Physiology and Molecular Biology of Plants最新文献

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.

Drought stress significantly reduces the crop productivity, including pea (Pisum sativum L.), 'necessitating development of effective strategies to mitigate these losses under changing climatic conditions. This study explores the potential of foliar-applied gibberellic acid (GA₃) and brassinolide (BR), individually and in combination, to enhance the drought resilience in pea plants. A pot experiment was conducted comprising of treatments i.e. T0 (no-stress), T1 (Stress-without foliar application), T2 (0.4% GA₃), T3 (0.002% BR) and T4 (T2 + T3). Results indicated that T4 induced the most pronounced improvement in plant height (50%), leaf area (66.4%), total chlorophyll (41%) and carotenoid contents (89%), pod fresh (57.93%) and dry weight (89%), seeds per pod (41%) with enhanced antioxidant activity (81%) as compared to T1 and T0. Additionally, the seed nutrients including crude protein, crude fibre, and nitrogen free extract were increased by 34.6%, 55.9%, and 15% respectively with T4 as compared to T1. The plants treated with T4, were comparable with control in their morphological and yield indices, exhibiting higher stress tolerance; followed by plants receiving T3 (0.002% BR). Molecular docking analysis further substantiates these findings, revealing strong binding affinities of BR (protein ID: 2PWJ; ΔG = - 6.99) and GA₃ (protein ID: KAI2; ΔG = - 7.31) with stress-relieving proteins. These interactions highlight the synergistic role of GA₃ and BR in enhancing drought tolerance through morphological, physiological and metabolic ameliorations. This study concludes that the combined application of GA₃ and BR effectively mitigates drought stress in P. sativum offering a promising approach to safeguard yield under water-limited conditions.

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Lipoic acid (LA) and 24-epibrassinolide (EBL) are versatile compounds that enhance plant stress tolerance by modulating cellular metabolism, maintaining ion balance, and boosting antioxidant enzyme activity. However, the combined effects of these two compounds in mitigating the adverse impacts of osmotic stress remain unclear. We investigated the effects of exogenous LA (12 µM), EBL (0.1 mg L^-1), and their combination (LA + EBL) on stress parameters (plant dry weight, total chlorophyll, leaf relative water content (LRWC)), oxidative stress markers (thiobarbituric acid-reactive substances, hydrogen peroxide, superoxide, and methylglyoxal), activities of antioxidant and glyoxalase system enzymes and the relative expression levels of the genes coding the enzymes related to these systems in maize seedlings under osmotic stress. The results indicated that exogenous application of LA and EBL combination reduced the level of oxidative stress markers and enhanced the stress parameters, ascorbate and glutathione levels, activities of enzymes acting antioxidant and glyoxalase systems, and their gene expression. The combination of LA and EBL was also found to stimulate gene expression levels related to the photosynthetic process and hormone biosynthesis. The findings of the current study highlighted the synergistic effects of combined LA and EBL in enhancing osmotic stress tolerance in maize seedlings. Overall, the combined application of LA and EBL found to have stronger effect than their individual applications in mitigating osmotic stress. The combined use of these compounds offers promising potential for developing drought-tolerant crops in the agricultural sector.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01620-3.

Saffron (Crocus sativus L.) is a sterile triploid medicinal plant and is the world's most expensive cultivated herb. Its dried red stigmas accumulate important carotenoids, which produce apocarotenoids after oxidative cleavage. Saffron produces important apocarotenoids, crocin, picrocrocin and safranal, that provide color, flavor and aroma to it. To understand the expression pattern and stage specificity of apocarotenoid biosynthesis genes, we performed RNA sequencing at six different stages of stigma development (yellow, orange, red, two days before anthesis, at the day of anthesis and two days after anthesis) using Illumina platform. Differential expression analysis revealed preferential/specific expression of many genes at the different stages of stigma development. Functional annotation identified many genes encoding enzymes involved in different steps of apocarotenoid biosynthesis pathways expressed preferentially at red and later stages of stigma development. In addition, gene ontology enrichment analysis revealed several genes involved in primary/secondary metabolic processes and reproductive development pathways, exhibiting higher transcript abundance at the later stages of stigma development. Overall, the data and results presented in this study can serve as a rich resource for understanding the apocarotenoid biosynthesis in C. sativus during stigma development.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01621-2.

Rhizome yield traits and curcuminoids in turmeric (Curcuma longa L.) rhizome are the major determining factors for its production, especially under water-limited environments. Chitosan, a member of biostimulants, regulates physiological adaptation strategy and works as a chemical elicitor in several plant species under withholding water. The objective of the present study was to assess growth characteristics, physiological adaptation, rhizome attributes, total curcuminoids content, and upregulated expression levels of curcuminoids-related genes in turmeric under water withholding using chitosan biostimulant. The response of two contrasting genotypes, high curcuminoids cv. Surat Thani (ST) and low curcuminoids cv. Pichit (PJT) was evaluated under two water management practices (withholding water for 45 days [WD] and daily irrigation/well-watered [WW] condition) with or without foliar application of chitosan at 20 mg L^-1. Leaf area and pseudostem dry weight in ST grown under WD were significantly decreased by 39% and 26%, respectively, over WW condition without chitosan application, whereas the two water management practices resulted in similar responses in plants treated with 20 mg L^-1 chitosan foliar spray. Fresh weight and dry weight of rhizome under WD were decreased by > 40% over WW treatment. Leaf temperature and crop water stress index were sustained at a low level by 20 mg L^-1 chitosan application, resulting in the preservation of leaf osmotic potential and photon yield of PSII, especially in PJT. In contrast, gas exchange parameters such as transpiration rate, net photosynthetic rate, and stomatal conductance were severely affected by WD, which in turn reduced the amount of total soluble sugar. Under WD, the expression levels of curcuminoids-related genes were increased, whereas total curcuminoids content in the turmeric rhizomes was significantly decreased. The results indicate that foliar application of chitosan as a biostimulant plays a positive role in reducing the harmful impact of drought stress and improving growth characteristics; however, the degree of positive effect is dependent on genotype, application dose, and level of water availability.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01618-x.

Pumpkin (Cucurbita moschata Duchesne ex. Poir) is susceptible to various viral infections which significantly hinder its production, impacting agricultural sustainability and food security. The susceptibility of fifty four pumpkin genotypes to squash leaf curl China virus (SLCCNV) and cucurbit chlorotic yellows virus (CCYV) was assessed over two consecutive seasons (2021 rainy and 2022 spring-summer) and in 2023 (spring-summer), specifically for only SLCCNV, through screening in an insect-proof net house under whitefly inoculation conditions. Disease progression was evaluated through the vulnerability index (VI) and the area under the disease progress curve (AUDPC). During 2021 and 2022, on the basis of challenge inoculation studies, highly resistant genotypes (DPU-41, DPU-43, DPU-133, and DPU-105) consistently presented no symptoms and no PCR amplification of SLCCNV or CCYV. Furthermore, during 2023, four genotypes (DPU-41, DPU-43, DPU-133 and DPU-105) presented high resistance levels (VI = 0) to SLCCNV. VI and AUDPC exhibited a significant positive correlation (> 0.96) for whitefly-mediated inoculation screening during 2021 and 2022. Quantitative polymerase chain reaction (qPCR) analysis revealed no detectable SLCCNV load in the highly resistant (DPU-41, DPU-43, DPU-133, and DPU-105) and resistant (DPU-101, and DPU-129) genotypes, with cycle threshold (Ct) values indicating the absence of the virus. Furthermore, inheritance studies involving susceptible and resistant genotypes across six generations (P₁, P₂, F₁, F₂, B₁, B₂) revealed a single dominant gene governing resistance to SLCCNV in the DPU-41 and DPU-43 genotypes. The present findings are the first to reveal the single dominant gene inheritance of resistance to SLCCNV in pumpkin. This study contributes to understanding resistance in pumpkin genotypes against SLCCNV and CCYV, offering a foundation for breeding programs focused on producing resistant varieties.

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Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01613-2.