Acta Physiologiae Plantarum最新文献

This study investigates the enzymatic characteristics and interactions of trypsin and α-amylase from Rhyzopertha dominica and respective inhibitors from infested wheat lines during storage. We hypothesize that chromosomal segmental substitution lines (CSSLs) of wheat with higher initial concentrations of α-amylase and trypsin inhibitors maintain greater resistance against Rhyzopertha dominica over the storage periods; a defense that can be further improved by the application of exogenous inhibitors. A significant decline in trypsin and α-amylase inhibitor content was observed across wheat lines during prolonged storage, with PN 399 showing the least reduction, indicating their resilience behaviour. Trypsin activity peaked at a pH of 10.4 and showed maximum substrate affinity at 2 mM BApNA. Effective inhibitors of trypsin activity included Aprotinin and Leupeptin, reducing activity by up to 50%. Activators such as MgCl₂, CuSO₄, and CaCl₂ enhanced trypsin activity, while EDTA exhibited minimal effects. The α-amylase from Rhyzopertha dominica displayed an optimal pH of 7.0 and a optimum temperature of 40 °C, with maximum activity observed at 2% starch. Partial purification revealed peak enzyme activity in protein fractions from 30 to 60% ammonium sulfate saturation. Effective inhibitors like citric and oxalic acids reduced α-amylase activity significantly, while metal ions such as CaCl₂, NaCl, and MgCl₂ enhanced activity. The findings provide insights into enzyme kinetics and inhibitors, contributing to pest management strategies and the biochemical understanding of Rhyzopertha dominica in stored wheat.

Effect of pre sowing treatment of maize (Zea mays variety: GSF.2) seeds with Oxygen plasma has been investigated for the promotion of growth and the early biochemical changes. Oxygen plasma was produced in a RF plasma machine for exposing the seeds. A dose response curve in terms of energy levels and time of exposure to Oxygen plasma showed an optimum impact on growth at 30 W after 240 s of exposure. The activity of α-amylase was enhanced by Oxygen plasma during germination and early seedling growth. The expression of α-amylase gene was also enhanced by many folds. This was accompanied by a rise in the level of H₂O₂. It is concluded that H₂O₂ acts as a signaling molecule in maize seeds for enhancement of the activity of α-amylase by Oxygen plasma.

Understanding plant responses to environmental constraints is key to explaining ecological patterns and forecasting vegetation shifts under climate change. Elevational gradients, with their varying temperature, moisture, and nutrient levels, offer valuable insights into these adaptive strategies. This study examines the adaptive strategies of three Festuca species collected from two distinct altitudinal zones (1000 m and 2500 m a.s.l.) in the western Himalaya, Pakistan. Compared to the higher elevation (2500 m), Festuca kashmiriana and F. levingei exhibit greater species abundance at 1000 m, indicating a preference for lower-elevation habitats. However, when assessed at 2500 m relative to their counterparts at 1000 m, both species showed significant reductions in plant height, root length, biomass, spikelet length, inflorescence length, and number of leaves. These morphological declines were accompanied by a decrease in ionic content and thinning of root epiblema, cortex, and aerenchyma tissues, suggesting stress-induced limitations on growth and resource transport at higher altitudes. Despite these constraints, both species exhibited increased metaxylem and phloem areas in roots and stems at 2500 m, potentially reflecting compensatory anatomical adjustments to maintain water and nutrient transport under reduced atmospheric pressure and cooler temperatures. In contrast, Festuca simlensis demonstrated enhanced performance at 2500 m relative to 1000 m, characterized by extensive sclerenchyma, enlarged metaxylem vessels, increased phloem area, sclerified vascular tissues, and a thickened epidermis. These traits are indicative of structural reinforcement and improved water-use efficiency, conferring ecological advantage in colder and drier high-altitude conditions. Collectively, the findings provide novel insights into the species-specific adaptations of Festuca to elevation-induced environmental stresses, highlighting the ecological significance of morphological and anatomical variations in distribution pattern and plant survival strategies across elevational gradients.

The present research was undertaken to evaluate the phytoremediation and tolerance potential of new beneficial endophytic fungi in canola (Brassica napus L.) plants grown in Pb-contaminated soils. The treatments, arranged in a factorial completely randomized design with three replicates, included a novel fungal isolate (Libertella sp. F6), a commercial fungal isolate (Trichoderma longibrachiatum), and non-inoculated control (NC). The effects of fungal inoculation and exogenous application of the polyamine spermidine (Spd) were assessed across a range of Pb concentrations. Inoculated plants showed a decreasing trend in Pb accumulation and translocation indices with increasing Pb levels, with root bioconcentration factor (BCF) values exceeding one in most treatments (ranging from 1.0 to 13.4), indicating enhanced phytoremediation potential, particularly in the Libertella-inoculated plants. Hydrogen peroxide content was reduced by up to 75% in inoculated plants. Antioxidant enzyme activities were generally lower in inoculated plants than in the non-inoculated control across different Spd levels. Proline content (PC) increased (by 76%) in inoculated plants, with a more pronounced increase in Libertella-inoculated treatments. The Spd also positively influenced both enzyme activities and PC. In conclusion, Libertella sp. shows promise as a beneficial endophytic root fungus for improving Pb phytoremediation and tolerance in canola, especially when supplemented with an optimal dose of Spd.

Phytochromes are involved in the expression of nutrient transporter genes and participate in signaling responses in plants under nutritional deficiency. This study investigated the reciprocal interaction between phytochrome B1 (phyB1) and N, P, and K deficiency responses, specifically focusing on shoot-root communication. For this purpose, we used grafting combinations of the control genotype (WT) with the tomato phyB1-deficient mutant (phyB1) under nutritional sufficiency and individual deficiencies of N, P, and K. In nutrient-sufficient conditions, shoot phyB1 stimulated N and P uptake in the roots and increased stomatal conductance, transpiration, and dry weight accumulation , whereas root phyB1 regulated the accumulation of chlorophyll in the shoot. With N deficiency, the WT/phyB1 combination attenuated the damage caused by N deficiency by increasing the dry weight of the entire plant. Under P deficiency, the absence of root phyB1 decreased N uptake and increased malondialdehyde (MDA) accumulation . However, the deficiency of phyB1 impaired the water-use efficiency of P-deficient plants. Under K deficiency, both shoot and root phyB1 modulated N and K uptake. Furthermore, shoot phyB1 influenced the oxidative status of leaf tissues, as indicated by variations in MDA content, and was associated with enhanced photosynthetic performance. These findings suggest that the phyB1-deficient mutant may have potential as a rootstock to attenuate damage caused by N deficiency in tomato. The results also demonstrate that phyB1 is involved in shoot-root communication for the control of nutritional, physiological, and growth responses in tomato, raising new roles of this photoreceptor and perspectives on the plant nutrition studies.

Vicia faba seedlings were used to investigate the efficiency of electro/magnetization at various field intensities in alleviating the harmful effects of saltwater at a microscopic level. The experiment was conducted with commercial devices used to treat saltwater with an electromagnetic field intensity below 0.01 T and magnetic fields at 1.2, 1.4 and 1.6 T. Assessments were performed using a Vicia-micronucleus test under non-treated saltwater (8 dS/m) and saltwater exposed to electro/magnetic fields at the specified intensities. Saltwater significantly increased Na⁺ and Cl⁻ absorption by approximately 5-fold and 6.4-fold, respectively, and induced genotoxicity as evidenced by nuclear vacuolization and chromosomal aberrations, including fragments, c-mitosis, stickiness, bridges and loss of chromosomes and/or chromatids. These effects were accompanied by a 55% decrease in mitotic index (MI) and a17-fold increase in the frequency of micronucleus (MCN), parallel to the reduced root length, fresh and dry biomass, and root water content. Exposing saltwater to electro/magnetic fields (< 0.01 T and 1.2–1.6 T) significantly mitigated these deleterious effects. Electro/magnetization selectively reduced Cl⁻ uptake while maintaining Na⁺ absorption, increased MI (to 11.89–14.19%) and reduced MCN frequency, with the most pronounced reductions (31–66%) observed at the lowest intensities (< 1.2 T). Consequently, morphological and physiological parameters were markedly improved. The results demonstrate that the electro/magnetization alleviates salt-induced genotoxicity by selectively modulating ion absorption and promoting cellular recovery. Lower intensities (< 1.2 T) provided greater genoprotective effects, indicating that applying low-intensity electro/magnetic field is a practical approach to enhance crop tolerance to salinity.

Priming is a water-based method that partially hydrates seeds to activate the early germination process. Faba bean (Vicia faba L.) seeds typically take 7–14 days to germinate under normal conditions. Delayed germination may reduce faba bean plant establishment and potential yield. A greenhouse pot experiment evaluated the effects of seed priming treatments on photosynthetic traits and root architecture of four faba bean varieties (Windsor, Purple Negreta, Big Organic, and Midnight). Seeds were primed with water (hydropriming), NaCl (osmopriming), bulk ZnO, and nano-ZnO. Results revealed significant variation among varieties and priming treatments for morphological, physiological, and root-related traits. Midnight demonstrated the lowest growth and delayed flowering. Windsor and Purple Negreta exhibited higher shoot biomass and branching. Nano-ZnO significantly enhanced plant height and shoot dry matter, whereas NaCl priming increased root biomass and branching. Gas exchange parameters, including net photosynthesis rate (Pn), transpiration rate (E), and water use efficiency (WUE), were positively influenced by seed priming across growth stages. Water priming notably enhanced Pn and WUE, particularly in the Windsor variety. Chlorophyll content (SPAD) increased under seed priming, especially at the flowering stage. Specific root length decreased under priming, with NaCl resulting in the lowest values. Application of nano-ZnO reduced the number of roots by 11% while increasing root depth by 8% compared to the control. Overall, seed priming may enhance growth, photosynthesis, and root development of faba beans under controlled conditions regardless of seed size.

The circadian clock is the internal time-keeping mechanism that anticipates changes in environmental signals in a 24-hour diurnal manner and prepares the plant for synchronization, survival and fitness. Recent research revealed that alterations in components of various hormone and stress-responsive pathways can influence the circadian clock functions and rhythm. Hence, the circadian clock trades off between the growth and defense responses by modulating the robustness or pace of the rhythm through direct or indirect interactions with components of various signaling pathways and networks. Disruptions of the intricate time-keeping processes caused by biotic or abiotic factors can significantly impact plant health. Therefore, it is vital to explore strategies for maintaining plant vitality in the face of such challenges and ensuring the continued functionality of the biological clock. This review discusses contemporary progress in understanding the influence of various unfavorable environmental conditions upon circadian clock function relayed onto the plant responses. It synthesizes current knowledge regarding the responses of clock components to different conditions while identifying areas that remain unexplored. Understanding such processes will allow us to expand the productivity of plants and help us to fortify them against several stressors, particularly in the context of sustainable agriculture and the climate crises.

This study investigated the influence of specific light-emitting diodes (LEDs) on lettuce seed germination, growth, and the accumulation of health-promoting compounds. The results revealed that LED lights significantly impacted both red (Jeok Chi Ma) and green (Cheong Chi Ma) lettuce cultivars and compared to natural light. Red (R)-blue (B) light combinations accelerated germination in the red cultivar, while R light alone had the opposite effect in the green cultivar. R light enhanced shoot fresh weight for both cultivars, with the combination of R-B light showing promising results as well. B light promoted root growth in both cultivars, followed by white light. R light maximized root length (RL), while blue and white light were most effective for root volume (RV). B light significantly increased the levels of health-promoting compounds like phenolics (PCs), anthocyanins (ANTs), and chlorophyll a (Chl a) and chlorophyll b (Chl b) in both cultivars. Red light, on the other hand, maximized carotenoids (CARs) content. Natural light resulted in the lowest levels of these compounds. Blue and R light respectively stimulated the expression of key genes in the ANTs and CARs biosynthetic pathways, with varying responses observed between the red and green cultivars. Overall, this study highlights the potential of utilizing specific LED light wavelengths to optimize lettuce growth and enhance the accumulation of health-promoting compounds. The findings suggest that tailoring light spectrums based on cultivar type can be a valuable strategy for controlled environment agriculture.

DEAD-box RNA Helicases (RHs) have been proved effective in plants against stress conditions, increasing their tolerance to different environmental stresses. To date, many different studies have revealed the occurrence of these proteins in many plants; however, studies of DEAD-box RHs in wheat, particularly those targetted to chloroplast, are still waiting to be studied. In this article, we performed an extensive genome-wide analysis of DEAD-box RHs in wheat genome. The results revealed that wheat genome consists of 116 RHs that have been retrieved using https://plants.ensembl.org/index.html. Among the 116 DEAD-box RHs, 50 were found to have the DEAD motif. While 39, out of 50 were found predicted to be localized to chloroplast by analyzing amino acid sequence of the DEAD-box RHs using a web-based prediction server (http://avermitilis.ls.kitasato-u.ac.jp/chlorop/). These 39 DEAD-box RHs were found to have sequences of chloroplast transit peptide (cTP). The predicted chloroplast localized DEAD-box RHs were analyzed for their distribution on chromosome and found unevenly distributed across the 21 chromosomes of common bread wheat. DEAD-box RHs with more than 40 cTP length were selected and proceeded for the analysis of expression patterns under drought, heat, and salt stress conditions. The results revealed that TraHEN2, TraRH47a, TraRH47c, TraISE2 (6A, 6B), TraRH58, TraRH22 (5A, 5B, 5D), and TraRH39 (3A) were highly induced in heat stress, while the expressions of TraRH47 (a, and b), TraSTRS2 (3A), TraRH22 (5B, 5D) and TraRH39 (3A) were increased many folds under salt stress. Under drought stress the transcript level of TraRH47 (A, B), TraSTRS2 (3A), TraRH58, TraRH22 (5A, 5B) and TraRH39 were highly induced. However, expressions of TraRH33 remained reduced in all stresses. This study concludes that high induction of the mentioned DEAD-box RHs under drought, salt and heat play important role in wheat responses to abiotic stress conditions. The study may lead the foundation that over-expression of these genes in wheat and other crops may develop stress-resistance, which may lead to high yield and possibly meet the demands of the increasing population.