Physiologia plantarum最新文献

Succulence is a trait that describes water storage in plant organs and tissues regardless of life form. Plants use the stored water to maintain physiological function and delay desiccation. However, it is unclear whether succulence in leaves, stems and roots of woody plants delays desiccation, whether it provides 'utilizable water' to maintain physiological function, or buffers changes in water status in drying soils through capacitance. We conducted a pot dry-down experiment with nine shrub species to determine whether woody plants with greater leaf, stem, or root succulence have greater shoot utilizable water or capacitance. We also investigated whether greater succulence delays desiccation, represented by cumulative VPD, until evapotranspiration ceased or until utilizable water was exhausted. Greater leaf and stem succulence were strongly related to greater shoot utilizable water and capacitance. However, desiccation time was not delayed in plants with greater total shoot succulence, utilizable water, or capacitance. Instead, woody plants with greater root succulence had longer desiccation times. This suggests that woody plants use aboveground succulence to maintain physiological function and water status during drought, whereas root succulence extends desiccation time. Our study improves the mechanistic understanding of how woody plants use stored water to survive in dryland ecosystems.

Water-use efficiency (WUE) is affected by multiple leaf traits, including stomatal morphology. However, the impact of stomatal morphology on WUE across different ontogenetic stages of tree species is not well-documented. Here, we investigated the relationship between stomatal morphology, intrinsic water-use efficiency (iWUE) and leaf carbon isotope ratio (δ¹³C). We sampled 190 individuals, including juvenile and mature trees belonging to 18 temperate broadleaved tree species and 9 genera. We measured guard cell length (GCL), stomatal density (SD), specific leaf area (SLA), iWUE and bulk leaf δ¹³C as a proxy for long-term WUE. Leaf δ¹³C correlated positively with iWUE across species in both juvenile and mature trees, while GCL showed a negative and SD a positive effect on iWUE and leaf δ¹³C. Within species, however, only GCL was significantly associated with iWUE and leaf δ¹³C. SLA had a minor negative influence on iWUE and leaf δ¹³C, but this effect was inconsistent between juvenile and mature trees. We conclude that GCL and SD can be considered functional morphological traits related to the iWUE and leaf δ¹³C of trees, highlighting their potential for rapid phenotyping approaches in ecological studies.

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.

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.

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.

Abiotic stress, including osmotic and salinity stress, significantly affects plant growth and productivity. Copper chaperone for superoxide dismutase (CCS) is essential for copper homeostasis and oxidative stress management. In this study, we investigated the role of the TaCCS1-B gene of bread wheat in enhancing stress tolerance in yeast and transgenic Arabidopsis. Expression of TaCCS1-B increased abiotic stress tolerance in recombinant yeast cells. Phenotypic analysis of Arabidopsis TaCCS1-B expressing lines demonstrated that they exhibited significantly higher germination rates, increased root length and better growth under osmotic and salinity stress than wild type. Additionally, the transgenic lines exhibited higher copper accumulation and enhanced photosynthetic pigments and proline level, coupled with reduced hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) contents. They also showed higher enzymatic antioxidants' activities, indicating reduced oxidative stress in transgenic lines, resulting in reduced flavonoid content. Gene expression analysis indicated modulated expression of stress-responsive genes in the transgenic lines under stress conditions. These findings suggested the role of TaCCS1-B in enhancing stress tolerance by improving copper homeostasis and regulating key stress-responsive genes. This study highlights the potential of TaCCS1-B for the development of better stress resilience crops, which is critical for sustaining agricultural productivity for food security under adverse environmental conditions.

Physiological and molecular mechanisms underpinning plant water stress responses still need deeper investigation. Particularly, the analysis of rootstock-mediated signals represents a complex research field, offering potential applicative perspectives for improving the adaptation of fruit crops to environmental stresses. Nonetheless, fundamental knowledge on this subject needs to be widened, especially in some woody species, including European hazelnut (Corylus avellana L). To fill these gaps, we inspected dynamic changes in gas exchanges and stem water potential of two hazelnut genotypes, the 'San Giovanni' cultivar (SG), the non-suckering rootstock 'Dundee' (D), and their heterograft (SG/D), during a drought stress treatment followed by recovery. Biometric and anatomical traits were measured at the beginning and end of water stress imposition. Additionally, differences in abscisic acid and proline contents were analysed in leaves and roots taken from well-irrigated, stressed and recovered plants, in combination with expression profiles of candidate genes. Grafting with 'Dundee' rootstock positively affected the ability of 'San Giovanni' plants to endure drought by increasing their intrinsic water use efficiency and facilitating post-rehydration recovery. Although anatomical adjustments occurred, we showed that the improved stress adaptation of grafted plants rather depended on biochemical modifications, resulting in increased root proline concentrations and leaf ABA accumulation both during water stress and recovery. We also proved that those metabolic changes were controlled by a differential reprogramming of genes involved in hormone metabolism and stress defence. Grafting with non-suckering rootstocks could therefore represent a promising and environmentally-friendly strategy for improving the adaptability of hazelnut to water deficit.

Melatonin (MT) serves an indispensable function in plant development and their response to abiotic stress. Although numerous drought-tolerance genes have been ascertained in wheat, further investigation into the molecular pathways controlling drought stress tolerance remains necessary. In this investigation, it was observed that MT treatment markedly enhanced drought resistance in wheat by diminishing malondialdehyde (MDA) levels and augmenting the activity of antioxidant enzymes POD, APX, and CAT compared to untreated control plants. Transcriptomic analysis disclosed that melatonin treatment activated the tryptophan metabolism and flavonoid biosynthesis pathways. Furthermore, quantitative reverse transcription PCR (qRT-PCR) outcomes validated that the expression trends of these differentially expressed genes aligned with the transcriptomic data. Metabolomic profiling identified alterations in the abundance of several metabolites, including tryptamine, MT, formylanthranilate, 3-hydroxyanthranilate, 6-hydroxymelatonin, naringenin chalcone, astragalin, pinbanksin, and caffeoyl quinic acid. Co-expression analysis suggested that various transcription factors-encompassing AP2/ERF-ERF, WRKY, bZIP, C2H2, bHLH, NAC, and MYB-participated in controlling the differentially expressed genes across multiple pathways. Ultimately, these findings highlight that exogenous MT application bolsters wheat's drought tolerance through the modulation of tryptophan metabolism and flavonoid biosynthesis. These insights provide novel perspectives on the molecular frameworks mediating MT's effect on drought resistance and pinpointing candidate genes for potential genetic enhancement programs in wheat.