Physiologia plantarum最新文献

Although plant-derived smoke solutions (SSs) have exhibited growth-promoting properties in various plant species, their potential role in mitigating heavy metal stress, specifically in grapevines, has remained unexplored and unreported. This knowledge gap prompted the present study to evaluate the efficacy of foliar application of SSs derived from vineyard pruning waste at concentrations of 0%, 0.5%, 1%, and 2% in mitigating Cadmium (Cd) phytotoxicity in grape saplings. In our study, cadmium stress was induced by applying 10 mg/kg CdCl₂ to the root area of the saplings, in conjunction with fertilizers. Our findings showed that exposure to Cd toxicity impeded the growth of grapevine saplings, adversely affecting shoot and root length, as well as fresh weight. Furthermore, it resulted in a reduction in chlorophyll content, stomatal conductance, and leaf water content while significantly increasing membrane damage and lipid peroxidation. Notably, the application of 0.5% SS enhanced grapevine sapling growth and alleviated Cd stress-induced damage by more effectively regulating physiological and biochemical responses compared to the control and other concentrations. Based on our results, under Cd stress conditions, the application of 0.5% SS effectively increased chlorophyll content, relative water content (RWC), stomatal conductance (1.79 mmol.m^-2.sn^-1), and total phenolic content (1.89 mg.g^-1), whereas it significantly reduced malondialdehyde (MDA) levels and membrane damage (1.35 nmol.g^-1). Additionally, it significantly elevated the activities of antioxidant enzymes, including superoxide dismutase (SOD) (2.16 U.mg^-1), catalase (CAT) (1.55 U.mg^-1), and ascorbate peroxidase (APX) (3.03 U.mg^-1). The study demonstrated that plant-derived SS mitigates Cd stress in grapevines by enhancing antioxidative defence mechanisms.

The worldwide cultivated Cucurbita pepo L. is one of the most diverse species in the plant kingdom. In this study, chilling tolerance over a wide range of cultivars was characterized to discover the allelic variants to improving the postharvest quality of the immature fruit during cold storage. For this purpose, fruits from 126 accessions of worldwide origin have been evaluated for weight loss and chilling injury after 3, 7 and 14 days of cold storage, classifying them into tolerant, partially tolerant, and sensitive accessions. To verify this classification, antioxidant capacity and lipid peroxidation (MDA) of contrasting accessions (tolerant vs. sensitive) were assessed. The antioxidant capacity significantly decreased during cold storage in the sensitive accessions, while it was maintained in tolerant accessions. Additionally, the sensitive accessions presented a higher accumulation of MDA during this period. Finally, a GWAS analysis using GBS data available in CuGenDBv2, combined with weight loss percentage data, led to the identification of a candidate QTL located on chromosome 17 that regulates postharvest cold tolerance in zucchini. The region contains four SNPs whose alternative alleles were significantly associated with lower weight loss percentage and chilling injury indices during cold storage. Two SNPs are located in the 3' UTR region of the gene CpERS1, a gene involved in ethylene perception. The other two SNPs generate missense mutations in the coding region of a Pectin methyl esterase inhibitor gene (CpPMI). The role of this QTL and these variants in chilling tolerance is discussed.

SNF1-RELATED KINASE 2 (SnRK2) plays a crucial role in plants' stress response. Although studies have reported that the overexpression of several SnRK2 family members in different plants leads to improved stress tolerance, it is difficult to elucidate the mechanisms by which SnRK2s regulate stress tolerance due to the variability of experimental variables in these studies. Therefore, we used meta-analysis to comprehensively analyze 22 parameters that can reflect drought tolerance and salinity tolerance in SnRK2s-transformed plants and to explore the effects that different experimental variables between studies have on the relevant plant parameters. The results showed that the overexpression of SnRK2s mainly improved plants' drought and salinity tolerance by reducing their osmotic stress and oxidative damage, improving photosynthesis and other biochemical and physiological processes. Out of the 22 physiological parameters, 17 and 19 were significantly affected by drought and salt stress, respectively, and 10 indicators were also significantly changed under non-stress conditions. Under salt stress, the cell membrane permeability among these parameters shows the most significant changes, increasing by 506.57% in SnRK2-overexpressing plants compared to wild type (WT). Therefore, although plants overexpressing SnRK2s respond positively to both drought and salt stress, they demonstrated greater tolerance to salt stress. In addition, among the detected regulatory variables, donor-acceptor type, promoter type, stress type, experimental medium, and duration all affected the extent of SnRK2s overexpression and affected the physiological characteristics of the transgenic plants. Also, different stress conditions (salt, drought stress) led to different degrees of transformation. These studies provide new research directions for studying crop stress tolerance and help to better explore the functions played by SnRK2s in external plant stresses.

Increasing CO₂ availability is a common practice at the industrial level to trigger biomass productivity in microalgae cultures. Still, the consequences of high CO₂ availability in microalgal cells exposed to relatively high light require further investigation. Here, the photosynthetic, physiologic, and metabolic responses of the green microalga model Chlamydomonas reinhardtii were investigated in high or low CO₂ availability conditions: high CO₂ enabled higher biomass yields only if sufficient light energy was provided. Moreover, cells grown in high light and high CO₂ availability were characterized, compared to cells grown in high light and low CO₂, by a relative increase of the energy-dense triacylglycerols and decreased starch accumulation per dry weight. The photosynthetic machinery adapted to the increased carbon availability, modulating Photosystem II light-harvesting efficiency and increasing Photosystem I photochemical activity, which shifted from being acceptor side to donor side limited: cells grown at high CO₂ availability were characterized by increased photosynthetic linear electron flow and by the onset of a balance between NAD(P)H oxidation and NAD(P)⁺ reduction. Mitochondrial respiration was also influenced by the conditions herein applied, with reduced respiration through the cytochrome pathway compensated by increased respiration through alternative pathways, demonstrating a different use of the cellular reducing power based on carbon availability. The results suggest that at high CO₂ availability and high irradiance, the reducing power generated by the oxidative metabolism of photosynthates is either dissipated through alternative oxidative pathways in the mitochondria or translocated back to the chloroplasts to support carbon assimilation and energy-rich lipids accumulation.

Anthocyanins are important secondary metabolites in plants. After the formation of anthocyanidins, Flavonoid 3-O-glucosyltransferase (3GT) mediated glycosylation first occurs at the C-3 site, forming a stable anthocyanin 3-O-glucoside. Several studies have investigated the function of 3GT using biochemical methods. However, it is necessary to provide further genetic evidence for the role of Ph3GT in petunia (Petunia hybrida). In addition, there is no information regarding the subcellular localization of Ph3GT and the regulation of transcription factors on Ph3GT. In this study, the full-length Ph3GT gene from petunia (Petunia hybrida) was isolated. We found that Ph3GT is localized in the cytoplasm. Ph3GT exhibited high expression levels in the corollas during the coloring period of petunia flowers. VIGS-mediated Ph3GT silencing resulted in a lighter corolla color and a significant decrease in the anthocyanin content in six petunia cultivars. The silencing of Ph3GT affected the expression levels of eight key genes in the anthocyanin synthesis pathway. Additionally, dual luciferase and yeast one-hybrid assays showed that R2R3-MYB transcription factor PhAN2 directly regulates the transcript of Ph3GT.

This study investigates how variations in diurnal temperature and phosphorus concentration affect the growth of native Artemisia argyi and invasive Solidago canadensis under intraspecific and interspecific competition. We conducted factorial experiments to assess the impacts of warming, including an increased diurnal temperature range (DTRinc), a symmetric increase in diurnal temperature range (DTRsys), a decreased diurnal temperature range (DTRdec) and phosphorus application (5 g and 10 g P m² yr^-1) on both intra- and inter-specific competition among plants. The results indicated that (1) the DTRsys for A. argyi was -48.95% and for S. canadensis, it was -31.49% and overall had a more pronounced inhibitory effect on the biomass of both plant species than other warming treatments after comprehensive analysis. (2) Under intraspecific competition, phosphorus promoted the growth of A. argyi and S. canadensis on plant height, root length, and biomass. The biomass of A. argyi (22.75% and 53.61%) and S. canadensis (11.49% and 27.76%) increased under low and high phosphorus, respectively. Under interspecific competition, the plant height and biomass of the two plant species showed different response trends to phosphorus. Still, the competitiveness of S. canadensis increased compared with the untreated group. (3) Plant adaptability in biomass was more sensitive to warming than phosphorus treatments, and warming reduced the promoting effect of phosphorus, indicating that warming and phosphorus have interactive effects on plants. Phosphorus exacerbated the inhibitory effect of DTRinc on the biomass of S. canadensis, which was more pronounced than other warming methods. The different responses of the two plants mention the species to warming and phosphorus treatments under different competition scenarios reflect the differences in their ecological strategies for adapting to the environment.

In the green approach for nanoparticle synthesis, biomolecules like phenols, alkaloids, proteins, enzymes, and lipids are the prime reducing and stabilizing agents. In this study, we reported the synthesis of silver nanoparticles (AgNPs) using the aqueous extract of the marine algae Iyengaria stellata (Børgesen) for the first time. The characterization study showed that the developed AgNPs were spherical in shape and their average particle size was 60 nm. The UV-visible spectrum of AgNPs showed strong surface plasmon resonance (SPR) near 425 nm, whereas the Fourier transform infrared spectroscopy (FTIR) spectrum revealed the presence of several functional groups like amines, nitriles, hydroxyl, and carbonyl groups on the nanoparticle surface, which confirms the involvement of algal metabolites in the reduction and stabilization of AgNPs. The X-ray diffraction (XRD) analysis provided information about the crystallinity of developed nanoparticles, and the crystallite size of AgNPs was calculated to be 33 nm using the Scherrer equation. The algal synthesized AgNPs examined for their impact on growth of tomato seeds under salt stressed conditions showed significant enhancement in growth parameters like leaf area, shoot height, root length, shoot weight, and root weight. Also, a reduction in biochemical stress responses such as chlorophyll content, relative water content, electrolyte leakage, hydrogen peroxide (H₂O₂) content, glycine betaine content, and proline content was seen. This study suggests that algal synthesized AgNPs can reduce the effect of salt stress in tomato plants and promote their overall growth.

Sugars, produced through photosynthesis, are at the core of all organic compounds synthesized and used for plant growth and their response to environmental changes. Their production, transport, and utilization are highly regulated and integrated throughout the plant life cycle. The maintenance of sugar partitioning between the different subcellular compartments and between cells is important in adjusting the photosynthesis performance and response to abiotic constraints. We investigated the consequences of the disruption of four genes coding for SWEET sugar transporters in Arabidopsis (SWEET11, SWEET12, SWEET16, and SWEET17) on plant photosynthesis and the response to drought. Our results show that mutations in both SWEET11 and SWEET12 genes lead to an increase of cytosolic sugars in mesophyll cells and phloem parenchyma cells, which impacts several photosynthesis-related parameters. Further, our results suggest that in the swt11swt12 double mutant, the sucrose-induced feedback mechanism on stomatal closure is poorly efficient. On the other hand, changes in fructose partitioning in mesophyll and vascular cells, measured in the swt16swt17 double mutant, positively impact gas exchanges, probably through an increased starch synthesis together with higher vacuolar sugar storage. Finally, we propose that the impaired sugar partitioning, rather than the total amount of sugars observed in the quadruple mutant, is responsible for the enhanced sensitivity upon drought. This work highlights the importance of considering SWEET-mediated sugar partitioning rather than global sugar content in photosynthesis performance and plant response to drought. Such knowledge will pave the way to design new strategies to maintain plant productivity in a challenging environment.

The multidimensional significance of metabolomics has gained increasing attention in oilseeds research and development. Sesame, peanut, soybean, sunflower, rapeseed, and perilla are the most important oilseed crops consumed as vegetable oils worldwide. However, multiple biotic and abiotic stressors affect metabolites essential for plant growth, development, and ecological adaptation, resulting in reduced productivity and quality. Stressors can result in dynamic changes in oilseed crops' overall performance, leading to changes in primary (ex: saccharides, lipids, organic acids, amino acids, vitamins, phytohormones, and nucleotides) and secondary (ex: flavonoids, alkaloids, phenolic acids, terpenoids, coumarins, and lignans) major metabolite classes. Those metabolites indicate plant physiological conditions and adaptation strategies to diverse biotic and abiotic stressors. Advancements in targeted and untargeted detection and quantification approaches and technologies aided metabolomics and crop improvement. This review seeks to clarify the metabolomics advancements, significant contributions of metabolites, and specific metabolites that accumulate in reaction to various stressors in oilseed crops. Considering the response of metabolites to multiple stress effects, we compiled comprehensive and combined metabolic biosynthesis pathways for six major classes. Understanding these essential metabolites and pathways can inform molecular breeding strategies to develop resilient oilseed cultivars. Hence, this review highlights metabolomics advancements and metabolites' potential roles in major oilseed crops' biotic and abiotic stress responses.

Plants are central to global food production, and the pursuit of sustainability aims to enhance or preserve food quality while safeguarding the environment. Due to their immobility, plants are unable to evade unfavourable climatic setups or interactions with other living creatures. Upon their interaction with insect herbivores, plants face biotic stress, which is a constant challenge for plants, causing molecular, physiological, and biochemical changes and reducing their productivity. To combat biotic stress caused by herbivores, plants have evolved intricate defence mechanisms through growth regulators such as auxins, cytokinins, gibberellins, salicylic acid (SA), jasmonic acid (JA), ethylene (ET), abscisic acid (ABA), strigolactones and brassinosteroids. The intricate network of specific proteins, metabolites and certain phytohormones orchestrates plant defensive reactions, leading to their skilful coordination in responding to insect attacks. Comprehending the defence mechanisms holds the key to mitigating significant crop and economic losses. This review entails a comprehensive analysis of the role of growth regulators in enhancing plant immunity against herbivory, highlighting the substantial efforts by the scientific community to manage and mitigate damages from biotic stress in plants, ultimately contributing to the advancement of sustainable agriculture.