Physiologia plantarum最新文献

Valsa canker, a disease caused by necrotrophic fungi belonging to the genus Valsa, ranks among the most destructive pathogens jeopardizing the sustainable development of the pear and apple industries. The identification of resistance-related genes is therefore of great significance for advancing resistance breeding efforts and formulating effective disease control strategies. Receptor-like proteins (RLPs) are crucial membrane-localized sensors that play significant roles in diverse plant immunological processes. Still, the regulatory roles of RLPs in the Valsa canker resistance remain elusive. In this study, we found that a leucine-rich repeat receptor-like protein (LRR-RLP) gene, PbeRLP3, was highly induced by Valsa pyri in 'Duli-G03' (Pyrus betulifolia, a rootstock of pear) suspension cells. Overexpression of PbeRLP3 in 'Huangguan' pear (P. bretschneideri), 'Fuji' apple (Malus domestica) fruits, and 'Duli-G03' suspension cells significantly improved resistance to Valsa canker. However, the resistance contributed by PbeRLP3 was largely compromised by removing its Transmembrane (TM) region. RNA-seq and qRT-PCR analyses demonstrated that the expression of multiple genes associated with salicylic acid (SA), pattern-triggered immunity (PTI), and abscisic acid (ABA) pathways were induced in PbeRLP3-OE cells. Furthermore, Weighted Gene Co-Expression Network Analysis (WGCNA) displays that PbeRLP3 is co-expressed with 3 RLP genes and 17 Receptor-like kinase genes (RLKs). The results presented herein provide fresh insights into the effective screening of RLP genes related to resistance using specific molecular approaches, along with their application in follow-up molecular breeding strategies for boosting plant resistance.

SnRK1 protein kinases play a pivotal role in regulating plant development, growth signaling, and stress responses by managing cellular responses to energy fluctuations. SnRK1 activation was thought to depend mainly on the phosphorylation of threonine at position 175 (Thr175) within the activation loop. However, recent phosphoproteomic studies have identified additional phosphorylation sites. We explored the functional significance of these modifications, focusing on serine at position 176 (Ser176), adjacent to Thr175 in SnRK1α1. Our results reveal that dual phosphorylation of Ser176 and Thr175 is vital for optimal SnRK1 activity. Structural modeling and thermodynamic analyses highlight the critical role of these modifications in optimising substrate positioning and enzymatic efficiency. Furthermore, only the wild-type SnRK1α1, which can be phosphorylated at both sites, retains full functionality in in vivo experiments with yeast and Arabidopsis. Interestingly, pSer176 exhibits greater stability than pThr175 at various times throughout the day. Mutant proteins with substitutions at these sites (T175A/S176A mutants) accumulate in cytoplasmic aggregates after heat shock, suggesting a strong link between phosphorylation status, protein stability, and SnRK1 degradation pathways.

Atractylodes macrocephala Koidz., a perennial medicinal herb of the Asteraceae family, holds significant therapeutic value in traditional medicine. It is primarily recognized for its ability to strengthen spleen and stomach functions and modulate gastrointestinal activity. In this study, the molecular mechanisms governing sesquiterpenoid biosynthesis in A. macrocephala were investigated through an integrated sequencing strategy combining next-generation sequencing (NGS) and single-molecule real-time (SMRT) sequencing. Transcriptomic analysis identified 17,846 differentially expressed genes (DEGs) in rhizomes from three geographical origins, including 5196 upregulated and 12,650 downregulated genes. Nine full-length terpene synthase (TPS) genes were successfully retrieved. Comprehensive functional characterization of these AmTPS genes was performed using amino acid sequence analysis, multiple sequence alignment, phylogenetic reconstruction, quantitative real-time PCR (qRT-PCR), and heterologous expression assays. AmTPS8 and AmTPS9 were assigned to the TPS-a subfamily. Notably, AmTPS8 displayed the highest transcript abundance in samples from the Yuexi region, whereas AmTPS9 was most highly expressed in rhizomes from the Bozhou region. Enzymatic assays demonstrated that AmTPS8 catalyzes the formation of bulnesol, while AmTPS9 exhibits juniper camphor synthase activity. Overall, this study provides important insights into terpenoid biosynthesis in A. macrocephala and establishes a molecular basis for future research aimed at enhancing sesquiterpenoid production and elucidating regulatory mechanisms within this medicinally important species.

In legumes, flowering time is regulated by genes responsive to temperature and photoperiod, presenting challenges for high-latitude lentil producers who must adapt cultivars to short growing seasons and extended daylight hours. Therefore, prolonged vegetative periods are favored in those areas. To address this, we studied a recombinant inbred line (RIL) population, derived from a cross between the adapted cultivar CDC-Milestone and the non-adapted line ILL8006, to investigate phenology-related traits under long-day conditions in western Canada. Significant variation in days to emergence (DTE), days to flowering (DTF), and days to pod maturity (DTM) enabled analysis of the vegetative (VegP) and reproductive (RepP) periods within the population. We constructed a high-density genetic linkage map using molecular markers linked to genes in the Lcu.2RBY reference genome, identifying quantitative trait loci (QTLs) for those traits across four site-years in Saskatchewan. Differential expression analysis of known flowering time genes enhanced interpretation of the QTL results for flowering time. Three major DTE QTLs (qDTE2/3.II, qDTE2/3.III, and qDTE2/3.IV) on chromosome 2 explained 16%-28% phenotypic variability, depending on the environment, with in silico analysis identifying six curated genes as putative candidates within that region. A key DTF QTL (qDTF6.I) on chromosome 6 accounted for 23%-56% of phenotypic variability, harboring a homolog of the FLOWERING LOCUS T gene, whose role was explored alongside other candidate genes. Dissecting the vegetative period into DTE and DTF revealed distinct genetic controls for each trait, enabling breeders to combine early or late emergence and flowering to optimize adaptation and yield in diverse agroclimatic conditions.

Drought and salinity are significant challenges to tomato production under climate change. A 2-year experiment (2023-2024) with Solanum lycopersicum cv. Resi evaluated the effects of drought (25%, 12.5%, and 6.25% of soil weight) and salinity (0.5% and 1.0% NaCl), applied individually and in combination, on yield, mineral uptake, and secondary metabolism. Drought reduced yield by 28%, salinity by 17%, and their combination by 27%. Moderate drought and salinity increased potassium (K⁺) uptake, whereas severe stress reduced calcium (Ca²⁺) concentration and disrupted overall ionic homeostasis. Lycopene and β-carotene decreased under combined stress, whereas chlorogenic acid and naringenin chalcone increased, indicating enhanced antioxidant metabolism. Antioxidant activities (TEAC, DPPH, and TPC) rose under moderate stress, particularly in the warmer 2024 season. Correlation analysis showed that magnesium (Mg²⁺) accumulation was positively associated with antioxidants and carotenoids, supporting redox balance under stress conditions. Overall, these findings indicate that tomato adaptation to drought and salinity relies on coordinated ionic regulation and antioxidant adjustments, both influenced by environmental conditions.

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.

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.

Leaves maintain a pool of non-structural carbohydrates (NSC) whose size can vary over hourly and longer timescales. We tested two long-standing hypotheses regarding potential physiological roles of changes in foliar NSC levels. The first is that soluble NSC plays a critical role in osmotic adjustment, with their increase enabling stomatal opening despite daily and seasonal reductions in leaf water potential (Ψ_leaf). The second is that increases in NSC are a sign of excess assimilation relative to sink demand and serve as a signal to downregulate gas exchange. To explore these questions, we monitored the diurnal and seasonal dynamics of gas exchange, Ψ_leaf, osmotic potential, and NSC of irrigated and dehydrated grapevines (Vitis vinifera) through two consecutive growing seasons. We found that the daily accumulation of soluble sugars constitutes approximately 50% of the daily osmotic adjustment (0.2 MPa), enabling the vines to maintain turgor under low Ψ_leaf. At the same time, the importance of NSC as osmolytes decreased as the season progressed, and they did not contribute to osmotic adjustments when water was withheld. Additionally, there was no negative correlation between NSC and gas exchange, implying that bulk NSC concentration is not the signal for photosynthetic feedback inhibition.