Physiologia plantarum最新文献

Plants are constantly exposed to sound vibrations (SVs) from different sources, which have a significant impact on their growth and adaptation. However, how plants perceive and respond to SVs remains largely unknown. In this study, we examined the early biochemical signaling events, like reactive oxygen species (ROS) and hormonal dynamics, in Arabidopsis after 30 and 60 min of specific single-frequency SV treatments (500 Hz, 100 dB). Our results showed that SV triggers ROS production after 30 and 60 min treatment as compared to non-SV treatment plants. To further confirm, we evaluated the transcript levels of 10 respiratory burst oxidase homologs (RBOHs) in Arabidopsis after SV treatment. Our results showed that SV treatment significantly increased the expression of RBOHA, RBOHD, and RBOHF, while SV downregulates RBOHE, RBOHG, RBOHH, and RBOHJ at both time points. However, SVs have no effect on the transcript of RBOHC and RBOHI at both time points. Further, we examine the effect of SVs on plant hormones like salicylic acid (SA), jasmonic acid (JA), abscisic acid (ABA), auxin (AUX), gibberellic acid (GA), cytokinin (CY), and brassinosteroid (BR), and their marker genes. Based on the LC-MS/MS quantification assay and real-time PCR analysis, SV treatment increases SA, JA, CY, and GA levels while decreasing ABA, IAA, and BR. These results revealed that SV mechanosignals trigger early biochemical signaling events like ROS and hormones, which can regulate subsequent key signaling cascades involved in SV signal transduction.

Chicory roots produce inulin, a dietary fiber, as well as large quantities of bitter sesquiterpene lactones (STLs), which have valuable biological activities. In an effort to understand the compartmentalization of metabolism within chicory roots and the molecular basis of the development of laticifers that produce the chicory latex, we performed metabolomics and transcriptomics profiling of different tissues of chicory roots. Gas chromatography coupled to mass spectrometry (GC-MS) and liquid chromatography coupled to mass spectrometry (LC-MS) identified a total of 21,437 features, of which 135 were differentially abundant between cell types. Further analysis indicated that the major STLs accumulated primarily in the latex. Gene expression of known STL pathway genes indicates a compartmentalization of the biosynthesis across multiple tissues, with implications regarding the trafficking of pathway intermediates. Phytohormone measurements and gene expression analysis point to a major role for jasmonate signaling in the development and differentiation of laticifers. Furthermore, inulin accumulates mostly outside the laticifers, but expression of inulin metabolic genes also points to a complex distribution and trafficking of inulin or inulin precursors across different root compartments. Altogether, the data presented here constitute a unique resource to investigate several biological processes in chicory roots, including laticifer development, STL biosynthesis and transport, and inulin biosynthesis regulation.

The temperature increase caused by climate change induces the accumulation of misfolded proteins in the endoplasmic reticulum. To restore protein homeostasis, plants activate the Unfolded Protein Response (UPR). In this study, the involvement of UPR in improving severe heat stress tolerance through molecular priming was explored in Triticum aestivum. The UPR activation and turn-off dynamics were determined. Moreover, the importance of the TaIRE1/TabZIP60 induction branch in the response to ER stress was assessed using TaIRE1 knockout mutants. The results indicate that plants primed with dithiothreitol exhibit a faster and higher TabZIP60 splicing response to temperature stress than unprimed plants. This suggests that UPR induction by TaIRE1/TabZIP60 is a finely regulated adaptive mechanism that alleviates the ER stress caused by heat increase. Moreover, UPR was defined as a molecular primer insofar as it participates in enhancing the stress response. Furthermore, the development and photosynthetic capacity of TaIRE1 mutants were negatively affected, resulting in increased cellular damage in response to ER stress. The TaIRE1/TabZIP60 induction branch, crucial for ER stress recovery, does not appear to be fully compensated by TabZIP28. This study provides new insights into the role of the UPR in response to abiotic stresses and proposes potential strategies to improve wheat heat tolerance.

Experimental evidence on the antioxidant role of arbutin, the main phenolic constituent in pear trees, remains limited. In this study, we investigated the effect of exogenous arbutin on the resistance of pear leaves to methyl viologen (MV)-induced oxidative stress. The results showed that arbutin application alleviated chlorophyll degradation and maintained higher photosynthetic efficiency under MV stress. Exogenous arbutin also attenuated the accumulation of malondialdehyde and H₂O₂ and promoted the activity of antioxidant enzymes. Additionally, exogenous arbutin had a mitigating effect on the MV-induced decline in phenolic accumulation and antioxidant capacity, as demonstrated by DPPH and FRAP assays. The expression of phenolic and arbutin biosynthesis-related genes (PAL, CHS, and UGT) significantly increased after MV exposure. Furthermore, arbutin-pretreated pear calli exhibited enhanced tolerance to cold, salt, and abscisic acid (ABA) stresses, characterized by elevated antioxidant enzyme activity and decreased oxidant levels. In tobacco leaves, transient overexpression of UGT enhanced arbutin accumulation and alleviated MV-induced oxidative damage. Collectively, these findings highlight the function of arbutin in controlling oxidative stress responses in pear leaves.

Ultraviolet-B (UV-B) radiation is an intrinsic component of the solar spectrum that acts as an environmental cue, exerting a strong influence on plant physiology, morphology, and environmental acclimation. UV RESISTANCE LOCUS 8 (UVR8) is recognized as the sole specific UV-B photoreceptor, mediating perception and initiating a sophisticated signaling cascade that facilitates developmental and protective responses. UV-B irradiation triggers the dissociation of the cytosolic UVR8 homodimer into biologically active monomers. This structural transition enables rapid, regulated nuclear translocation, where the UVR8 monomer interacts with the E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1). This interaction, involving a critical two-interface binding mechanism, inhibits COP1 activity toward key transcription factors, notably ELONGATED HYPOCOTYL 5 (HY5), thereby stabilizing them and orchestrating the UV-B acclimation transcriptome. Furthermore, UVR8 functions as a crucial hub for signaling integration, directly modulating multiple phytohormone pathways, coordinating spectral responses with other photoreceptors, and regulating novel non-canonical modules in both the nucleus and the cytoplasm. This comprehensive review examines the molecular architecture, photocycle dynamics, integrated signaling mechanisms, and critical physiological roles of UVR8. Finally, we provide perspectives on unresolved questions concerning its full array of post-translational modifications and the potential to apply this knowledge to enhance crop resilience.

Drought is one of the most critical abiotic stresses limiting global crop productivity, and nanoparticles (NPs) have recently emerged as promising tools to enhance plant stress tolerance. However, how strongly and in what ways NPs influence plant performance is not yet well established, particularly in relation to drought intensity and nanoparticle identity. We conducted a comprehensive meta-analysis of studies assessing physiological and biochemical traits, comparing plant responses with and without nanoparticle application under well-watered, moderate, and severe drought conditions, and identifying particle-specific effects through subgroup analyses. The results revealed that application of NPs consistently improved plant performance in a stress-dependent manner. Chlorophyll content effect size increased up to 44% under moderate drought, while oxidative stress markers (MDA, H₂O₂) declined more than twofold under both moderate and severe drought. Under severe drought, nanoparticles markedly enhanced antioxidant activities: CAT, SOD, and POD effect size increased by about 30%-35% relative to controls. Particle-specific responses evidenced that titanium NPs produced the highest yield gains (effect size = 11.1), whereas iron-based NPs had negligible effects. Under well-watered conditions, titanium, zinc, and silicon-based NPs promoted chlorophyll accumulation and yield stability. Under moderate drought, zinc, silicon, and selenium-based NPs improved yield and pigments, while titanium NPs supported osmotic balance. Under severe drought, copper, cerium, and titanium-based NPs showed strong osmotic and enzymatic protection. Overall, this meta-analysis shows that NPs improved plant performance across both optimal and drought conditions, with responses varying according to drought severity and nanoparticle identity.

Elevated temperatures severely disrupt pollen function, posing a major threat to agricultural productivity. While research into pollen thermotolerance is rapidly expanding, the quest to identify and develop heat-tolerant crops is challenged by a lack of consistent methodological considerations and experimental design principles. This review critically examines the experimental pipeline for assessing pollen quality and function under heat stress conditions, pinpointing where methodological variability most affects data reliability and comparability. We emphasize that accurate assessment begins with a careful experimental design, including the selection of appropriate methods to test thermotolerance, precise staging of pollen development, and effective sampling strategies to ensure comparable pollen populations. We then detail how different thermal stress parameters, such as duration, intensity, and timing, should be appropriately applied to accurately capture physiological responses, including the induction of thermotolerance. Finally, we provide a structured overview of current phenotypic and molecular assays, emphasizing the importance of high-throughput techniques in uncovering underlying mechanisms of pollen thermotolerance. By offering clear guidance and recommendations at each stage, from experimental setup to data analysis, this review offers a consistent and rigorous approach to pollen heat stress studies, aiming at enhancing the reproducibility and impact of future discoveries in this vital field.

The labellum, a distinctive floral organ unique to orchids, possesses significant ornamental and research value. Here, wild type plants (W1, W2), a lip-like sepal mutant (MS), a lip-like petal mutant (MP), and a peloric flower mutant (ML) of Cymbidium ensifolium were used to elucidate the molecular mechanisms underlying labellum formation. Morphological and cytological analyses revealed that MS sepals and MP petals acquired labellum-like traits (folded structures, conical papillae), whereas ML labella adopted petal-like features (flat epidermal cells). Transcriptome analysis identified seven key B- and E-class MADS-box genes (including DEF-/AP3-, SEP-, and AGL6-like genes) potentially involved in labellum development. Subsequent qRT-PCR profiling showed that gene expression dynamics closely reflect organ fate. Expression of CeAP3-3 and CeAP3-4 correlated with the establishment of inner perianth identity (petal/labellum), while CeAGL6-2 activation was specifically associated with labellum specification. Notably, CeAGL6-2 was ectopically expressed in lip-like organs of MS and MP, but absent in the petaloid labellum of ML. Conversely, expression patterns of CeAP3-1 and CeAGL6-1 suggested roles in promoting sepal/petal or non-labellum perianth fates. Protein interaction assays (Y2H, BiFC) demonstrated that CeAP3-3 interacted strongly with CeAGL6-2 and CeSEP2, while CeAP3-4 interacted with CeSEP2. Integrating these results, we propose a model in which heteromeric complexes formed by CeAP3-3, CeAGL6-2, and CeSEP2 are central to specifying labellum identity in C. ensifolium. Overall, these findings highlight the cooperative role of B- and E-class transcription factors in labellum specification through dynamic expression shifts and protein interaction networks, thereby enriching our understanding of the molecular mechanisms driving orchid labellum formation.

Aluminum toxicity is a major problem for the growth of plants in acidic soils. Plant growth-promoting rhizobacteria such as Bacillus toyonensis Bt04 offer promising solutions to alleviate such stress through hormonal modulation and improved stress tolerance. This study investigated the ability of Bt04 to mitigate aluminum toxicity in maize roots and its interaction with auxin transport. Efflux inhibitor 1-N-naphthylphthalamic acid (NPA) and influx inhibitor 1-naphthoxyacetic acid (1-NOA) were applied to assess their effects on stress phytohormone dynamics and aluminum accumulation. Bt04 inoculation reduced aluminum accumulation in root tissues, particularly in the transition zone, which is consistent with the improvement of root barrier functions or exclusion mechanisms. Hormone profiling revealed that Bt04 produced significant quantities of salicylic and benzoic acid (3000 and 15,430 pmol g^-1DW, respectively), while abscisic acid (ABA) and jasmonic acid (JA) productions were low. Auxin transport modulation showed distinct effects on root hormone profiles. NPA suppressed ABA level, whereas 1-NOA enhanced its accumulation by 124% under stress. Bt04 amplified or reversed these effects depending on the type of co-treatment, highlighting its regulatory role in hormonal homeostasis. JA levels increased after NPA treatment, reaching 13,323 pmol g^-1DW, but were reduced by 81% when Bt04 was co-applied. Bt04 together with 1-NOA increased JA and JA-Ile under stress, respectively by 81% and 159%, indicating a stress-specific synergy. These results demonstrate that Bt04 mitigates aluminum toxicity by modulating hormonal crosstalk and auxin transport, making it a potential tool for use in biofertilization strategies to improve crop resilience in acidic, aluminum-affected soils.

The use of Moringa oleifera Lam. extracts (ME) as natural biostimulants has been increasingly recognized as an effective strategy to stimulate plant growth and improve nutrient utilization. In this study, alcoholic (ME_EtOH), hydroalcoholic (ME_H2O/EtOH), and aqueous (ME_H2O) leaf extracts were compared in terms of their physicochemical and nutritional properties, as determined by elemental analysis and NMR spectroscopy. The foliar bioactivity of these extracts was also evaluated in rice (Oryza sativa L.). The alcoholic extract showed a higher proportion of non-polar compounds and the highest C/N ratio (42:1), whereas the aqueous and hydroalcoholic extracts were richer in polar metabolites and essential minerals. Foliar application revealed distinct physiological responses in rice. The hydroalcoholic extract exhibited the strongest effects, significantly enhancing photosynthetic performance (a 16.8% increase in the chlorophyll a fluorescence performance index), upregulating nitrogen-assimilation genes, and increasing root and shoot biomass (≈approximately 29% higher root fresh weight) and fine-root formation (+25%). The aqueous extract induced slower but sustained improvements, resulting in moderate gains in photosynthetic efficiency and biomass accumulation, while the alcoholic extract showed more limited effects. All extracts increased leaf N, P, and K contents, indicating that growth promotion was driven mainly by physiological stimulation rather than direct nutrient supply. Overall, the results demonstrate that the extraction solvent strongly influences extract composition and bioactivity, with the hydroalcoholic formulation showing the greatest potential to enhance growth, photosynthetic metabolism, and nutrient-use efficiency in rice under greenhouse conditions, warranting further field validation.