Physiologia plantarum最新文献

As a member of the sucrose transporter (SUT) family, AtSUT4 occupies a distinct evolutionary category, implying unique functional specialization. However, studies on its involvement in growth and development regulation remain limited. Here, we demonstrated that AtSUT4 overexpression significantly inhibited root growth in Arabidopsis thaliana. Analyses using bromocresol purple indicators and non-invasive micro-test technology (NMT) revealed that AtSUT4 overexpression induced proton influx in the root apical meristem and elongation zones, while suppressing AHA1/AHA2 expression, ultimately resulting in an increased proton influx and extracellular alkalization of root tissues. Treatment with the H⁺-ATPase activator fusicoccin (FC) and the inhibitor N, N'-dicyclohexylcarbodiimide (DCCD) indicated that AHA negatively regulated AtPIN2 expression. Consequently, overexpression of AtSUT4 down-regulated AHA expression while promoting AtPIN2 expression and auxin accumulation in the root tips. Transcriptomic profiling further linked disrupted proton homeostasis and auxin accumulation to mark the down-regulation of genes encoding ribosomal proteins, tubulins, and pectin degradation enzymes. These findings suggested that AtSUT4-induced rhizosphere pH shifts and auxin perturbations concurrently impaired expansion forces (via cytoskeletal proteins) and enhanced limiting forces (via cell wall rigidity). Herein, we tentatively propose that AtSUT4 overexpression induced proton influx, which concurrently suppressed AHA1/2 expression and enhanced AtPIN2 transcription. This cascade culminated in rhizosphere alkalinization and variation of auxin distribution, collectively disrupting root cell growth. Our findings potentially established a previously unrecognized regulatory nexus between sugar signaling and auxin-mediated developmental pathways in Arabidopsis thaliana.

Quinoa is a facultative halophyte capable of thriving in harsh environmental conditions. Its epidermal bladder cells (EBCs) have been suggested to play a key role in salinity tolerance. To clarify their importance, several experiments have been conducted to assess the effects of EBC removal. However, existing studies have yielded conflicting evidence, both supporting and rejecting their significance. Notably, most of these investigations have focused on leaf EBCs, despite the fact that quinoa accumulates more ions in the stem than in the leaves. To address this gap, we designed a manipulative experiment to remove EBCs from the leaves and stems. Our results demonstrate that stem EBCs is crucial under both saline and non-saline conditions. Their removal led to reduced growth and transpiration in non-saline environments and decreased shoot biomass and Na⁺ accumulation in the shoot under saline conditions, while the removal of leaf EBCs did not alter the growth under either non-saline or saline conditions. Based on these findings, we hypothesize that stem EBCs play a role in ion homeostasis and water movement.

Soil and irrigation salinity continue to have a major impact on the world's agriculture and horticulture, and loss of plant production is likely to worsen with global warming and climate change. Efforts to mitigate salinity stress and breed better salt-tolerant plants rely on our knowledge of plant response to abiotic stress at the physiological and molecular levels. Salinity usually leads to the accumulation of free and conjugated polyamines (PAs) in plant tissues. Putrescine (Put), and its derivatives spermine (Spm) and spermidine (Spd), perform critical functions by activating biochemical, physiological and molecular defense systems, thus reducing damage caused by salinity stress. Promoting endogenous levels of PAs can improve the salt tolerance of plants. Furthermore, the application of exogenous PAs has been shown to effectively mitigate salt stress across a range of commercially important plant species. This review critically examines the biosynthesis of PAs and their associated physiological, phytochemical, and molecular responses in plants under saline conditions. In addition, it evaluates the potential of PAs as a strategic tool for enhancing salinity tolerance. The review also highlights key gaps in current knowledge and proposes directions for future research to optimize the use of PAs in salinity stress management.

Coptis chinensis Franch., a traditional Chinese medicine (TCM), exhibits pharmacological effects including antipyretic and analgesic, anti-arrhythmic and anti-tumor. Alternative splicing (AS) significantly impacts plant growth, development, and biosynthesis, yet its role in C. chinensis remains poorly understood. This study used transcriptome sequencing to analyze and identify AS events in this species. Functional annotation and enrichment analysis of these AS genes were conducted. Moreover, we screened the key environmental variables that affect the growth of C. chinensis using the Biomod2 model and designed stress experiments to further validate AS events and their regulatory effects on this plant. Two types of AS events were identified: skipped exon (SE) and mutually exclusive exons (MXE), with SE-type being predominant. These AS genes were enriched in 189 Gene Ontology and 59 Kyoto Encyclopedia of Genes and Genomes entries. These included entries related to environmental adaptations, such as "response to heat," "protein phosphorylation," "starch and sucrose metabolism," and five entries related to benzylisoquinoline alkaloid biosynthesis. Biomod2 model results showed that Temperature Seasonality (Bio4) was the environmental variable with the highest contribution (45.58%). Additional validation experiments revealed that the splicing index value of the AS genes in C. chinensis exhibited an initial increase followed by a decrease with the extension of the heat stress time, while gene expression also generally increased. This study highlights the crucial role of AS in the environmental adaptation and benzylisoquinoline alkaloid biosynthesis of C. chinensis, providing a theoretical basis for the cultivation and improvement of the varieties of this TCM.

Overuse of pesticides often poses a severe threat to agricultural productivity. In vitro experiments were conducted to assess the effect of different concentrations (10, 20, 40, 80, and 100 μg mL^-1) of chlorpyrifos (CP) and imidacloprid (IMD) on germination, physiology, and cellular properties of lettuce (Lactuca sativa). The 100 μg mL^-1 dose greatly reduced germination attributes, length, and seedling survival. At 100 μg mL^-1, CP and IMD decreased seed germination (80% and 60%), vigor indices (76.7% and 65.3%), survival (79.5% and 65.5%), and tolerance indices (83.3% and 62.5%) as compared to control. Insecticide-exposed roots showed cracks/fractures, disintegration, and distortion over control roots, thus exhibiting the toxic potential of insecticides. Elevated CP and IMD concentrations led to increased oxidative stress and the generation of reactive oxygen species (ROS) in lettuce seedlings. When subjected to 100 μg mL^-1 of CP and IMD, seedlings exhibited a significant (p ≤ 0.05) increase in levels of hydrogen peroxide (70.2% and 56.8%), superoxide radicals (88.9% and 70.5%), electrolyte leakage (87.9% and 66.4%), and malondialdehyde (94.5% and 61.4%). Furthermore, insecticide dose-dependent declines in adenosine triphosphate (ATP) content and respiration efficiency (RE) were observed in seedlings. Antioxidant enzymes' activity in lettuce was modulated by exogenous insecticide treatments. Secondary metabolites and antioxidant activities were altered in lettuce under insecticide stress. Both insecticides imparted phytotoxic effects that highlight the importance of their optimal utilization in soil-plant systems and their careful monitoring in soils. There is an urgent need to develop slow-release and target-specific pesticide formulations that ensure effective crop protection while safeguarding soil health.

Cadmium (Cd) contamination in agricultural soils poses a major threat to soil health and crop productivity. This study aimed to evaluate the potential of Bacillus subtilis (BSS) in alleviating Cd-induced stress in maize by improving soil nutrients, modulating microbial communities, reducing Cd accumulation, and enhancing plant growth and nutrient uptake. It is hypothesized that rhizospheric B. subtilis will enhance nitrogen metabolism, restore soil nutrients, improve microbes, and reduce Cd uptake in maize. A pot experiment was conducted comprising six treatments, including control, BSS (B. subtilis), Cd25 (25 mg kg^-1), Cd25BSS, Cd50 (50 mg kg^-1), and Cd50BSS. Soil properties, enzymatic activities, Cd accumulation, microbial diversity, and ionomic profiles in various maize tissues were analyzed. Application of B. subtilis significantly improved soil nutrient availability, particularly nitrogen (N), phosphorus (P), and potassium (K) under Cd stress. B. subtilis reduced Cd accumulation in maize roots by 58.0% and limited translocation to shoots and grains by 66% and 54.2%, respectively. The health risk index declined by 53.7%. B. subtilis enhanced microbial diversity, increasing the abundance of beneficial phyla such as Pseudomonadota, Bacillati, Chloroflexota, and Myxococcota. Plant biomass and enzymatic activities (nitrate reductase, urease, and glutamine synthetase) improved significantly. Ionome analysis showed significant increases in grain N, P, and K contents by 90.3%, 9.4%, and 8.0%, respectively. Additionally, Acidobacteriota, Actinomycetota, and Bacillati were positively correlated with soil nutrients. B. subtilis effectively mitigates Cd toxicity in maize by enhancing soil health, modulating microbial communities, improving nutrient cycling, and reducing Cd bioaccumulation. These findings support its application as a sustainable biotechnological strategy for remediating Cd-contaminated soils and improving crop productivity.

Eukaryotic phototrophs depend on the activity of two engines (the plastid and the mitochondrion) to generate the energy required for cellular metabolism. Because of their overlapping functions, both activities must be closely coordinated. At the plastid level, optimisation occurs through alternative electron transport, the diversion of excess electrons from the linear transport chain and metabolic exchanges. A similar process takes place in the mitochondria, with documented evidence of energy and redox equivalents being exchanged between the two organelles. Organelle-organelle energy interactions at the physiological level are well established in diatoms, an ecologically significant member of phytoplankton. Yet the molecular components involved in this process remain largely unknown. Here, we identify a mitochondrial carrier family (MCF) transporter, MCFc, located at the plastid envelope of Phaeodactylum tricornutum, which seems to be widely distributed in complex algae. We then compare the performance of a wild-type and a mutant lacking MCFc. An analysis of spectroscopic and oxygen exchange data unveiled altered energetic interactions in the mutant, suggesting that MCFc plays a role in plastid-mitochondrion communication. In silico analysis of MCFc implies a similar substrate-specific model to that of ADP/ATP carriers, although distinct motif differences in MCFc indicate potential variations in its function, with possible substrates including arginine, aspartate/glutamate or citrate/isocitrate. Together, these findings support a role for mitochondrial energy metabolism in sustaining diatom photosynthesis, likely mediated by MCFc, though further investigation is needed to determine the precise mechanism.

Climate warming has led to an increase of drought events with consequences on physiological processes in trees and implications for carbon sequestration. Drought may lead to changes in the timing of autumn phenology and premature senescence. However, mechanisms linking physiological responses to drought stress and changes in phenological events in tree species remain poorly understood. We investigated how drought impacts autumn phenology and the timing of leaf senescence in three temperate tree species, along with the associated physiological responses. For this purpose, we designed a factorial field experiment with the evergreen species white pine, and two deciduous species, red maple and white oak, and used rainout structures to reduce ~50% of precipitation in drought-stressed plots compared to watered control plots. To assess drought impacts on autumn phenology and senescence we measured growth, photosynthesis, and leaf spectral reflectance. Drought-stressed deciduous seedlings exhibited premature senescence compared to controls. Water deficit during the growing season also decreased photosynthetic rates, height growth and biomass accumulation. The photochemical reflectance index effectively captured drought-induced changes in leaf physiology and phenology in white pine and the chlorophyll carotenoid index tracked the seasonality in deciduous trees, demonstrating that carotenoid-based vegetation indices are promising tools for monitoring drought stress responses in temperate forests.

The melon fruit shape is a trait that influences storage as well as consumer preference. Fruit shape is known to be regulated by factors such as Ovate Family Proteins (OFPs), Tonneau Recruiting Motif proteins (TRMs), IQ67 domain proteins (IQDs) and plant hormones. CmOFP13 (MELO3C025206) had been identified as a regulator of shape in melon using a map-based cloning approach and validated by overexpression in Arabidopsis, generating plants with rounder leaves and shorter siliques. In this work, CRISPR-Cas9 was applied in melon for the functional validation of CmOFP13. 'Védrantais' (VED) seed cotyledons were transformed, obtaining diploid edited plants with a slightly elongated phenotype compared to the wild type in both ovaries and fruits. This effect is associated with the presence of larger cells in the distal area of E1 stage flowers. The analysis of the mutation indicated the loss of the OVATE domain in the edited CmOFP13, while maintaining the DNA-binding domain. In addition, new candidate genes have been proposed based on phylogenetic analyses and expression data. The mutation of OFPs offers the possibility of new melon fruit shapes, adapting the fruit for safer storage or to consumer demands.

Canola exemplifies the transformation of a crop from industrial use to a globally significant edible oilseed through sustained genetic and biotechnological innovation. Historically, rapeseed was characterized by high erucic acid and glucosinolate contents, restricting its use primarily to industrial applications. However, classical breeding efforts in the 1970s successfully developed 'double-low' canola varieties, significantly reducing erucic acid and glucosinolate levels, thus establishing canola as a safe and nutritious food-grade oil. Subsequent advancements, including the introduction of hybrid cultivars, markedly enhanced seed yields, while mutation breeding and marker-assisted selection refined key agronomic traits such as lodging tolerance and disease resistance. Later, biotechnology breakthroughs expanded canola's versatility, leading to specialty oils with tailored fatty-acid profiles, for example, high-laurate oils for industrial applications and omega-3 enriched oils for nutritional purposes, as well as herbicide-tolerant cultivars that simplified weed management. More recently, genome-editing technologies, notably CRISPR/Cas9, have accelerated trait improvement by precisely modifying oil composition and significantly enhancing pod shatter resistance. This review synthesizes major genetic and breeding milestones that collectively shaped modern canola, highlights ongoing challenges associated with its complex polyploid genome, and discusses how emerging approaches, including multi-omics integration, precision genome editing, and artificial intelligence, offer promising strategies to further enhance canola productivity and sustainability.