Plant signaling & behavior最新文献

Oat (Avena sativa L.) is an important forage crop widely used in animal husbandry. However, the greenhouse effect, which leads to increasing global temperatures, extreme water scarcity, and more frequent drought events, also creates abiotic stress that inhibits oat growth. Drought stress strongly affects the yield and quality of forage oats, hindering the selection, promotion, and utilization of drought-resistant cultivars. This study investigated alterations in the growth and physiological traits of diverse oat cultivars under drought stress for varying durations. We comprehensively assessed the drought resistance capabilities of each variety. Forty oat cultivars were subjected to drought stress starting from plant growth up to the two-leaf stage a pot-based water withholding method. The stress durations were 0 d, 7 d, and 14 d. Compared with those of the control, the key physiological parameters of the test cultivar decreased with increasing drought stress duration. These factors increased the maximum photochemical quantum yield (Fv/Fm), PS II quantum efficiency (Fv/Fo), soil plant analysis development (SPAD) value, net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs). Conversely, the malondialdehyde (MDA) and proline (Pro) contents increased. Antioxidant enzyme activity initially increased but subsequently decreased. Changes in osmoregulatory substance content and the modulation of antioxidant enzyme activity are key components of drought resistance mechanisms. Therefore, Fv/Fo, Pro, Tr, Gs, and Pn have emerged as reliable parameters for assessing drought resistance in forage oat seedlings. When assessing seedling drought resistance using biochemical parameters such as photosynthesis, a comprehensive analysis combining multiple indicators and methods is essential. This study provides a theoretical basis for screening drought-resistant oat cultivars and for high-yield cultivation practices.

Root exudates are pivotal mediators of plant-soil interactions, influencing nutrient acquisition, soil structure, microbial community dynamics, and plant health. These exudates comprise primary metabolites, such as sugars, amino acids, and organic acids, as well as secondary metabolites, including flavonoids, phenolics, and alkaloids, along with various enzymes and signaling molecules. Their secretion is tightly regulated by hormones, which orchestrate root development, exudate composition, and adaptive responses to environmental cues. Understanding hormones' role in the root exudation process for plant development and interaction is important; therefore, we aimed to summarize and synthesize recent findings to highlight the roles of major hormones in regulating root exudation, including auxins, cytokinins (CK), gibberellins (GA), abscisic acid (ABA), ethylene, jasmonates (JA), salicylic acid (SA), brassinosteroids (BRs), and strigolactones (SLs). The current understanding summarizes how hormone signaling pathways, crosstalk, and developmental stage transitions modulate exudate profiles, thereby shaping rhizosphere interactions. Particular attention is given to defense-related exudation under biotic and abiotic stress, nutrient mobilization, and the promotion of beneficial microbial associations. The implications of hormone-regulated exudations for sustainable agriculture are discussed, with an emphasis on strategies to enhance nutrient uptake, improve stress resilience, and reduce chemical inputs. Finally, key knowledge gaps are identified, particularly the limited integration of controlled studies with field-based complexity, and the potential for integrating emerging tools, such as hormone-responsive biosensors and metabolomics, to advance agricultural settings is discussed.

Plants rely on sophisticated intercellular communication to coordinate systemic responses to environmental challenges. Electrical signals contribute for rapid, long-distance integration of plant parts. This study investigated how distinct stressors-localized injury (cutting and fire to a leaflet) and systemic salt stress (applied to the roots)-triggered electrical synchronization across different modules (stem and leaves) in soybean (Glycine max) plants. We continuously recorded variations of electrical potential from four plant modules before and after stress application. Time-series analyses, including Detrended Fluctuation Analysis (DFA), Approximate Entropy (ApEn), Fast Fourier Transform (FFT), and Power Spectral Density (PSD), were employed to characterize signal features. Inter-modular synchronization was then assessed by Pearson correlation of these derived features between the modules. The results indicate that different stressors modulate electrical synchronization between plant modules in distinct ways: while cutting and fire stress induce a more immediate and integrated response, showed as higher correlation between modules, salt stress promotes more gradual changes in signal dynamics. These findings reinforce the hypothesis that electrical signalling plays an important role in the functional integration of stress responses, and may indicate a possible attentional state in plants.

The use of biological control agents offers a sustainable alternative to chemical pesticides for managing soil-borne plant diseases. This study investigates the biocontrol potential of a newly isolated yeast strain, Meyerozyma guilliermondii INAT-MT731365, as a biotic elicitor to enhance growth and Fusarium crown and root rot (FCRR) resistance in hydroponically grown tomato plants. Tomato plants were treated with M. guilliermondii or left untreated as controls, then divided into two groups, one infected with Fusarium oxysporum f. sp. radicis-lycopersici (FORL) and one not infected. Physiological, biochemical, and molecular responses were monitored after treatment and inoculation. In the absence of the pathogen, M. guilliermondii treatment significantly enhanced plant growth and chlorophyll content. Concurrently, the yeast elicited a priming effect, characterized by low-level upregulation of PR1, β-1,3-glucanase and chitinase genes, downregulation of the P69G gene, and activation of defense enzymes such as peroxidase, chitinase, and β-1,3-glucanase, along with increased phenolic content and hydrogen peroxide accumulation, indicative of both SA- and JA/ET-mediated signalling induced systemic resistance (ISR). In control plants, FORL impaired plant defense with an early downregulation of β-1,3-glucanase and chitinase genes and stability in PR1 gene expression, followed by transient activation of peroxidase and chitinase and low activation of catalase, β-1,3-glucanase, and accumulation of phenolics. Upon FORL infection, treated plants exhibited strong upregulation of PR1, chitinase and β-1,3-glucanase genes mirrored by sustained increases in H₂O₂ and phenolic content and peroxidase, catalase, chitinase and β-1,3-glucanase activity. The simultaneous activation of both SA- and JA/ET-mediated signalling ISR resulted in a 61.8% reduction in FCRR severity and improved growth and photosynthetic traits. These findings highlight M. guilliermondii as a promising biocontrol agent that primes tomato plants for faster, stronger responses to soilborne pathogens while promoting growth under both healthy and stress conditions.

The conservation of rare and endangered plant species has progressed with the advent of nanotechnology, enabling their large-scale production with desirable traits. The present study was focused on the synthesis of zinc oxide nanoparticles (ZnO-NPs) using the aqueous extract of Convolvulus arvensis and their characterization using various techniques (UV spectra, FTIR, transmission electron microscopy (TEM), and zeta potential), and further, their impact was assessed on callus and in vitro raised shoots of Reseda lutea. Low concentrations of ZnO-NPs (15 and 30 mg/L) increased the fresh weight of shoots by 35.38% and 17.43%, respectively. In contrast, a high concentration of ZnO-NPs (60 mg/L) in MS medium resulted in a 29% decrease in shoot biomass. The different concentrations of ZnO-NPs (15, 30, and 60 mg/L) increased the callus biomass by 70.7%, 62.6%, and 24.8%, respectively, compared to the control. The total phenolic content (TPC) and flavonoid content (TFC) in both regenerated stages were varied, and they were increased in callus by 15.5% with 60 mg/L of ZnO-NPs, whereas TPC and TFC were reduced in shoot, and a greater reduction was observed in TFC with the same concentration of ZnO-NP treatment than the control. The biochemical analysis performed on callus and shoot revealed a dose-dependent accumulation of proline and TBARS content. The accumulation of total soluble protein improved in both regeneration stages, and its content varied with different treatment doses of ZnO-NPs. A close relationship was observed in protein accumulation by 26.24%, and chlorophyll contents by 36.4% in shoots with 15 mg/L ZnO-NPs than the control, while both parameters decreased with 60 mg/L ZnO-NPs. The activities of antioxidant enzymes, including GR, SOD, and APX, varied under different treatment doses of ZnO-NPs. The flow cytometry (FCM) results of callus and shoot with ZnO-NPs treatment confirmed the genetic stability by genome size (2C DNA content). The results of this study show that biogenic ZnO-NPs positively influence various attributes of the callus and shoot stages and may support the mass production of R. lutea with abiotic stress tolerance.

The genus Fusarium includes some of the most detrimental pathogenic fungi to crops, significantly impacting cereal growth and food production. It causes devastating diseases such as banana wilt caused by Fusarium oxysporum and Fusarium head blight caused by Fusarium graminearum. Beyond causing substantial yield losses, Fusarium species produce various mycotoxins that pose serious risks to crop safety and human health. Recent advances in genome sequencing have uncovered numerous genes involved in secondary metabolism, hyphal development, reproduction, and virulence mechanisms in Fusarium. This review summarizes current knowledge on the growth, development, and pathogenesis of the Fusarium, with a focus on F. oxysporum and F. graminearum. Elucidating these mechanisms is crucial for developing targeted fungicides and innovative management strategies to control Fusarium diseases, thereby reducing their agricultural and health impacts.

The genus Azospirillum celebrates 100 y since its discovery in 1925 by Martinus Willem Beijerinck, who worked with Spirillum lipoferum as a starting species. Decades of work involving laboratory and field research endorse their various beneficial properties, such as plant rooting, mineral nutrition, hormonal strengthening, and the activation of cellular and molecular responses, which lead to better growth, development, and productivity. Some hormones, such as auxins and cytokinins, potentiate root branching through their effects on mitosis, and via signal transduction mediated by the Target Of Rapamycin (TOR) kinase. Although initial efforts were aimed at clarifying the importance of biological nitrogen fixation in plant growth in the face of root colonization with Azospirillum, recent advances show that these bacteria also activate the mechanisms of acquisition of phosphorus and iron, two essential nutrients for fulfilling the plant's life cycle. In recent years, Azospirillum structural elements such as flagellin and lipopolysaccharides emerged as elicitors, influencing the development and defense of the host. Goals have also been achieved in formulating biotechnological products, whose application has increased in countries such as Argentina and Brazil, showing relevant and promising results toward saving fertilizer, optimizing management, and ultimately, making agriculture more sustainable.

In both animal and plant cells extracellular nucleotides act as hormone-like signals regulating many important physiological and developmental responses. In plants, many of these responses have been studied in roots. Here we used an enzyme-based microsensor to measure the concentrations of extracellular ATP (eATP) within 2 µm of epidermal cell surfaces in growth zones of primary roots of wild-type and transgenic Arabidopsis seedlings. The concentration of eATP outside of growing wild-type roots was in the nanomolar range and was highest in in the elongation zone. The concentrations of eATP in wild-type roots were altered in two kinds of mutants, those that were overexpressing AtAPY1 or AtAPY2, which encode apyrases (NTPDases) that regulate root and root hair growth, and those that were suppressed in the expression of these two transcripts. Our results indicate that the [eATP] measured varies inversely with the level of expression of these apyrases. Structural modeling of these two apyrases predicts active site configurations capable of binding ATP. Taken together these results favor the hypothesis that AtAPY1 and AtAPY2 regulate eATP levels in primary roots.

Accurate selection of reference genes is crucial for reliable gene expression analysis in plants. Traditional reference genes, such as GAPDH and ACT, are widely used but often show variable stability under different conditions, stresses, tissue types, and developmental stages. Recent advances in multi-omics technologies, including transcriptomics, offer new approaches for improving reference gene selection. These methods allow for the integration of diverse datasets to identify genes with stable expression across various environmental stresses and developmental stages, providing more robust and context-specific normalization controls. High-throughput sequencing technologies, such as RNA-seq, have enabled the large-scale identification of stable reference genes, and further enhanced this process by correlating gene expression at the transcript level. Additionally, the application of computational tools helps researchers optimize reference gene selection, making the process more efficient and standardized. Personalized and condition-specific reference gene databases are emerging as valuable resources for selecting the most appropriate genes based on experimental conditions. This paper explores the current trends and challenges in reference to reference gene selection and the potential of a transcriptomics approach to address these challenges. The use of these advanced methods will increase the accuracy and reliability of plant gene expression studies, accelerate discoveries in crop improvement and stress resilience in plant biology and agricultural sciences.

Mechanical damage to plants triggers both localized and systemic responses that activate plant defense mechanisms. Early signaling events include calcium (Ca²⁺) flux, reactive oxygen species (ROS), and electrical alterations. These signals coordinate downstream defense pathways, enabling plant acclimation to biotic stress. Electrical signaling following wounding/herbivory has been extensively studied in Arabidopsis; however, its dynamics in crop plants such as chickpea (Cicer arietinum) are not well understood. The pattern of the SWP in chickpea was similar to that in Arabidopsis but with a longer repolarization phase and was detectable only within the leaflets. The signals generated by damaging the leaflet were more pronounced, propagated bidirectionally and varied between herbivore-susceptible and tolerant chickpea varieties. The SWP duration is correlated with increased expression of AOS and OPR3 transcripts, which are markers of the stress hormone JA. Additionally, ROS production in wounded chickpea leaflets is associated with increased expression of ROS-generating genes. The use of DPI, an inhibitor of NADPH oxidase, which is responsible for ROS production, inhibited SWP, suggesting the crucial role of ROS in wound-induced SWP. This study provides insight into the interplay between wound-induced electrical signaling and ROS production in chickpea and proposes the measurement of electrical signals as a rapid, noninvasive approach for screening crop cultivars for pest susceptibility and tolerance.