. Biochemical assays revealed that HLS1 is a histone acetyltransferase mediating the deposition of H3K9ac and H3K27ac marks at multiple greening- related genes, thereby promoting their transcriptional activation. Genetic analysis further confirmed that HLS1's promotive effect on the greening process is fully dependent on its histone acetyltransferase activity. Moreover, the loss of HLS1 also interrupts the promotive effect of ethylene signaling on the greening process by reducing the binding of ETHYLENE- INSENSITIVE 3 to the promoter region of POR genes, thus inhibiting the activation effect of ethylene signaling on the expression of PORs. Collectively, our study reveals that HLS1 acetylates histones to activate greening- related genes, optimizing chlorophyll biosynthesis and chloroplast development during dark- to- light transition in seedlings.

Among various abiotic stresses, secondary soil salinization poses a significant threat to plant productivity and survival. Cultivated chrysanthemums (Chrysanthemum morifolium), widely grown as ornamental crops, are highly susceptible to salt stress, and their complex polyploid genome complicates the identification of stress resistance genes. In contrast, C. indicum, a native diploid species with robust stress tolerance, serves as a valuable genetic resource for uncovering stress-responsive genes and improving the resilience of ornamental chrysanthemum cultivars. In this study, we cloned, overexpressed (OE-CiHY5), and silenced (RNAi-CiHY5) the CiHY5 gene in C. indicum. OE-CiHY5 plants exhibited larger leaves, sturdier stalks, and higher chlorophyll content compared to wild-type plants, while RNAi-CiHY5 plants displayed weaker growth. Under salt stress, OE-CiHY5 plants demonstrated significantly improved growth, enhanced osmotic adjustment, and effective ROS scavenging. In contrast, RNAi-CiHY5 plants were more sensitive to salinity, showing higher electrolyte leakage and impaired osmotic regulation. Transcriptomic analyses revealed that CiHY5 regulates key hormonal pathways such as zeatin (one of cytokinins), abscisic acid and jasmonic acid, as well as metabolic pathways, including photosynthesis, carbohydrate metabolism, which collectively contribute to the enhanced stress resilience of OE-CiHY5 plants. Promoter-binding assays further confirmed that CiHY5 directly interacts with the CiABF3 promoter, highlighting its critical role in ABA signaling. Evolutionary analyses showed that HY5 is conserved across plant lineages, from early algae to advanced angiosperms, with consistent responsiveness to salt and other abiotic stresses in multiple Chrysanthemum species. These findings establish CiHY5 as a key regulator of salt tolerance in C. indicum, orchestrating a complex network of hormonal and metabolic pathways to mitigate salinity-induced damage. Given the conserved nature of HY5 and its responsiveness to various stresses, HY5 gene provides valuable insights into the molecular mechanisms underlying stress adaptation and represents a promising genetic target for enhancing salt stress resilience in chrysanthemums.

Germinating seeds undergo elaborate de-etiolation developmental transitions upon initial soil emergence. As central transcription factors promoting cotyledon greening, the abundance of ETHYLENE-INSENSITIVE 3 (EIN3) and PHYTOCHROME-INTERACTING FACTOR 3 (PIF3) are strictly controlled by physically associating themselves with the EIN3-BINDING F BOX PROTEINS 1 and 2 (EBF1/2) for ubiquitination. Here, we report that the B-box zinc-finger protein BBX32, as a positive regulator during seedling de-etiolation. BBX32 is robustly elevated during the dark-to-light transitions. Constitutively expressing BBX32 ultimately protects against severe photobleaching damage by synchronizing the accumulation of protochlorophyllide (Pchlide) and the differentiation of etioplast-chloroplast apparatus in buried seedlings. Specifically, BBX32 directly interacts with EIN3, PIF3 and EBF1/2. These associations disrupt the assembly of the SCFEBF1/2-EIN3/PIF3 E3 ligation protein complexes, thus dampening E3 ligase activity and robustly controlling EIN3/PIF3 stability. Under soil conditions, BBX32-ox largely rescues the greening deficiency of EBF1ox, and all EIN3ox/bbx32 seedlings override the bbx32 mutant defect and successfully turn green. Both biochemical findings and genetic evidence reveal a novel regulatory paradigm by which the B-box protein dampens the E3 ligase binding activity to achieve green seedlings upon changes in light or soil environmental conditions.

Salt accumulation can degrade soil properties, decrease its productivity, and harm its ecological functions. Introducing salt-tolerant plant species associated with arbuscular mycorrhizal fungi (AMF) can act as an effective biological method for restoring salinized soils. AMF colonize plant roots and improve their nutrient acquisition capacity. However, there is limited knowledge on how AMF affects the production of signaling molecules, e.g., abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA), related to plant-microbe interactions under salinity. Here, we assess the potential benefits of the AMF Rhizophagus intraradices in enhancing plant growth and nutrient uptake in addition to modulating stress hormone signaling levels (ABA, SA, and JA) of the facultative halophyte Sulla carnosa under saline conditions. Plants were grown in pots filled with soil and irrigated with 200 mM NaCl for 1 month. AMF symbiosis substantially increased the shoot dry weight (+107%), root dry weight (+67%), photosynthetic pigment content (chlorophyll a, chlorophyll b, and carotenoids), and nutrient uptake (C, N, P, K, Cu, and Zn) while significantly limiting the increase in the shoot Na+ concentration and H2O2 content caused by salinity stress. Mycorrhizal symbiosis significantly enhanced the root and shoot SA levels by 450% and 32%, respectively, compared to the stressed non-inoculated plants, potentially contributing to enhanced systemic resistance and osmotic adjustment under saline conditions. Salt stress increased the shoot ABA content, especially in R. intraradices-inoculated plants (113% higher than in stressed non-mycorrhizal plants). These findings confirm that AMF mitigated the adverse effects of salinity on S. carnosa by increasing the SA and ABA levels and reducing oxidative damage.

Soil salinity presents a dual challenge for plants, involving both osmotic and ionic stress. In response, plants deploy distinct yet interconnected mechanisms to cope with these facets of salinity stress. In this investigation, we observed a substantial overlap in the salt (NaCl)- induced transcriptional responses of Arabidopsis roots with those triggered by osmotic stress or the plant stress hormone abscisic acid (ABA), as anticipated. Notably, a specific cluster of genes responded uniquely to sodium (Na+) ions and are not regulated by the known monovalent cation sensing mechanism MOCA1. Surprisingly, expression of sodium- induced genes exhibited a negative correlation with the ABA response and preceded the activation of genes induced by the osmotic stress component of salt. Elevated exogenous ABA levels resulted in the complete abolition of sodium- induced longed sodium- induced gene expression, coupled with increased root cell damage and root swelling under high salinity conditions. Moreover, ABA biosynthesis and signaling mutants were unable to redirect root growth to avoid high sodium concentrations and had increased sodium accumulation in the shoot. In summary, our findings unveil an by salinity stress and modulating sodium- induced responses in plant roots.

In the arid and semi-arid zones of Northwest China, soil drought and alkaline salt stress often occur simultaneously and affect plant growth at multiple levels. Potato (Solanum tuberosum L.) is a food crop sensitive to drought and alkaline salt stresses and is susceptible to yield loss due to environmental impacts. In recent years, most of the research on abiotic stress response in potato has focused on drought and saline single stresses, and the mechanism of potato response to combined drought-alkaline salt stress and its interactions are still unclear. Therefore, a pot experiment was designed in this study and the potato variety 'Atlantic' was selected as the test material. The effects of drought (25 % PEG-6000), alkaline salt (200 mmol & sdot;L-1 NaHCO3) and combined drought- alkaline salt (25 % PEG-6000 + 200 mmol & sdot;L-1 NaHCO3) stresses on growth traits, micro- and ultrastructure, reactive oxygen species, osmoregulatory substances, and antioxidant defenses of potato were investigated using no stress (CK) as a control, leaf photosynthesis and endogenous plant hormones, and also analyzed the changes in the expression patterns of genes related to plant hormone signal transduction under different stresses. The results showed that drought, alkaline salt, and combined stress affected growth, leaf anatomy, and photosynthesis, and increased the accumulation of osmoregulatory substances in potato. The scavenging activities of antioxidant compounds and antioxidant enzymes were enhanced in potato, and combined stress treatments significantly damaged potato more than single stresses. In 2022, combined stress caused a marked increase in H2O2 (208.7 %) and O2- (455.6 %) content, while in 2023, they increased by 87.5 % and 215.7 %, respectively. SOD, POD, CAT, TPX, APX, GR, GPX and DHAR enzyme activities were increased by 209.13 %, 55.19 %, 152.59 %, 47.13 %, 104.02 %, 347.37 %, 68.45 % and 130.69 % in 2022 compared to CK in the combined stress treatment. In 2023, they increased by 229.81 %, 49.95 %, 160.62 %, 102.16 %, 94.06 %, 505.15 %, 47.00 %, and 121.19 %, respectively. After the stress treatments, the contents of gibberellic acid (GA3) and auxins (IAA) were significantly lower than those in CK, whereas the contents of abscisic acid (ABA), salicylic acid (SA), and brassinosteroids (BRs) increased. Expression of IAA-related genes (AUX1, Aux/IAA, GH3, and SAUR) was up-regulated after stress. ABA-related genes (PYR/PYL, SnRK2, and ABF) were up-regulated after stress, whereas protein phosphatase 2C (PP2C) genes were down-regulated in expression after stress. The GA3 receptor GID1 and the Fbox protein GID2 were up-regulated after stress. Xyloglucosyl transferase TCH4 gene was up-regulated by stress and positively correlated with changes in BRs content. The TGA transcription factor, PR-1 gene, was induced to up-regulate its expression by stress and positively correlated with changes in SA content. Drought, alkaline salt, and combined stress reduced potato tuber yield and quality, which were 54.13 % and 60.14 % lower than CK in combined stress treatments in 2022 and 2023, respectively, which were significantly correlated with changes in physiological and biochemical characteristics and hormone contents of potato plants.

Fluoride, a naturally occurring element found in water, soil, food, and atmospheric precipitation, can lead to fluorosis and various health issues when consumed excessively. However, the mechanism of fluorosis is still under investigation. This study utilizes Caenorhabditis elegans as a model organism to investigate the effects of fluoride exposure on biological systems and to explore the mechanisms by which curcumin mitigates fluoride- induced toxicity. Three groups were established: a blank control, a sodium fluoride (NaF) exposure group (concentration 5 mmol/L), and a curcumin intervention group (concentration 25 mu mol/L). Physiological parameters, lipofuscin levels, intracellular reactive oxygen species (ROS) levels, mitochondrial membrane potential, and mitochondrial copy numbers were measured to assess the effects of fluoride toxicity and curcumin protection. RNA-seq and qRT-PCR were utilized to investigate the molecular mechanisms underlying fluoride- induced damage and curcumin's mitigating effects. Results indicated that fluoride-exposed nematodes displayed physiological abnormalities, increased ROS production, higher lipofuscin levels, altered mitochondrial membrane potential and mitochondrial copy number, and activated MAPK signaling pathway genes. Curcumin exhibited protective effects on these parameters, suggesting its potential in preventing fluoride-induced harm by modulating oxidative stress and preserving mitochondrial function. This research enhances our understanding of the mechanisms of fluoride toxicity and highlights the potential benefits of curcumin.

Plant growth and productivity are continually being challenged by a diverse array of abiotic stresses, including: water scarcity, extreme temperatures, heavy metal exposure, and soil salinity. A common theme in these stresses is the overproduction of reactive oxygen species (ROS), which disrupts cellular redox homeostasis causing oxidative damage. Ascorbic acid (AsA), commonly known as vitamin C, is an essential nutrient for humans, and also plays a crucial role in the plant kingdom. AsA is synthesized by plants through the d-mannose/l-galactose pathway that functions as a powerful antioxidant and protects plant cells from ROS generated during photosynthesis. AsA controls several key physiological processes, including: photosynthesis, respiration, and carbohydrate metabolism, either by acting as a co-factor for metabolic enzymes or by regulating cellular redox-status. AsA's multi-functionality uniquely positions it to integrate and recalibrate redox-responsive transcriptional/metabolic circuits and essential biological processes, in accordance to developmental and environmental cues. In recognition of this, we present a systematic overview of current evidence highlighting AsA as a central metabolite-switch in plants. Further, a comprehensive overview of genetic manipulation of genes involved in AsA metabolism has been provided along with the bottlenecks and future research directions, that could serve as a framework for designing stress-smart crops in future.

Plants respond to complex blends of above- and below-ground volatile organic compounds (VOCs) emitted by neighboring plants. These responses often involve priming (i.e., preparation) or induction (i.e., increase) of defenses by receiver plants upon exposure to VOCs released by herbivore-damaged neighboring emitters. However, recent work has shown that induction of VOC emissions by herbivory is modulated by abiotic factors, potentially affecting plant-plant signaling. We tested the effect of soil salinization on the induction of VOC emissions in wild cotton (Gossypium hirsutum) due to leaf damage and its consequences for the induction of defenses in neighboring plants. To this end, we performed a greenhouse factorial experiment where emitter plants were subjected to augmented soil salinity (vs. ambient salinity) and within each group emitter plants were subsequently exposed to simulated caterpillar damage (mechanical leaf damage treated with Spodoptera frugiperda oral secretion) or no damage (control). After 48 h of exposure, we collected VOCs released by emitter plants and then damaged the receivers and collected their leaves to measure levels of chemical defenses (terpenoid aldehydes of known insecticidal effects). We found an interaction between leaf damage and salinization for two groups of VOCs released by emitters (sesquiterpenes and other aromatic compounds), whereby damaged receivers had higher emissions than control plants under ambient but not salinized soil conditions. We also found that, upon being damaged, receiver plants exposed to damaged emitters exhibited a significantly higher concentration of heliocides (but not gossypol) than control plants. However, salinization did not alter this VOC exposure effect on receiver induced responses to damage. Overall, we show that exposure to induced VOC emissions from damaged plants magnifies the induction of chemical defenses due to leaf damage in neighboring individuals and that this is not contingent on the level of soil salinity despite the latter's effect on VOC induction.