Physiology and Molecular Biology of Plants最新文献

Oxidative stress mediated by reactive oxygen species and the concomitant antioxidant defenses orchestrate the senescence trajectory in ethylene-insensitive flowers. This investigation delineates the potential of γ-Aminobutyric acid (GABA) in ameliorating oxidative damage and impeding senescence in detached scapes of Hemerocallis fulva, an ethylene-insensitive flower system. The delayed senescence and enhanced scape performance were attributed to the upregulation of antioxidant enzyme activities, including superoxide dismutase, catalase and ascorbate peroxidase, which were elevated by 52.83%, 129% and 126.07%, respectively. These elevated antioxidant defenses were associated with a significant 41.88% reduction in hydrogen peroxide levels, thereby alleviating oxidative stress. Elevated oxidative stress in the control group was associated with the upregulation of SAG12 (Senescence-Associated Gene 12) and LOX1 (Lipoxygenase 1) gene expression, alongside the downregulation of DAD1 (Defender Against Death 1), indicative of accelerated senescence. Conversely, treatment with 40 µM GABA significantly modulated the expression of these genes, leading to a 1.5-fold upregulation of DAD1 and marked downregulation of SAG12 and LOX1 by 4-fold and 6.5-fold, respectively, relative to the control. GABA-treated scapes also manifested significantly higher concentrations of proline, phenols, sugars and soluble proteins in floral tissues compared to the control. Furthermore, GABA enhanced membrane integrity and curtailed bacterial proliferation in vase solutions, thereby optimizing solution uptake by the flowers. Our study concluded that GABA delayed flower scape senescence not only by mitigating oxidative stress through the enhancement of antioxidant enzyme activities but also by modulating senescence-associated gene expression.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01636-9.

Under biotic stress, plant polyamine metabolism undergoes significant changes, including increased biosynthesis and catabolism, which lead to hydrogen peroxide production. However, the roles of polyamine mobilization and transport across membranes remain elusive. Arabidopsis thaliana encodes five Polyamine Uptake Transporters (PUT1-PUT5). In this study, we investigated the role of polyamine transport in Arabidopsis during its interaction with the necrotrophic fungus Botrytis cinerea (Bc). Fungal inoculation induced the expression of all PUT/LAT genes at different times throughout disease progression. To assess their contribution to defense, we challenged five homozygous put mutants (put1-1 to put5-1) with Bc. Notably, put2-1 and put5-1 exhibited increased susceptibility to Bc, which was further exacerbated in the put2-1 put5-1 double mutant. Spermidine supplementation had a reduced effect on enhancing Bc resistance in put mutants, while it increased resistance in the 35S::PUT2 overexpression lines, suggesting that spermidine transport contributes to plant defense. Consistently, spermidine treatment elevated endogenous spermidine levels in WT but had minimal effect on put2-1, put5-1, or the double mutant. In contrast, spermine supplementation raised endogenous spermine levels in all genotypes, even under infection. Under mock conditions, catalase and ascorbate peroxidase activities were elevated in put mutants, while polyamine oxidase activity remained unchanged. These antioxidant enzymes and polyamine oxidase activity were induced upon Bc infection in WT but not in put mutants. Thus, disruptions in polyamine transport may affect their catabolism and the plant antioxidant response. This research emphasizes the importance of PUT-mediated polyamine transport in the plant's defense response to Bc.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01630-1.

Wheat (Triticum aestivum L.) is one of the most important cultivated cereal grain crop. The yield and productivity of wheat are profoundly affected by abiotic stresses like drought. The external surface of wheat plants, including the flag leaf, stem, and spikes, features a visible bluish-grey layer of epicuticular wax, commonly referred to as glaucousness. Cuticular wax accumulation in wheat plants under drought stress plays a crucial role in reducing water loss. Present study was carried out to identify marker trait associations (MTAs) associated with glaucousness in wheat. Phenotyping for glaucousness was conducted for three cropping seasons (2019-2020, 2020-2021 and 2021-2022.) represented as Environment first (E1), Environment second (E2), Environment third (E3), and a combined environment (CE). The diverse wheat association panel was genotyped using 13,006 single-nucleotide polymorphisms (SNPs). Multi-locus genome-wide association study was performed through multi-locus random-SNP-effect mixed linear model (mrMLM) and Bayesian-information and linkage-disequilibrium iteratively nested keyway (BLINK) models. Using the mrMLM and BLINK models, 31 and 34 significant MTAs, respectively were identified. Multiple MTAs were co-localized with previously reported glaucousness related genes/MTAs/QTLs. Interestingly, significant MTAs on the short arm of chromosome 2B were identified where the wax-related genes W1 and W3, known to regulate glaucousness in wheat, have been previously reported. Candidate gene (CG) analysis, lead to the identification of potential CGs with protein domains associated with drought stress. Collectively, the significant MTAs and CGs identified in the present study hold substantial potential for improving glaucousness in wheat through the application of marker-assisted selection (MAS) approach.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01624-z.

Drought stress substantially threatens global food security. To cope with this, a field-based trial was performed to examine the influence of PGPRs/microbial consortia (Cytobacillus firmus & Pseudomonas aeruginosa) and kinetin on the maize under full irrigation and 50% drought. The results of biochemical features of bacteria revealed positive for phosphorus, and zinc solubilization with great capacity to battle stress circumstances owing (ACC deaminase, Indole 3 Acetic acid IAA, and siderophore) production. Seeds treated with the PGPRs consortium along, with a kinetin foliar spray, greatly decreased the consequences of stress from drought on maize and improved yield characteristics, macronutrients, antioxidant enzymes, photosynthetic content production under 50% drought stress. Osmolytes and secondary metabolites were up-regulated under full irrigation when the PGPRs consortium and kinetin were used. When PGPRs and kinetin were combined, the overproduction of malondialdehyde and H₂O₂ was reduced. Water stress decreased oil, kernel sugar, protein, and moisture content in maize cultivars, but increased seed fiber, starch, and ash. PGPRs and kinetin enhanced seed sugar, oil, moisture, protein, ash, and fiber levels in maize grown under well-irrigated and drought-stress environments. Finally, PGPR (10^-7 cfu/mL) and PGR (Kinetin10^-3 M) can be employed together to boost maize production in drought-prone areas.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01629-8.

Sugars are essential for plant development, with nitrogen (N) availability playing a critical role in their distribution across plant organs, ultimately shaping growth patterns. However, the regulatory mechanisms modulating carbon (C) assimilate allocation and utilization under different N forms are not well understood. This study examined C fixation, utilization, and spatial re-distribution in the roots of hydroponically grown maize seedlings subjected to four N treatments: 1 mM NO₃ ^- (low N; LN), 2 mM NO₃ ^- (medium N; MN), 10 mM NO₃ ^- (high N; HN), and 1 mM NH₄ ⁺ (low ammonium; LA). LN treatment significantly increased soluble sugar, sucrose, and starch contents while promoting greater root biomass at the expense of shoot biomass, leading to a higher root to shoot assimilate allocation. The activities of sugar and starch metabolism enzymes were more tightly regulated under LN, indicating enhanced C utilization and increased competition for assimilates. Key genes involved in sugar (ZmSPS, ZmSuSy, ZmSWEET6, ZmSUC2, ZmSTP2, and ZmAINV1) and starch (ZmAGPASE and ZmSS) metabolism were upregulated under LN, correlating with increased root sucrose and starch accumulation and enhanced enzyme activity. Sucrose and starch accumulated predominantly in the brace and lateral roots. This pattern suggests that excess C accumulation results from inefficient C utilization in sink tissues rather than impaired C assimilation. These findings provide new insights into how LN modulates C partitioning in roots for stress adaptation, highlighting the importance of improving C utilization in sink tissues to mitigate N deficiency and enhance plant growth.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01631-0.

Light intensity plays a pivotal role in modulating the development and secondary metabolite production of medicinal plants. This research thoroughly examines the impact of varying light levels (50 [A], 100 [B], 200 [C], 400 [D], and 600 [E] μmol m^-2 s^-1) on Dendrobium denneanum, focusing on its morphological traits, physiological and biochemical responses, and secondary metabolite content. Our findings indicate that an intermediate light intensity of 400 μmol m^-2 s^-1 markedly improves stem diameter, leaf dimensions (length and width), and the synthesis of photosynthetic pigments, including chlorophyll a, chlorophyll b, and carotenoids, with pronounced effects observed during later treatment phases. At 400 μmol m^-2 s^-1, antioxidant enzyme activities (CAT, POD, SOD) reached their highest levels, while malondialdehyde (MDA) levels were the lowest, indicating efficient reactive oxygen species (ROS) scavenging capacity. Soluble sugars and proteins accumulated significantly at 400 μmol m^-2 s^-1, supporting metabolic homeostasis and stress tolerance. Secondary metabolites (flavonoids and polyphenols) peaked at 400 μmol m^-2 s^-1. Principal component analysis (PCA) and resistance contribution diagrams revealed that 400 μmol m^-2 s^-1 achieved the highest composite scores across morphological, physiological, and metabolic indicators. This study not only pinpoints an optimal light condition for maximizing growth, ornamental characteristics, and the yield of valuable medicinal compounds in Dendrobium denneanum but also offers a scientific basis for precise, resource-efficient cultivation. These insights are valuable for enhancing the sustainable production and quality consistency of this and potentially other economically important medicinal and ornamental plants, supporting both the phytopharmaceutical and horticultural industries.

Citrulline (CITR) is a strong osmolyte and hydroxyl radical scavenger. However, no previous study has reported the ameliorative role of CITR under salinity stress. We found a significant decrease in growth, chlorophyll content, SPAD value, photosynthesis, leaf relative water content, and nutrient acquisition in sunflower plants exposed to salinity (15 dS m^‒1). Salinity caused substantial oxidative damage through elevating the levels of superoxide radicals (O₂ ^•‒), hydrogen peroxide (H₂O₂), hydroxyl radicals (·OH), leaf relative membrane permeability, malondialdehyde (MDA) and activity of lipoxygenase (LOX). Plants subjected to salinity manifested a higher buildup of methylglyoxal (MG), further exacerbating the cellular damage. However, CITR seed priming (1, 2, and 3 mM) partially relieved the negative repercussions of salinity by promoting the activities of antioxidant enzymes and levels of non-enzymatic antioxidants. Consequently, plants raised from CITR-primed seeds suffered less from oxidative damage and exhibited lower generation of O₂·^‒, H₂O₂, ·OH, MG, MDA, and activity of LOX. Plants under CITR supplementation exhibited higher chlorophyll content and improved efficiency of photosystem II as evidenced by higher values of maximum efficiency of photosystem-II (Fv/Fm), fraction of open PSII centers (qL), and photochemical quenching coefficient (qP). Citrulline priming enhanced plant resilience under salinity by improving hormonal balance, promoting polyamine accumulation, and sustaining photosynthetic performance. CITR bettered osmotic regulation through increased accumulation of osmolytes such as proline, glycine betaine, and total soluble sugars. Citrulline improved nutrient acquisition and diminished excess Na buildup, preventing specific ion toxicity and osmotic stress.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01626-x.

Aluminum (Al) toxicity is a major impediment to plant growth and yield in low pH soils. Exclusion and/or vacuolar sequestration of Al with organic acids and phenolic compounds is the primary tolerance mechanism utilized by plants to mitigate Al toxicity. However, little is known about the intrinsic and Al-induced metabolic differences underlying intraspecific variability in tolerance to Al toxicity. To fill this gap, we determined root metabolic profiles of Al-sensitive (Golia-99) and Al-tolerant (Demir-2000) bread wheat cultivars treated with 0, 10, and 30 µM AlCl₃·6H₂O using nuclear magnetic resonance (NMR) spectroscopy. Our results showed that there were marked differences in the concentrations of numerous metabolites between Golia-99 and Demir-2000 roots under both control and Al stress conditions. In this regard, a number of metabolites from the amino acid and TCA groups, such as citrate, cysteine, glutamate, isocitrate, phenylalanine, and succinate, were found to be intrinsically higher levels in Demir-2000 than in Golia-99. In addition, Al toxicity led to the accumulation of asparagine, glutamine, putrescine, pyroglutamate, and soluble sugars in Demir-2000 roots. Furthermore, Al treatments significantly altered many metabolic pathways in both cultivar-specific and cultivar-independent manners. The major pathways contributing to the difference in Al toxicity tolerance between Demir-2000 and Golia-99 were arginine biosynthesis, glycolysis/gluconeogenesis, and the metabolisms of cysteine and methionine, glutathione, glycine, serine and threonine, pyruvate, sulfur, and tyrosine. Overall, our results suggest that the distinct patterns of Al-induced overrepresentation in amino acid, carbohydrate, and energy metabolism play an important role in explaining the differential tolerance capacities of Demir-2000 and Golia-99 to Al toxicity. The outcomes of this study may provide valuable insights into improving Al tolerance in wheat through breeding and genetic engineering.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01622-1.

Cytoplasmic Ca²⁺ ([Ca²⁺]_cyt) elevation is a rapid response of roots to colonizing beneficial and pathogenic fungi. We have previously demonstrated that the elicitor-active compound cellotriose from a cell wall (CW) extract of the beneficial fungus Piriformospora indica requires the MALECTIN-DOMAIN CONTAINING CELLOOLIGOMER RECEPTOR KINASE1 (CORK1) and the mitochondrial POLY(A)-SPECIFIC RIBONUCLASE AtPARN for [Ca²⁺]_cyt elevation in Arabidopsis roots. Here, we show that CW extracts from beneficial and pathogenic Fusarium strains, in particular Fusarium incarnatum strain K23, require AtPARN, but not CORK1 for [Ca²⁺]_cyt elevation and the activation of Ca²⁺-dependent downstream responses. [Ca²⁺]_cyt elevation by the F. incarnatum strain K23 extract does not require the BRASSINOSTEROID INSENSITIVE1-ASSOCIATED RECEPTOR KINASE1 (BAK1) co-receptor or the TWO-PORE Ca²⁺ CHANNEL1 (TPC1) but operates synergistically with the cellotriose- and chitin-induced signaling pathways. We propose a convergence of the signaling pathways induced by the CW extracts from P. indica and K23 at AtPARN prior to the increase in [Ca²⁺]_cyt ~ 90 s after the stimulus. Furthermore, the elevated [Ca²⁺]_cyt levels activate a mild defense response which might be used by the roots to restrict fungal propagation and to balance beneficial and non-beneficial traits in the symbiosis.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01600-7.

This study evaluates the potential of green-synthesized curcumin nanoparticles (Cur-NPs) for mitigating arsenic (As) stress in wheat cultivars Barani-70 and NARC-09. Cur-NPs were characterized by UV-visible spectrophotometry, XRD (36 nm), Fourier Transform Infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM), revealing well-dispersed, amorphous structures and functional groups. Both cultivars were subjected to 10 mg/L arsenic stress and treated with Cur-NPs at 50 mg/L and 100 mg/L through soil and foliar applications. Cur-NPs reduced arsenic uptake by up to 65.01% in leaves and 77.32% in roots. Cur-NP treatments lowered MDA by 50% and H₂O₂ by 14%. Antioxidant enzyme activities improved; superoxide dismutase (SOD) increased by 13%, peroxidase (POD) by 5%, and catalase (CAT) by 0.5%. Proline content rose by 47%, enhancing osmoprotection. Chlorophyll a and b increased by 24% and 67%, respectively, while carotenoid content rose by 82%. Agronomic traits improved significantly, with plant height increasing by 69.6%, grain yield by 141.3%, and biomass yield by 1260.9%. Starch and total sugar content increased by 155% and 218%, respectively, while protein content rose by up to 225%. Phenolic and flavonoid contents increased by 43% and 37%, strengthening antioxidant defences. These findings underscore the efficacy of Cur-NPs as a sustainable approach to mitigate arsenic toxicity, strengthen antioxidant defence mechanisms, and enhance both physiological traits and agronomic performance in wheat, offering a strong foundation for future field-scale validation and environmental application.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01615-0.