Acta Physiologiae Plantarum最新文献

Salt stress significantly inhibits seed germination in tobacco, yet the molecular mechanisms underlying this process remain largely unexplored. In this study, we demonstrated that NtOGG1, encoding an 8-oxoguanine DNA glycosylase, functions as a positive regulator of salt tolerance during seed germination. Under 150 mM NaCl stress, the overexpressing NtOGG1 line (NtOGG1-OE) exhibited higher germination and seedling percentage compared to wildtype (WT), whereas CRISPR–Cas9 knockout mutant showed reductions in both parameters. RNA-Seq analysis revealed that differentially expressed genes (DEGs) in the NtOGG1-OE line, including ethylene-responsive transcription factors (ERFs), respiratory burst oxidase homologs (RBOHs), and catalase (CAT) genes, are implicated in the mitogen-activated protein kinase (MAPK) signaling pathway. Further qRT-PCR and physiological assays confirmed that the enhanced ethylene responses and reduced accumulation of reactive oxygen species (ROS) significantly promote seed germination in the NtOGG1-OE line under salt stress. These findings establish NtOGG1 as a key regulator influencing seed germination under salt stress, providing a promising molecular target for breeding salt-tolerant tobacco cultivars.

Research was done to observe the magnetic field effect on root characteristics in sunflower crop raised from seeds exposed to the 200 mT magnetic field for 2 h. Treated seeds were grown under three different irrigation treatments at research field of ICAR-IARI, New Delhi, India along with control. Outcomes of the study exhibited that in treatment, plants had enhanced total root length, root surface area, and root volume in various development stages of the crop. Crop yield per volume of water supplied (water productivity, WP) had significantly more value in treatments than the control. The difference was higher in crop having less irrigation as compared to more irrigation in treatment than the control. Treatment had improved seed yield by 3 to 9% than control. Hence, sunflower seeds treated by 200 mT magnetic field for 2 h before sowing enhanced root growth, resulting in better water productivity and seed yield.

Although the biogeography and systematics of Saxifragaceae taxa have advanced, the plastome structure, evolution, and phylogeny of Bergenia ciliata remain to be investigated. The plastid genome comprises 131 genes, which include 86 protein-coding genes, 37 transfer RNA genes, and 8 ribosomal RNA genes. Nucleotide diversity (Pi) analysis unveils significant variability in specific protein-coding genes, such as rps12_copy, matK, clpP, ndhF, and ccsA, that could be used as potential biomarkers. The IRb/SSC junction analysis reveals consistent transcription of ycf1 and ndhF across species. Exploration of Ka/Ks ratios in 89 protein-coding genes reveals that 73 genes are under purifying selection, while petL demonstrated positive selection. Codon usage bias analysis revealed variable ENC values (25.61–61), indicating preferences in codon usage, with neutrality plots indicating a GC-rich bias influenced by natural selection and mutation pressure. RSCU analysis demonstrates distinct preferences for certain codons, particularly A/T (U)-ending codons in B. ciliata. The phylogenetic analysis establishes a robust relationship, with B. ciliata and B. scopulosa forming a closely related cluster (BS=100) indicative of a shared recent common ancestor. This study provides a foundational genomic resource for exploring evolutionary dynamics and ecological interactions of B. ciliata within Saxifragaceae.

Euscaphis konishii and Euscaphis japonica are shrubs or small trees belonging to the Staphyleaceae family and are excellent ornamental fruit plants with high ornamental and medicinal value. There are a few studies on the cold tolerance of E. konishii and E. japonica, and their metabolic response to cold is not clear. Here, the non-targeted metabolomics (GC‒MS) technique was used to elucidate the response of E. konishii and E. japonica to cold at the metabolic level. Under cold treatment, E. konishii exhibited 10 upregulated and 1 downregulated differentially expressed metabolites (DEMs), whereas 10 upregulated and 7 downregulated DEMs were identified in E. japonica. The contents of key metabolites, such as sugars including raffinose and glucose-6-phosphate, amino acids including lysine and methionine 2, unsaturated fatty acids including linoleic acid, and flavonoid compounds including neohesperidin, were increased in E. konishii in response to cold. The contents of key metabolites, such as sugars including raffinose, trehalose, and fructose-6-phosphate, amino acids including aspartic acid 1 and aspartic acid 2, and organic acids including pyruvate and taurine, were increased, and sugars of sedoheptulose, organic acids of α-ketoglutaric acid, flavonoid compounds of hesperidin were decreased in E. japonica in response to cold. DEMs in E. konishii were significantly enriched in “linoleic acid metabolism,” while the DEMs in E. japonica were significantly enriched in “monobactam biosynthesis,” “cysteine and methionine metabolism,” “taurine and hypotaurine metabolism,” “sulfur metabolism,” and “ABC transporters.” This research expounds the metabolic differences of E. konishii and E. japonica in response to cold and provides a foundation for improving their resistance to cold stress.

Unfavorable temperatures during germination can significantly disrupt the physiological and biochemical processes crucial for seed germination, posing a challenge to soybean crop establishment and overall yield potential. Seed priming has emerged as a technique that has the potential to enhance crop establishment under high-temperature stress conditions. The presented study evaluated the impact of seed priming [without seed priming, hydropriming, and osmopriming with polyethylene glycol (PEG) 6000 @ −0.5, −1.0, −1.5 and −2.0 megapascal (MPa) for 6 h] at different temperatures (25, 30, 35, and 40℃) on physiological and biochemical parameters under controlled conditions. The experiment was conducted twice in factorial complete randomized design, each replicated four times. The results showed that seed priming with PEG @ −1.5 MPa recorded higher speed of germination, germination percentage, total seedling length, seedling dry weight, and vigor indices at 30 °C than other seed priming treatments and temperatures. Seed treated with PEG @ −1.5 MPa recorded higher speed of germination (15.3 and 8.2%), seedling vigor index I and II (19.6% and 13.0%, and 10.3% and 6.5%) over control and hydropriming, respectively. Compared to other priming treatments, PEG @ −1.5 MPa primed seeds exhibited significantly lower electrical conductivity, higher dehydrogenase activity, and higher percentage of stained seeds at the different temperatures tested (25, 30, 35, and 40℃). This implies that seed priming with PEG @ −1.5 MPa could serve as a valuable method to enhance the physiological and biochemical parameters of soybean at high temperatures, potentially fostering early plant development and augmenting yield potential.

The natural balance of biological systems, particularly plants, faces strains from various biotic and abiotic stressors. One such concern in agriculture is the accumulation of cobalt (Co) in soil, impacting plant growth and soil microflora adversely. This study delved into the impact of cobalt contamination on maize plants, vital for human and poultry consumption, and explored the potential benefits of soil amendments such as biochar (B) and arbuscular mycorrhizal fungi (AMF) as cost-effective remedies to enhance plant growth in metal-polluted soils. The investigation was conducted through a pot experiment to understand their effects. The experiment evaluated the impact of Rhizophaus intraradices and biochar on maize plants grown under different cobalt concentrations (0, 60, and 120 ppm). A wide range of physiological parameters, including plant height, number of leaves, root and shoot fresh and dry weight, relative water content, electrolyte leakage, chlorophyll and carotenoid content, oxidative stress, cobalt distribution, and nutrient content, were analyzed. The results revealed that cobalt contamination had a negative impact on plant growth, reducing chlorophyll and carotenoid content, increasing oxidative stress, and elevating cobalt accumulation in the shoot while also decreasing nutrient content. However, Rhizophagus intraradices inoculation and biochar application were shown to be effective in reducing cobalt uptake in aerial parts, improving nutrient content, and reducing oxidative stress. This study highlights the potential of AMF and biochar as cost-effective amendments for improving maize growth and mitigating cobalt toxicity in contaminated soils.

The elevated atmospheric CO₂ concentration is expected to increase plant growth and productivity and improve water use efficiency. Hence, elevated CO₂ is considered to mitigate to some extent the adverse effects of drought. We aimed to investigate physio-morphological and biochemical responses of 2-year-old Persian oak (Quercus brantii Lindl.) seedlings to the elevated CO₂ concentration and drought alone and when combined. Persian oak seedlings were grown in growth chambers at two CO₂ concentrations (ambient; 380 ppm and elevated; 700 ppm) and two water regimes (well-watered; 100% of field capacity and water stress; about 50% of this value) for one growing season (8 months). The results showed elevated CO₂ concentration significantly increased collar diameter, shoot height, leaf area, biomass production, root volume, photosynthetic traits, leaf pigments (chlorophyll and carotenoids) content, and relative leaf water content. While, it decreased total N content of leaves, proline content, electrolyte leakage, Malondialdehyde content, and antioxidant enzymes (catalase, peroxidase, and ascorbate peroxidase) activity in comparison to ambient CO₂ concentration. However, the root length was unaffected in response to elevated CO₂. In contrast, drought had an adverse effect on the studied traits except for root length. These effects were alleviated by the presence of CO₂, as apparent in physio-morphological and biochemical traits. Our findings suggest that in different proposed climate change scenarios, Persian oak trees may tolerate drought in the presence of elevated CO₂.

Salinity stress is posing serious threat to global food production and accountable for 20–50% of yield loss in various crops via hampering morphological, biochemical, and physiological processes of plants. To evaluate the impact of 0-, 50-, and 100-mM salinity levels, a pot experiment was conducted under ambient conditions on mung bean cultivars (HUM 1 and HUM 16). Reduction in plant height was observed by 15.1% and 34.8% for HUM 1 and 7.3% and 27.5% for HUM 16 under 50 and 100 mM, respectively. Higher generation of superoxide radical (51.3%) and hydrogen peroxide (29.1%) was observed for HUM 1 under 100 mM resulting into higher membrane damage (51.0%), assessed in the form of MDA content. To counter this oxidative stress, significant induction in non-enzymatic and enzymatic antioxidants like ascorbic acid (11.2% and 28.9%), superoxide dismutase (29.9% and 48.0%), and catalase (25.4% and 60.9%) was observed for HUM 1 and HUM 16 under 100 mM, respectively. On the other hand, significant accumulation of phenols and flavonoids was also noticed for HUM 16 under 50 and 100 mM. Reduction in yield was recorded more for HUM 1 (33.6% and 46.9%) as compared to HUM 16 (15.8% and 41.4%) under 50 and 100 mM, respectively. Results of the present study clearly demonstrated that 100-mM salinity stress was more severe as compared to 50 mM, and the magnitude of impact was observed higher for HUM 1 as compared to HUM 16.

In the study carried out as a two-year greenhouse experiment, the effects of salicylic acid (SA; 0.5, 1.0 and 2.5 mM), methyl jasmonate (MJ; 5, 10 and 15 mM) and sodium nitroprusside (SNP; 0.5, 1.0 and 1.5 mM) treatments at different concentrations against cold stress (4 °C, 16 h) in Victoria variety grapevine saplings were investigated, and the most effective concentration ranges were investigated. 1.0 mM SA was found to be the most effective treatment to promote cold stress resistance of grapevines by increasing superoxide dismutase (114.23 U mg⁻¹ protein), catalase (1.024 U mg⁻¹ protein) and ascorbate peroxidase (20.43 U mg⁻¹ protein) enzyme activities while decreasing electrolyte leakage (14.44%) and lipid peroxidation (6.07 nmol g⁻¹) levels. Moreover, 10 mM MJ and 1.0 mM SNP treatments also contributed to the improvement of the osmotic adjustment capacity of grapevines by increasing proline content (MJ, 0.185 μmol g⁻¹; SNP, 0.435 μmol g⁻¹) and relative water content (MJ, 90.06%; SNP, 89.78%), and decreasing electrolyte leakage (MJ, 14.71%; SNP, 16.06%) and lipid peroxidation (MJ, 4.10 nmol g⁻¹; SNP, 5.96 nmol g⁻¹). Additionally, principal component analysis, heatmap and comprehensive evaluation based on the analytic hierarchy process indicated that 1.0 mM SA, 10 mM MJ and 1.0 mM SNP treatments performed better than other treatments in terms of both increasing plant resistance and reducing the severity of damage. This study contains important information that can provide a reference for researchers to enhance the adaptation ability of grapevines to cold stress and can enhance the success of future studies.