Physiologia plantarum最新文献

The Ziziphus genus, belonging to the Rhamnaceae family, holds significant economic, nutritional, and medicinal value. However, much remains to be discovered about its diversity and physical characteristics. Factors such as growth, resilience to changes, disease resistance, and unique features contribute to the quality of Ziziphus species. This study aims to investigate the genomes of 200 genotypes from five Ziziphus species: Ziziphus jujuba (Zj), Ziziphus nummularia (Zm), Ziziphus oxyphylla (Zx), Ziziphus mauritiana (Zm), and the cultivated variety Ziziphus jujube var. jujube, collected from Pakistan and China. Our goal is to identify single nucleotide polymorphisms (SNPs) associated with eight different traits and understand the genetic diversity within the selected Ziziphus species and their genotypes. Using high-quality SNPs obtained through genotype-by-sequencing (GBS), we conducted population structure, phylogenetic, and principal coordinates analyses, identifying a total of 10,945 clean SNPs. These genotypes were categorized into two groups, A and B. Natural Ziziphus variants in Pakistan, specifically Z. jujuba and Z. nummularia, exhibited high levels of genetic diversity and polymorphic information content (PIC) of 0.46 and 0.41, respectively, compared to other species. Furthermore, we identified 15 influential candidate genes that play crucial roles in regulating agronomic traits, such as fruit width and diameter, leaf width, plant height, and stem diameter within this group. This study provides valuable insights that can be utilized in Ziziphus breeding efforts.

Drought represents the predominant and most critical abiotic stress challenge within the domain of viticulture, necessitating the identification and application of efficacious strategies to ameliorate its deleterious effects. In the contemporary realm of abiotic stress management, the deployment of α-lipoic acid (α-Lipo), known for its antioxidant capabilities, as an exogenous treatment has been investigated for mitigating various abiotic stresses in numerous plant species, yet a detailed exploration of its efficacy in alleviating drought stress in grapevines remains to be conclusively determined. This study aimed to elucidate the adaptive mechanisms against drought stress by examining the effects of different α-Lipo concentrations (0, 1, 25 and 50 μM) applied on the foliar under well-irrigated and drought conditions on American grapevine rootstocks '1103 P' (drought tolerant) and '3309 C' (drought sensitive). Our findings revealed that the efficacy of α-Lipo varied significantly depending on rootstock type and irrigation status. 1103 P rootstock treated with 1 μM α-Lipo under well-irrigated conditions showed greater positive effects on growth traits, photosynthetic and osmotic parameters. In contrast, in rootstock 3309 C under the same conditions, the highest effects were obtained at 25 and 50 μM α-Lipo concentrations. Under drought stress conditions, 50 μM α-Lipo treatment improved physiological parameters (chlorophyll content, proportional water coverage and stomatal conductance), proline content and antioxidant enzyme activities (SOD, CAT and APX), while reducing electrolyte leakage and MDA levels in both rootstocks, showing a strong potential to increase oxidative stress tolerance and sustain plant growth. Heatmap visualization analysis confirmed the data obtained from Principal Component Analysis (PCA) and revealed that 1103 P treated with 50 μM α-Lipo under drought stress conditions exhibited superior physiological performance compared to 3309 C under the same conditions. This indicates the importance of potential rootstock differences in stress adaptation or α-Lipo uptake efficiency. These findings suggest that α-Lipo holds promise as an eco-friendly, natural bio-stimulant for use in arid environments, contributing to the advancement of sustainable agricultural practices in the foreseeable future.

Salinity is considered one of the abiotic stresses that have the greatest impact on soybean production worldwide. Lanthanum (La) is a rare earth element that can reduce adverse conditions on plant growth and productivity. However, the regulatory mechanism of La-mediated plant response to salt stress has been poorly studied, particularly in soybeans. Therefore, our study investigated the mechanisms of La-mediated salt stress alleviation from the perspectives of the antioxidant system, subcellular structure, and metabolomics responses. The results indicated that salt stress altered plant morphology and biomass, resulting in an increase in peroxidation, inhibition of photosynthesis, and damage to leaf structure. Exogenous La application effectively promoted the activity of superoxide dismutase (SOD) and peroxidase (POD), as well as the soluble protein content, while decreasing the Na⁺ content and Na⁺/K⁺ ratio in roots and leaves, and reducing oxidative damage. Moreover, transmission electron microscopy (TEM) demonstrated that La prevented the disintegration of chloroplasts. Fourier-transform infrared spectroscopy (FTIR) analysis further confirmed that La addition mitigated the decline in protein, carbohydrates, and pectin levels in the leaves. Lanthanum decreased the leaf flavonoid content and synthesis by inhibiting the content of key substances in the phenylalanine metabolism pathway during NaCl exposure. Collectively, our research indicates that La reduces cell damage by regulating the antioxidant system and secondary metabolite synthesis, which are important mechanisms for the adaptive response of soybean leaves, thereby improving the salt tolerance of soybeans.

Anthocyanin is a type of plant secondary metabolite beneficial to human health. The anthocyanin content of vegetable and fruit crops signifies their nutritional quality. However, the molecular mechanism of anthocyanin accumulation, especially tissue-specific accumulation, in Caitai, as well as in other Brassica rapa varieties, remains elusive. In the present study, taking advantage of three kinds of Caitai cultivars with diverse colour traits between leaves and stems, we conducted a comparative transcriptome analysis and identified the molecular pathway of anthocyanin biosynthesis in Caitai leaves and stems, respectively. Our further investigations demonstrate that bHLH42, which is robustly induced by MeJA, closely correlates with tissue-specific accumulation of anthocyanins in Caitai; bHLH42 upregulates the expression of flavonoid/anthocyanin biosynthetic pathway genes to activate anthocyanin biosynthesis pathway, importantly, overexpression of bHLH42 significantly improves the anthocyanin content of Caitai. Our analysis convincingly suggests that bHLH42 induced by jasmonic acid signalling plays a crucial role in tissue-specific accumulation of anthocyanins in Caitai.

Climate change is bringing more frequent and intense droughts, reducing overall water availability and adversely affecting crops. There is a need to improve our understanding of the tissular and cellular adaptation mechanisms that are critical for plant water conservation strategies. Here, we have used NMR relaxometry in combination with microscopy and multi-omic analysis to study the effects of progressive soil drought on winter oilseed rape (WOSR, Brassica napus L., cv. Aviso) leaves. This study reveals the structural and metabolic adjustments these leaves operate to maintain cell homeostasis. Our results are original in showing that the adaptive responses are altered in leaves at the onset of senescence, associated with changes in metabolic plasticity and mesophyll structures. Thus, long-term responses in young leaves involving osmotic adjustment were combined with the maintenance of tissue hydration and cell growth, contributing to high survival and recovery capacity. For the first time, short-term responses observed in early senescent-old leaves were associated with early drought-induced dehydration of the spongy layer. However, this dehydration was not followed by osmotic adjustment and did not allow maintenance of leaf tissue turgor. These findings open further studies on the genetic variability of drought responses related to identified short- and long-term structural and metabolic plasticity traits in Brassica species.

Plant infections caused by fungi lead to significant crop losses worldwide every year. This study aims to better understand the plant defence mechanisms regulated by red light, in particular, the effects of red light at night when most phytopathogens are highly infectious. Our results showed that superoxide production significantly increased immediately after red light exposure and, together with hydrogen peroxide levels, was highest at dawn after 30 min of nocturnal red-light treatment. In parallel, red-light-induced expression and increased the activities of several antioxidant enzymes. The nocturnal red light did not affect salicylic acid but increased jasmonic acid levels immediately after illumination, whereas abscisic acid levels increased 3 h after nocturnal red-light exposure at dawn. Based on the RNAseq data, red light immediately increased the transcription of several chloroplastic chlorophyll a-b binding protein and circadian rhythm-related genes, such as Constans 1, CONSTANS interacting protein 1 and zinc finger protein CONSTANS-LIKE 10. In addition, the levels of several transcription factors were also increased after red light exposure, such as the DOF zinc finger protein and a MYB transcription factor involved in the regulation of circadian rhythms and defence responses in tomato. In addition to identifying these key transcription factors in tomato, the application of red light at night for one week not only reactivated key antioxidant enzymes at the gene and enzyme activity level at dawn but also contributed to a more efficient and successful defence against Botrytis cinerea infection.

Worldwide, where the demand for novel and greener solutions for sustainable agricultural production is increasing, the use of eco-friendly products such as seaweed-derived biostimulants as pre-sowing treatment represent a promising and important approach for the future. Cystoseira barbata, a brown seaweed species abundant in the Mediterranean Region, was collected from the Marmara Sea and subjected to water, alkali, and acidic extractions, and the biostimulant activity of these extracts was tested on wheat (Triticum durum cv. Saricanak-98) using different rates through application to the seeds or germination medium (substrate) applications. The different extracts were characterized by mineral, total phenolic, free amino acid, mannitol, polysaccharide, antioxidant concentrations and hormone-like activity. The effects of the extracts on growth parameters, root morphology, esterase activity, and mineral nutrient concentrations of wheat seedlings were investigated. Our results suggest that the substrate application was more effective in enhancing the seedling performance compared to the seed treatment. High rates of seaweed extracts applied to substrates increased the shoot length and fresh weight of wheat seedlings by up to 20 and 25%, respectively. The substrate applications enhanced the root fresh weights of wheat seedlings by up to 25% when compared to control plants. Among the biostimulant extract applications, the water extract at the highest rate yielded the most promising results in terms of the measured parameters. Cystoseira barbata extracts with different compositions can be used as effective biostimulants to boost seedling growth. The local seaweed biomass affected by mucilage problems, has great potential as a bioeconomy resource and can contribute to sustainable practices for agriculture.

In light of the changing climate that jeopardizes future food security, genomic selection is emerging as a valuable tool for breeders to enhance genetic gains and introduce high-yielding varieties. However, predicting grain yield is challenging due to the genetic and physiological complexities involved and the effect of genetic-by-environment interactions on prediction accuracy. We utilized a chained model approach to address these challenges, breaking down the complex prediction task into simpler steps. A diversity panel with a narrow phenological range was phenotyped across three Mediterranean environments for various morpho-physiological and yield-related traits. The results indicated that a multi-environment model outperformed a single-environment model in prediction accuracy for most traits. However, prediction accuracy for grain yield was not improved. Thus, in an attempt to ameliorate the grain yield prediction accuracy, we integrated a spectral estimation of spike number, being a major wheat yield component, with genomic data. A machine learning approach was used for spike number estimation from canopy hyperspectral reflectance captured by an unmanned aerial vehicle. The spectral-based estimated spike number was utilized as a secondary trait in a multi-trait genomic selection, significantly improving grain yield prediction accuracy. Moreover, the ability to predict the spike number based on data from previous seasons implies that it could be applied to new trials at various scales, even in small plot sizes. Overall, we demonstrate here that incorporating a novel spectral-genomic chain-model workflow, which utilizes spectral-based phenotypes as a secondary trait, improves the predictive accuracy of wheat grain yield.

Approximately 60% of the genes and gene products in the model species Arabidopsis thaliana have been functionally characterized. In non-model plant species, the functional annotation of the gene space is largely based on homology, with the assumption that genes with shared common ancestry have conserved functions. However, the wide variety in possible morphological, physiological, and ecological differences between plant species gives rise to many species- and clade-specific genes, for which this transfer of knowledge is not possible. Other complications, such as difficulties with genetic transformation, the absence of large-scale mutagenesis methods, and long generation times, further lead to the slow characterization of genes in non-model species. Here, we discuss different resources that integrate plant gene function information. Different approaches that support the functional annotation of gene products, based on orthology or network biology, are described. While sequence-based tools to characterize the functional landscape in non-model species are maturing and becoming more readily available, easy-to-use network-based methods inferring plant gene functions are not as prevalent and have limited functionality.