Physiologia plantarum最新文献

As the human population is growing and the environment is degrading, breeding resilient and high-yield crop cultivars is a practical strategy for food security. Genetic modifications including transgenic techniques require identification and functional characterization of resource genes for higher yield and resilience. Histone acetylation is associated with gene activation and plays important roles in both plant development and stress responses in plants. Maize is a typical C4 crop with a high capacity for resilience and assimilation, but few of its histone acetyltransferase genes (HAT) have been identified and functionally characterized. In this study, we identified 14 HAT genes in maize and analyzed their expression patterns. Zm00001eb109790 (ZmATF2) encodes a putative histone acetyltransferase located in the nucleus. The overexpression of ZmATF2 enhanced salt tolerance and increased the total yield per plant through boosting the tillering of transgenic rice, which was accompanied by heightened histone acetylation and altered expression patterns of a plethora of development-related genes and stress-responsive genes. Treatment with a chemical inhibitor of histone acetyltransferases dampened the salt tolerance conferred by ZmATF2, further supporting the role of ZmATF2 as a histone acetyltransferase in transgenic rice. This study systematically analyzed the ZmHAT family and revealed the role of ZmATF2 in salt stress response and plant development using rice as a model plant. Our results provide a genetic modification-based strategy for simultaneously improving stress tolerance and yield in rice plants.

Abscisic acid (ABA) plays a crucial role in plants' adaptation to drought and salinity. This study used Y2H (Yeast two-hybrid system), GST pull-down, and LCI (Firefly luciferase complementation imaging assay) approaches to reveal the role of the interaction between OsAE7 (asymmetric leaves1/2 enhancer 7) and ZFP36 (zinc finger protein 36) in rice. Subcellular localization analysis revealed that OsAE7 is localized in the nucleus. After treatment with ABA, H₂O₂, osmotic stress (polyethylene glycol, PEG), and NaCl, the expression level of OsAE7 genes in leaves has increased. Experiments with H₂O₂ scavenger (DMTU) and NADPH oxidase inhibitor (DPI) indicated that ABA induces the up-regulation of OsAE7 expression through increased ROS production. The OsAE7 gene knockout mutant osae7-KO was constructed using the CRISPR/Cas9 system and Agrobacterium-mediated method, and T₁ generation homozygous lines osae7-1 and osae7-2 were obtained. Under simulated stress with PEG and NaCl, the antioxidant defense enzyme activity, relative water content, and proline content of the osae7-KO mutant were significantly lower than those of the wild type, while the malondialdehyde content and relative plasma membrane permeability were significantly higher, indicating that the osae7-KO mutant has lower stress resistance. osae7-KO plants were also much less sensitive to ABA than the wild type. qRT-PCR analysis showed that the interaction with ZFP36 affects the induction of OsAE7 by ABA. In conclusion, OsAE7 is involved in the ABA signaling pathway and plays a role in the plant's response to drought and salt stresses.

Drought limits forage productivity and causes physiological dysfunction in plants. Melatonin (MT) can enhance stress tolerance, but the optimal dose and the mechanisms by which it mitigates drought-induced physiological and metabolic disturbances in Leymus chinensis remain unclear. A pot experiment under controlled soil moisture was conducted to screen the optimal MT dose for alleviating drought stress in L. chinensis seedlings and to elucidate the key physiological and metabolic mechanisms involved. Adding 100 μM MT significantly improved growth and photosynthetic performance under drought (p < 0.05). Specifically, DM100 increased plant height, root length, stem diameter, aboveground fresh weight (FW), aboveground dry weight (DW), and leaf relative water content (RWC) by 51.91%, 20.95%, 38.40%, 192.57%, 192.41% and 12.52%, respectively. Gas-exchange parameters were likewise enhanced (Gs: 183.38%, Tr: 270.37%, Pn: 114.24%), whereas intercellular CO₂ concentration (Ci) decreased by 113.34% (p < 0.05). Under drought, activities of antioxidant enzymes-superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT)-were significantly elevated, and DM100 further increased these activities; conversely, drought-induced proline (Pro) accumulation was reduced by MT treatment. Untargeted metabolomics showed that drought markedly upregulated biosynthetic pathways for tryptophan, phenylalanine, phenylpropanoids and flavonoids. DM100 selectively attenuated excessive activation of tryptophan and phenylalanine metabolism, modulated phenylpropanoid/flavonoid responses, and coordinately regulated antioxidant and osmotic-adjustment metabolism. In summary, foliar MT at 100 μmol·L^-1 appears to rebalance drought-induced metabolic perturbations by selectively modulating stress-responsive pathways rather than broadly activating metabolism, thereby improving photosynthetic performance, antioxidant capacity and growth in L. chinensis.

Anthocyanins are specialized plant metabolites with significant dietary value due to their anti-inflammatory properties. Research indicates that dietary intake of these phenolic compounds contributes to preventing various chronic diseases. As the most consumed vegetable worldwide, tomato (Solanum lycopersicum) is an excellent candidate for anthocyanin-enrichment strategies. In tomato, the activation of anthocyanin biosynthesis is light-dependent, but this mechanism has yet to be entirely characterized. We investigated the role of light in anthocyanin biosynthesis in purple tomato fruits generated by combining the Anthocyanin fruit (Aft), atroviolacea (atv), and high-pigment 2 (hp2) mutations into cv. Micro-Tom (MT). MT-Aft/atv/hp2 starts accumulating anthocyanins early during fruit development, but this accumulation is restricted to the peel (exocarp and epicarp). By manipulating light incidence in different fruit tissues, we determined that the absence of anthocyanin accumulation in the flesh results from the sun-blocking effect of the cyanic epicarp on the flesh (mesocarp), thus preventing light from penetrating deeper into the fruits. Comparative transcriptional analyses of the fruit peel and flesh indicated that the bHLH transcription factor SlAN1 (Solyc09g065100) may be the limiting factor for light-dependent anthocyanin accumulation in both tissues. This research enhances our comprehension of the genetic and environmental regulation of anthocyanin accumulation in fruit tissues, offering valuable insights into plant breeding for human nutrition.

Soybean growth and yield are susceptible to abiotic stresses such as phosphate (P) deficiency and drought. Symbiotic association of plant roots with arbuscular mycorrhizal fungi (AMF) can improve water uptake, thereby increasing stress resilience. This study evaluates the interactive effects of P availability, drought, and AMF symbiosis on physiology, reflectance traits, roots, and metabolite responses in two soybean genotypes during the early reproductive stages. Under P deficiency (P-), AMF colonization significantly (p < 0.05) increased, enhancing root hair development and maintaining ~30% lower leaf water potential (Ψ) under drought stress. Drought significantly (p < 0.05) negatively impacted photosynthesis as well as triggered shifts in metabolite accumulation and reflectance-based vegetation indices in both P treatments. P- sufficient (P+) plants developed significantly higher biomass. Chlorophyll-related vegetation indices were more responsive to P during drought, showing 45%-60% reductions in P- plants compared with only 25%-35% in P+ plants. The ratio of red-to-far-red chlorophyll fluorescence also significantly decreased (10%) under drought, indicating altered canopy spectral balance and stress-induced pigment changes. Carbohydrates, jasmonic acid, and amino acids exhibited significant variations (p < 0.05) among genotypes and P treatment under drought. Interestingly, a metabolite involved in phylloquinone biosynthesis (C₁₁H₁₂O₆) was strongly upregulated under drought in P- plants with a strong correlation (r = 0.72) to Ψ. These findings highlight the critical role of P in AMF symbiosis for drought resistance. The integration of remote sensing and mass spectrometry-based metabolite profiling provides a comprehensive multiscale approach to link physiological and molecular responses, facilitating rapid and informed breeding decisions under diverse environmental stresses.

In plants, BIN2 is a well-known member of GSK3, a major negative regulator of brassinosteroid (BR) signaling. GSK3s play a vital role in the abiotic stress response in plants, regulating salinity stress responses and influencing heat and drought resistance. To evaluate the impact of cold stress on tomato, SlBIN2.1-overexpressing and SlBIN2-knockout lines were exposed to cold stress alongside WT. The expression of genes encoding enzymes involved in enzymatic activity, including Cu/Zn SOD, POD1, and CAT1, was increased in the knockout lines, thereby improving the activity of these enzymes. On the other hand, the expression of these genes was comparatively lower in the SlBIN2.1-OE lines and, hence, reduced enzymatic activity. MDA and H₂O₂ were highly accumulated in overexpressed lines, while proline content was increased in the knockout lines compared to other plants. Expression of cold-related genes, including CBF1, CBF2, CBF3, NCED1, and NCED2, was upregulated in the knockout lines compared to both overexpressed and WT plants. Transcriptomic data show that core pathways related to cold response were negatively regulated in SlBIN2.1-OE and, hence, decreased cold stress tolerance in tomato. Overall, SlBIN2 knockout improves cold stress response in tomato by regulating enzymatic activity and expression of cold-related genes.

Plant growth-promoting rhizobacteria (PGPR) establish beneficial associations with plants, enhancing nutrient uptake, growth, and stress tolerance. Cannabis sativa L., a medicinal plant producing over 300 specialized metabolites with relevant medicinal properties, remains underexplored for PGPR influence on its metabolism. This study assessed the ability of four PGPR taxa: Bacillus, Pseudomonas, Flavobacterium, and Burkholderia to colonize roots and modulate cannabinoid metabolism. Two Δ⁹-tetrahydrocannabinolic acid (THCA) drug-type C. sativa cultivars, Amnesia Haze and Gorilla Glue, were tested. Plants grown hydroponically were inoculated under controlled conditions. Root colonization was confirmed via endophyte-specific assays. Phenotypic analyses revealed no effects on plant phenotype, while chemical analyses revealed a response shared across taxa and cultivars. Bacterial inoculation increased the precursor cannabinoid Cannabigerolic acid (CBGA) concentration significantly by +27.37% while reducing Δ⁹-tetrahydrocannabinol (Δ⁹-THC) by -15.76%. The CBGA/THCA and THCA/CBDA ratios shifted significantly, indicating a favored CBGA accumulation and CBDA production, respectively. PGPR treatments reduced in vivo and post-harvest decarboxylation of THCA into Δ⁹-THC, preserving the acidic cannabinoid profile. Under a standardized, soilless hydroponic regimen with a single shared reservoir and identical fertigation across groups, PGPR colonization was associated with shifts in cannabinoid metabolism and reduced decarboxylation. This study demonstrates that PGPR can influence the specialized metabolism of high-THCA C. sativa, offering insights into sustainable cultivation and pharmaceutical exploitation of this relevant medicinal plant species.

Autotoxicity, primarily mediated by cinnamic acid (CA), is a major contributor to continuous cropping obstacles in melon (Cucumis melo L. cv. Xin Yinhui), severely inhibiting plant growth. Melatonin (MT), a pleiotropic signaling molecule, enhances plant stress tolerance. This study investigated the protective role of exogenous MT against CA-induced autotoxicity in melon seedlings by comprehensively assessing growth, photosynthesis, reactive oxygen species (ROS) accumulation, and antioxidant enzyme activities. Exposure to 0.4 mM CA severely inhibited seedling growth, reducing the relative growth rate of plant height, leaf area, and fresh weight by up to 67.71%, 59.60%, and 74.47%, respectively, and causing significant root damage. CA severely impaired photosynthesis, depressing the net photosynthetic rate (Pn) and the maximum photochemical efficiency of PSII by 69.52% and 5.27%, respectively. CA also induced severe oxidative stress, as evidenced by substantial ROS accumulation and marked decreases (21.78%, 40.45%, and 47.41%, respectively) in the activities of key antioxidant enzymes: superoxide dismutase, catalase, and ascorbate peroxidase. Exogenous application of 4 μM MT effectively mitigated these stresses. MT treatment promoted root recovery, increased leaf area and fresh weight by 40.24% and 88.25% compared to the CA-stressed group, and alleviated oxidative damage by directly scavenging ROS and restoring root antioxidant enzyme activities to near-control levels. Furthermore, MT enhanced the quantum efficiency of PSII reaction centers and electron transport, culminating in a substantial recovery of Pn. Collectively, our findings demonstrate that exogenous MT comprehensively alleviates CA-induced autotoxicity in melon seedlings through coordinately improving growth, antioxidant capacity, and photosynthetic function.

Accurate detection of tomato ripeness and size is critical for robotic thinning and harvesting but remains challenged by performance degradation in adverse weather, imprecise size estimation, and computational constraints on edge devices. To bridge this gap, we introduced (1) the TIDAW dataset (Tomato Images in Diverse Adverse Weather), synthetically generated via a physically-grounded atmospheric scattering model to simulate realistic rain and fog; and (2) Edge-YOLO-Tomato, a novel YOLOv8-based architecture, featuring four key innovations: a physics-aware scattering module that unifies multi-particle light transport theory with dual-attention mechanisms to explicitly model wavelength-dependent scattering for robust feature disentanglement; dilated convolutions enhancing receptive fields; a prior-embedded Wise-IoU loss incorporating botanical size distribution priors to rectify bounding box bias; and a compression framework that combines magnitude pruning and layer-wise pruning using neural architecture search. Extensive evaluations demonstrate leading performance: Edge-YOLO-Tomato achieves 93.3% mAP₅₀ and 74.3% mAP_50:95 on TIDAW, surpassing YOLOv8, YOLOv11, Faster R-CNN, and RT-DETR etc. by 1.1%-26.3% and 0.2%-2.2%, respectively. The compressed model attains a 4.7373 MB footprint (20.58% size reduction) with ≦ 0.5% accuracy loss and delivers 50% latency reduction on CPU. This work establishes a new paradigm for vision-based precision agriculture by unifying physical data synthesis, physics-aware modeling, and compression framework, enabling real-time robust fruit detection in uncontrolled environments. The codes are available at https://github.com/YLu567/Edge-YOLO-Tomato.