Physiologia plantarum最新文献

To explore how plant growth-promoting rhizobacteria (PGPR) regulate stress-tolerant plant growth and enhance heavy metal remediation under combined cadmium (Cd) and salt stress, we conducted hydroponic experiments using Suaeda salsa inoculated with Escherichia coli-10,527. We investigated the changes in plant growth and stress tolerance, Cd translocation, cell ultrastructure, Cd subcellular distribution, and gene expression under hydroponic conditions. The results showed that inoculation improved plant biomass, stress tolerance, and Cd uptake, particularly under low Cd/salt concentrations. E. coli-10,527 colonized lateral root zones and secreted extracellular polymeric substances (EPS), which promoted flavonoid accumulation (by 12.68%-36.76%), thereby enhancing root growth and Cd accumulation. Compared with the uninoculated control, E. coli-10,527 inoculation altered the subcellular distribution of Cd in S. salsa; the proportion of Cd in the cytoplasm increased from 16.29% (29.06%) to 24.28% (45.57%) in roots (shoots). Transcriptomic analysis revealed the upregulation of genes (ZIPA, NRAMP3, and HMA4) potentially involved in enhanced Cd transport and vacuolar sequestration. Overall, inoculation with E. coli-10,527 can promote root development in S. salsa under Cd and salt stress, while facilitating simultaneous phytoremediation of Cd and salt. This study provides an effective microbial inoculation strategy for Cd remediation in saline soils affected by combined stresses.

Proteomics is defined as the identification, quantification, and characterization of the complete set of proteins expressed in a cell or tissue under specific conditions. The last two decades have witnessed rapid advancements in proteomics technologies, including the development of the Data-Independent Acquisition (DIA) mode, which has significantly improved the sensitivity, reproducibility, and depth of proteome coverage. These advancements, together with the development of cutting-edge data analysis tools, have undoubtedly facilitated the identification of stress-responsive proteins and potential biomarkers in different organisms. However, the identification of such stress-responsive proteins, particularly in plants, remains relatively challenging because of the presence of various high-abundance proteins such as RuBisCO, which hinders the identification and subsequent characterization of these stress-responsive proteins due to their low abundance. More recently, a four-dimensional (4D) proteomics approach has been introduced, which includes "ion mobility" as the fourth dimension to classical quantitative proteomics. This 4D-proteomics method utilizes trapped ion mobility spectrometry (TIMS) combined with parallel accumulation-serial fragmentation (PASEF), which significantly enhances the sensitivity and coverage of proteomics experiments, thus allowing the detection of low-abundance proteins. This review highlights the evolution of proteomic technologies, the development of the 4D proteomics workflow, and their potential application in unraveling the molecular mechanisms underlying plant responses to environmental stress conditions. In essence, this review article provides a comprehensive overview of the state-of-the-art in proteomics, emphasizing its transformative impact on plant science research and its potential to understand crop stress resilience.

The accumulation of excess manganese (Mn) is toxic to plants and limits agricultural productivity. Although selenium (Se) is known to be a beneficial element that can alleviate heavy metal stress, its role in mitigating Mn-related stress remains insufficiently explored. This research explores the effects of Se (applied as sodium selenite at 0.5 μM) on 0.5 mM Mn toxicity in Malus robusta seedlings, focusing on Mn accumulation, physiological performance, polyamine metabolism, proline biosynthesis, and the enzymatic activity and expression levels of critical genes. Exogenous Se significantly reduced Mn accumulation and alleviated Mn toxicity, as evidenced by enhanced root growth, increased photosynthetic pigments, improved fluorescence parameters (Fv/fm and ΦPSII), and maintained antioxidant balance via a reduced production of reactive oxygen species (ROS) and an activation of the antioxidant system. Moreover, total putrescine (Put) and spermine (Spm) contents declined after Se application, whereas spermidine (Spd) levels showed no noticeable change. This led to an increased (Spd + Spm)/Put ratio, highlighting the pivotal role of Put reduction in Mn stress response. A decrease in Put corresponded with significant downregulation of ornithine decarboxylase (ODC; EC 4.1.1.17) and arginine decarboxylase (ADC; EC 4.1.1.19) activities and gene expressions. Furthermore, soluble conjugated and insoluble bound polyamines followed a similar trend, except for a notable increase in bound Spd. In addition, Se treatment decreased proline (Pro) content mainly through the suppression of ornithine aminotransferase (OAT; EC 2.6.1.13). It is observed that Se enhances the ability of M. robusta to withstand Mn stress by regulating polyamine and proline metabolism, thereby highlighting a possible mechanism for reducing Mn toxicity in plants.

Abiotic stress, particularly heat and drought, significantly impacts plant reproductive development, threatening crop productivity and food security. Understanding stress tolerance mechanisms requires a multi-level approach that integrates physiological, biochemical, and molecular traits in different experimental settings. This review explores key methodologies for assessing resilience to single and combined abiotic stress in reproductive tissues, from growth chamber experiments to greenhouse and field trials. Essential physiological and biochemical traits indicative of stress responses are highlighted alongside molecular pathways that provide deeper insights into adaptation to drought and heat stress. The use of multi-omics techniques, including transcriptomics, proteomics, and metabolomics, as powerful tools for identifying novel stress-associated traits is discussed, with an emphasis on the integration of these techniques into a holistic framework, which also incorporates single-cell approaches. Finally, we address the limitations of the current methodologies and propose future research directions to improve stress resilience assessment in plant reproductive development.

Increasing soil salinization poses a severe threat to global agricultural production. Quercetin, a natural compound known to effectively alleviate abiotic stress, has an unclear molecular regulatory mechanism in enhancing soybean salt tolerance. To investigate its mechanism of action, this study established control, quercetin treatment, salt stress, and quercetin plus salt stress groups. By integrating physiological indices with transcriptomic and metabolomic analyses, we systematically elucidated the molecular mechanisms by which exogenous quercetin enhances salt tolerance in soybeans. The results demonstrated that quercetin treatment not only significantly improved root growth and ionic homeostasis (increased K⁺/Na⁺ ratio) under salt stress but also enhanced energy supply by reinforcing sucrose metabolism and the tricarboxylic acid cycle. Furthermore, it coordinately regulated key genes in the abscisic acid and jasmonic acid signaling pathways to bolster stress responses, while simultaneously promoting proline accumulation and reprogramming the flavonoid metabolic pathway. Thereby, a multifaceted regulatory network for salt tolerance was constructed. This study provides new insights into the role of quercetin in plant stress resistance and offers a theoretical basis for crop breeding for improved stress tolerance.

Rosa roxburghii fruits are highly favored by Chinese consumers due to their substantial nutritional value, particularly the richness in vitamin C and flavonoids, contributing to the fruits' high economic significance. However, the specific composition and biosynthetic mechanisms of key pigments, including flavonoids, phenylpropanoids, and anthocyanins during the fruit's color development, remain unclear. In this study, we conducted an integrated phenotypic, metabolomic, and transcriptomic analysis across three ripening stages: green-yellow (GY), light-yellow (LY), and orange-yellow (OY). KEGG enrichment analysis of differentially accumulated metabolites (DAMs) and differentially expressed genes (DEGs) underscored the phenylpropanoid, flavonoid, and anthocyanin biosynthesis pathways as central to the color transition. The results demonstrated that the phenylpropanoid pathway supplied essential precursors, while the transcriptional regulation of core structural genes within the flavonoid pathway directly influenced the color phenotype. Specifically, the transition from GY to LY was driven by the activation of the phenylpropanoid pathway and the coordinated action of chalcone synthase and flavonol synthase (CHS-FLS), leading to increased flavonol accumulation. Subsequently, the shift from LY to OY was characterized by the upregulation of dihydroflavonol 4-reductase (DFR), which redirected metabolic flux toward anthocyanin biosynthesis, supported by a complementary antioxidant system. This study elucidates the stage-specific transcriptional and metabolic programs governing color evolution in R. roxburghii and provides a molecular framework for future fruit quality improvement.

Sclerotinia sclerotiorum is a devastating necrotrophic fungal pathogen that causes stem rot in Brassica crops, leading to substantial yield losses worldwide. This study examines physiological, biochemical, and anatomical differences between susceptible (Varuna) and tolerant (RH1222-28) Brassica juncea cultivars under S. sclerotiorum infection, emphasizing antioxidant and enzymatic defenses. Phenotypic evaluation revealed that while Varuna developed extensive lesions, RH1222-28 exhibited significantly restricted disease symptoms. Varuna had stronger stems, but RH1222-28 coped better with the disease because its biological defenses were strong. RH1222-28 exhibited reinforced cell walls and compact vascular bundles, strengthening its structural resistance. At the same time, it maintained reactive oxygen species (ROS) balance through sustained radical scavenging activity, unlike Varuna, which showed a prolonged oxidative burst and greater tissue damage. These two pathways-structural fortification and ROS homeostasis-emerged as central to RH1222-28's superior tolerance. Principal component and correlation analyses further confirmed that RH1222-28's tolerance is associated with coordinated antioxidant defenses, phenylpropanoid pathway activation, and anatomical fortification, offering valuable insights into mechanisms of resistance against S. sclerotiorum in Brassica juncea.

Nitrogen (N) availability is a key determinant of plant growth and development. Here, we investigate how different N sources shape Arabidopsis thaliana root system architecture, metabolism and hormone dynamics. L-glutamine (L-GLN) significantly enhances root biomass compared to nitrate (KNO₃) without compromising shoot growth. This effect emerges after 2 weeks and is independent of L-GLN's role as a carbon or ammonium source or of potential L-GLN-induced pH changes due to ammonium release, indicating a specific function of L-GLN as a N source and signaling molecule. A reverse genetic screen identified AMINO ACID PERMEASE 1 (AAP1)-mediated uptake and GLUTAMINE SYNTHETASE (GS)-dependent assimilation as essential for L-GLN-induced root biomass. In contrast, the N-sensing regulators NITRATE TRANSPORTER 1.1 (NRT1.1) and AMMONIUM TRANSPORTER (AMT) family members contribute to the differential root responses between KNO₃ and L-GLN. Metabolic profiling revealed distinct amino acid signatures under these N sources, irrespective of genotype. Hormonal analyses showed that L-GLN modulates auxin homeostasis, with auxin supplementation restoring primary root growth and lateral root symmetry under L-GLN conditions. L-GLN also reconfigures cytokinin balance by elevating cZ while reducing tZ, collectively shaping root system architecture through hormone-dependent regulation. Together, these findings establish L-GLN as an integrator of N metabolism and hormone signaling in root development, highlighting its signaling capacity beyond nutrient supply and offering new perspectives for improving N use efficiency.

Anthocyanins, natural pigments prevalent in diverse crops, have garnered substantial interest due to their application in the food, nutraceutical, and cosmetic industries, as well as their potential health benefits. However, the low rate of anthocyanin biosynthesis in most crops limits their large-scale production and utilization. Consequently, elucidating the biosynthetic and transport pathways of anthocyanins, particularly through the identification of key genes and regulatory mechanisms, has become a critical research focus for enhancing anthocyanin production. In this study, we analyze the anthocyanin content across various crops, revealing their widespread presence in plants but with great interspecies variation in concentration. We further evaluate their health benefits, particularly their potential medical applications, such as antidiabetic, anticancer, and anti-inflammatory effects. Additionally, we explore key molecular pathways, including critical enzymes and transcription factors that regulate anthocyanin biosynthesis, intracellular transport, and storage. We systematically review feasible biotechnological strategies to boost anthocyanin yields in crops, such as genetic and metabolic engineering. By synthesizing this knowledge, our study explores key regulatory factors that could optimize anthocyanin biosynthesis efficiency. This work holds promise for advancing their applications in dietary supplementation and therapeutic interventions, ultimately benefiting human health.

Plant growth-promoting rhizobacteria (PGPR) that can break down 1-aminocyclopropane-1-carboxylate (ACC), an ethylene precursor, by ACC deaminase enzymes (ACCd) to reduce ethylene production in plants may enhance plant tolerance to drought stress. This study aimed to identify genes in plant roots regulated by ACCd-bacteria under drought stress and re-watering and to determine major molecular factors and associated metabolic pathways for ACCd bacteria-enhanced drought tolerance and post-stress recovery in creeping bentgrass (Agrostis stolonifera). Transcriptomic analysis was performed in root tissues from plants inoculated with a novel strain of ACCd-producing bacteria, Paraburkholderia aspalathi "WSF23," under well-watered conditions, 35 days of drought stress, and 15 days of re-watering. ACCd bacteria inoculation resulted in differential expression of 53 genes under drought stress. Genes up-regulated in inoculated roots during drought stress included SUMO (small ubiquitin-like modifier) protease OTS1, an alcohol dehydrogenase (ADH2), desiccation-related protein (DRP) gene pcC-13362, cell wall structure and elasticity (TBL27), and antioxidant metabolism (DJ-1C and 1CYSPRXA). For post-drought recovery, inoculated plants differentially expressed 160 genes, including up-regulation of DNA repair (RAD6), signal transduction (WRKY72), root growth and development (D10, WRKY74, ERF3), nitrogen transport (DUR3), and osmoregulation (CIPK23), as well as up-regulation of carotenoid biosynthesis pathways. These findings help to explain the molecular mechanisms associated with ACCd bacteria-mediated drought stress tolerance and post-drought recovery in cool-season perennial grass species, contributing to sustainable methods of reducing water use in turfgrass management.