Acta Physiologiae Plantarum最新文献

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.

Aspalathus linearis (Burm.f.) R.Dahlgren, or rooibos, is an important commercial crop in the Western Cape, South Africa. The growth rate of rooibos is highest during the hot, dry summers typical for this region. This suggests that the plants have a wide range of adaptive responses including morphological, physiological, molecular, and biochemical mechanisms that help them cope with drought and heat stress. This study investigates differential expression of proteins in leaf samples harvested in summer from rooibos plants at two relatively cool, and two relatively hot sites in the Cederberg region. A total of 180 proteins were differentially expressed and of these, 113 proteins were more abundant at cooler sites while 67 proteins were more abundant at the heat-stressed (HS) sites. The higher temperatures at the HS sites led to a reduced protein abundance due to temperature thresholds for protein production during HS. Heat shock proteins were more abundant in the HS plants indicating an enhanced thermotolerance. Plants at the cooler sites overexpressed proteins associated with aiding photosynthesis and protecting photosystems, resulting in better photosynthetic rates and biomass accumulation. High light and moderate HS conditions prompted the regulation of proteins involved in chlorophyll synthesis and light protection to maintain effective functioning. Proteins involved in oxidative stress responses were expressed in plants at all sites, which was mirrored by high concentrations of antioxidants. Rooibos thermotolerance relies on the expression of HSPs and oxidative stress response proteins, while photosynthesis-related proteins dominate the cooler sites, optimizing their function and ultimately growth.

Key message

The incorporation of optimal concentration of polyethylene glycol with the optimized growth regulators in the nutrient medium promoted shoot growth and improved foliar micro-morpho-anatomical traits of Hedyotis biflora which improved the survival success of the plantlets during ex vitro hardening and field trials.

Polyethylene glycol (PEG) is widely recognized as an effective agent for stimulating osmotic stress in plant tissue cultures. In this study, the micropropagated shoots of Hedyotis biflora (L.) Lam was subjected to varied concentrations of polyethylene glycol (PEG-6000) under in vitro conditions to evaluate the effect of PEG on the morpho-anatomical development of shoots. The cultures were established by culturing nodal shoots on Murashige and Skoog (MS) medium supplemented with 2.0 mg L⁻¹ 6-benzylaminopurine (BAP), and the shoots were proliferated on the optimized plant growth regulators (1.0 mg L⁻¹ BAP + 0.5 mg L⁻¹ Kinetin (Kn) + 0.1 mg L⁻¹ Indole-3-acetic acid (IAA). Among the varied concentrations of PEG used in the MS medium, 60 mg L⁻¹ PEG with optimized growth regulators in the medium increased the rate of proliferation and elongation of shoots (14.0 shoots with 7.0 cm length) and leaf area (1.6 cm length × 1.0 cm width) than the control (medium without PEG). The foliar micro-morpho-anatomical elucidations revealed that the control leaves showed a thin cuticle, non-functional stomata, mesophyll with isobilateral tissues, and poorly developed mechanical, dermal, and vascular tissues. The incorporation of 60 mg L⁻¹ PEG (optimal) in the medium increased cuticle thickness, palisade and spongy mesophyll differentiation, functional stomata, dense vascular tissues, and well-developed ground tissues. The PEG-treated shoots showed better rhizogenesis on half-strength MS medium containing 2.0 mg L⁻¹ Indole-3-butyric acid (IBA) (21.0 roots with 4.0 cm average length). These morphometric and structural improvements were sequentially reflected in the increased survival of plantlets (96%) during acclimatization and field transplantation of H. biflora.

Fonio millet is an orphan crop with great potential for economic and food security. However, drought negatively affects its production and yield in semi-arid and arid regions. This study compared the growth and metabolomic profiles of two contrasting fonio cultivars (NGB02089 and NGB02082) in response to water stress at the seedling stage. The results showed variation in the morph-agronomic characters of the cultivars. There were also significant (p < 0.05) positive correlations in the traits studied, which means that the traits can be improved simultaneously. Chlorophyll content increased progressively with weeks after sowing (WAS) but decreased when seedlings were exposed to water stress. The biomass yield of NGB02082 was higher than that of NGB02089, although the latter grew more vigorously. However, NGB02089 had longer roots. The GC–MS analysis identified 12 significant metabolites that differed in composition between the fonio cultivars, including sugars, fatty acids and siloxanes. The amount of siloxane decreased in NGB02082 with increasing drought duration, but increased in NGB02089. Similarly, cis-13-octadecenoic acid was present in NGB02082 at 4 WAS but absent at 5 WAS, while NGB02089 produced more metabolites. Similarly, phthalimide, triacontane, vaccenic acids, and cholestane were produced in response to drought stress duration. The results of this study showed that NGB02089 and NGB02082 have different metabolomic responses to drought, conferring resistance to NGB02089 while NGB0282 is susceptible to drought. The result of this study suggests that metabolic responses to drought may be useful in developing varieties with better tolerance or adaptation to drought conditions.