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Treatment of plant seeds with electromagnetic fields or non-thermal plasmas aims to take advantage of plant functional plasticity towards stimulation of plant agricultural performance. In this study, the effects of pre-sowing seed treatment using 200 Pa vacuum (7 min), 5.28 MHz radio-frequency cold plasma (CP −2, 5, and 7 min) and electromagnetic field (EMF −5, 10, 15 min) on seed germination kinetics, content of phytohormones, morphometric parameters of seedlings and leaf proteome were assessed. CP 7 min and EMF 15 min treatments caused 19–24% faster germination in vitro ; germination in the substrate was accelerated by vacuum (9%) and EMF 15 min (17%). The stressors did not change the seed germination percentage, with exception of EMF 5 min treatment that caused a decrease by 7.5%. Meanwhile both CP 7 min and EMF 15 min treatments stimulated germination, but the EMF treatment resulted in higher weight of leaves. Stressor-specific changes in phytohormone balance were detected in seeds: vacuum treatment decreased zeatin amount by 39%; CP treatments substantially increased gibberellin content, but other effects strongly varied with the treatment duration; the abscisic acid content was reduced by 55–60% after the EMF treatment. Analysis of the proteome showed that short exposure of seeds to the EMF or CP induced a similar long-term effect on gene expression in leaves, mostly stimulating expression of proteins involved in photosynthetic processes and their regulation.

Dispersal is a key step in land plant life cycles, usually via formation of spores or seeds. Regulation of spore- or seed-germination allows control over the timing of transition from one generation to the next, enabling plant dispersal. A combination of environmental and genetic factors determines when seed germination occurs. Endogenous hormones mediate this decision in response to the environment. Less is known about how spore germination is controlled in earlier-evolving nonseed plants. Here, we present an in-depth analysis of the environmental and hormonal regulation of spore germination in the model bryophyte Physcomitrella patens (Aphanoregma patens). Our data suggest that the environmental signals regulating germination are conserved, but also that downstream hormone integration pathways mediating these responses in seeds were acquired after the evolution of the bryophyte lineage. Moreover, the role of abscisic acid and diterpenes (gibberellins) in germination assumed much greater importance as land plant evolution progressed. We conclude that the endogenous hormone signalling networks mediating germination in response to the environment may have evolved independently in spores and seeds. This paves the way for future research about how the mechanisms of plant dispersal on land evolved.

Heavy metal stress negatively affects the growth of medicinal plants. While the effects of Helium–Neon (He–Ne) laser on seed germination and stress tolerance in plants has garnered significant attention, little is known concerning the impacts of He–Ne laser irradiation on heavy metal tolerance in plants. Therefore, the current study was conducted to appraise the effect of different durations (0, 20, and 40 min) of seed priming with He–Ne laser (10 mW mm −2 ) on the antioxidant system of Silybum marianum L. plants under various Pb concentrations (0, 250, and 500 ppm). Lead phytotoxicity was evident by significant reductions in fresh and dry weights of shoots and roots, total chlorophyll (TChl) content and relative water content (RWC), as well as increases in H 2 O 2 and malondialdehyde contents in roots and leaves. Seed irradiation with He–Ne laser for 20 min significantly improved these parameters, enhancing Pb tolerance. Conversely, the prolonged laser priming (40 min) resulted in less favorable outcomes, including reduced growth, TChl content, and RWC, while also exacerbating oxidative damage to membranes even under non-stressful conditions. The 20-min laser priming systemically mitigated Pb-induced lipid peroxidation and H 2 O 2 accumulation by boosting the activities of superoxide dismutase and catalase and increasing proline content in leaves and roots of milk thistle plants. These findings and multivariate analysis suggest that optimal dose of laser initiates a “stress memory” in seeds which is activated upon subsequent exposure to Pb stress, boosting the plant defensive mechanisms and enabling the plant to better cope with oxidative damage. This study underscore the promising potential of He–Ne laser priming as a novel strategy for increasing heavy metal tolerance in medicinal plants like milk thistle, offering an eco-friendly technique for maintaining their productivity under heavy metal stress.

Protection of seeds from ionizing radiation is an important future need in space travel. We examined the usefulness of eumelanin from the fungus Gliocephalotrichum MTCC 5489 for this purpose. Seeds of Oryza sativa , Brassica nigra , Vigna radiata and V. aconitifolia were enclosed in Petri dishes coated with paint containing various concentrations of nanomelanin and exposed to doses of 0.1 to 2.0 kGy Cs-137 or 0.1 to 0.5 kGy Co-60 radiation. While Cs-137 radiation severely affected the rate of germination (germination index, GI) and germination percentage of Oryza sativa , whereas other seeds were less affected, Co-60 markedly diminished the GI of all the seeds. Increasing concentrations of melanin coating afforded significant protection to the GI of O. sativa seeds exposed to Cs-137 and to all seeds exposed to Co-60 radiation. The germination percentage of seeds was dose- and radiation dependent, with no effect observed for all doses of Cs-137 or 0.1 kGy Co-60 radiation, whereas 0.5 kGy Co-60 radiation killed 50 to 60% of the unprotected seeds. Melanin paint offered nearly 100% survival. This study demonstrated that melanin-containing materials can provide effective shielding from gamma radiation for diverse types of seeds that are important for human consumption, which has implications for space agriculture and agriculture in extreme environments.

Rice (Oryza sativa L.) grain is a major dietary source of cadmium (Cd), which is toxic to humans, but no practical technique exists to substantially reduce Cd contamination. Carbon ion-beam irradiation produced three rice mutants with <0.05 mg Cd⋅kg ⁻¹ in the grain compared with a mean of 1.73 mg Cd⋅kg ⁻¹ in the parent, Koshihikari. We identified the gene responsible for reduced Cd uptake and developed a strategy for marker-assisted selection of low-Cd cultivars. Sequence analysis revealed that these mutants have different mutations of the same gene (OsNRAMP5), which encodes a natural resistance-associated macrophage protein. Functional analysis revealed that the defective transporter protein encoded by the mutant osnramp5 greatly decreases Cd uptake by roots, resulting in decreased Cd in the straw and grain. In addition, we developed DNA markers to facilitate marker-assisted selection of cultivars carrying osnramp5 . When grown in Cd-contaminated paddy fields, the mutants have nearly undetectable Cd in their grains and exhibit no agriculturally or economically adverse traits. Because mutants produced by ion-beam radiation are not transgenic plants, they are likely to be accepted by consumers and thus represent a practical choice for rice production worldwide.

Key messageCross-talk between light and ABA signaling is mediated by physical interaction between HY5 and ABI5 Arabidopsis.Plants undergo numerous transitions during their life-cycle and have developed a very complex network of signaling to integrate information from their surroundings to effectively survive in the ever-changing environment. Light signaling is one of the crucial factors that govern the plant growth and development from the very first step of that is from seedling germination to the flowering. Similarly, Abscisic acid (ABA) signaling transduces the signals from external unfavorable condition to the internal developmental pathways and is crucial for regulation of seed maturation, dormancy germination and early seedling development. These two fundamental factors coordinately regulate plant wellbeing, but the underlying molecular mechanisms that drive this regulation are poorly understood. Here, we identified that two bZIP transcription factors, ELONGATED HYPOCOTYLE 5 (HY5), a positive regulator of light signaling and ABA-INSENSITIVE 5 (ABI5), a positive regulator of ABA signaling interacts and integrates the two pathways together. Our phenotypic data suggest that ABI5 may act as a negative regulator during photomorphogenesis in contrast, HY5 acts as a positive regulator of ABA signaling in an ABA dependent manner. We further showed that over-expression of HY5 leads to ABA-hypersensitive phenotype and late flowering phenotype. Taken together, our data provides key insights regarding the mechanism of interaction between ABI5-HY5 that fine tunes the stress and developmental response in Arabidopsis.

The benefit of not containing the gluten complex protein also provides problems with the achievement of typical and proper texture, especially in bakery products. Ultrasound (US) treatment has been previously studied on buckwheat as assistance treatment facilitating the release of antioxidant compounds. However, there is no study regarding the changes occurring in US-treated buckwheat grains regarding the structure-creating capacity, like water absorption, gelling, and pasting. The aim of this study is to the impact of US-treatment of buckwheat grains at 1:10, 1:5, and 1:2.5 solid:liquid ratio (in water). The particle size distribution, water absorption index (WAI), water solubility index (WSI), swelling power (SP), pasting characteristics, color, soluble, insoluble and total polyphenols content (SPC, IPC, TPC) and antioxidant activity (DPPH) were assessed in resulting flours. US-treatment caused specific agglomeration, resulting in bigger particles for 1:5, and 1:2.5 ratio treated samples, while higher dilution (1:10) increased smaller particle size fractions. The WAI and SP were the highest for the1:5 solid:liquid ratio sample, and the same sample revealed the highest peak viscosity, breakdown, and setback values. The ultrasound treatment increased the WSI, which was positively correlated with insoluble polyphenols content. The soluble polyphenols content decreased, and insoluble polyphenols content increased in all ultrasound treated samples. The DPPH scavenging activity remaining in grain after US treatment was lowered compared to the control sample. The relocation of pigments resulted in a redness and yellowish increase in all treated samples, while lightness was also increased but was most pronounced for a 1:10 ratio treated sample. The results suggest that ultrasound treatment of grain can improve the essential functional properties of buckwheat flour.

Seed germination is regulated by several environmental factors, such as moisture, oxygen, temperature, light, and nutrients. Light is a critical regulator of seed germination in small-seeded plants, including Arabidopsis and lettuce. Phytochromes, a class of photoreceptors, play a major role in perceiving light to induce seed germination. Classical physiological studies have long suggested the involvement of gibberellin (GA) and abscisic acid (ABA) in the phytochrome-mediated germination response. Recent studies have demonstrated that phytochromes modulate endogenous levels of GA and ABA, as well as GA responsiveness. Several key components that link the perception of light and the modulation of hormone levels and responsiveness have been identified. Complex regulatory loops between light, GA and ABA signaling pathways have been uncovered.

Lily seeds are commonly used for commercial production and genetic breeding, and their germination rates under different light conditions can be improved by chemical treatments. However, there is a lack of research to systematically screen the pre-treatment methods that are most suitable for various lily species. The study selected six lily species ( Lilium pumilum DC., Lilium davidii var. unicolor , Lilium auratum var. platyphyllum , Lilium lancifolium Thunb., Lilium distichum Nakai, and Lilium pensylvanicum Ker Gawl.) and employed a randomized complete block three-factor factorial design, with three factors being species, chemical treatments (0.1% KNO₃, 0.1% K 3 PO 4 , and different concentrations of GA 3 ), and light duration (0 h/d, 12 h/d, and 24 h/d). Each treatment included three replicates. Before sowing, the seeds were disinfected with 2% sodium hypochlorite solution for 15 min and rinsed with distilled water, then soaked in the corresponding solution for 1 h. Treated seeds were placed in petri dishes and incubated in an artificial climate chamber at 25 °C, with moist filter paper maintained and light conditions set accordingly. Germination was monitored continuously for 40 days, and the germination start time, completion time, and germination rate were recorded. Germination was defined as radicle emergence through the seed coat by 1–2 mm. The results showed that different lily species responded significantly differently to chemical treatment and light conditions. GA 3 treatment generally improved germination performance, and some species also showed a promoting effect under KNO 3 or K 3 PO 4 treatment. Comprehensive analysis revealed that L. lancifolium performed consistently well under multiple treatment conditions and can be selected as the preferred species for stimulation treatment.

Native to Iran, seedless barberry ( Berberis vulgaris L.) is a nutritionally and economically important crop prized for its therapeutic uses and food industry applications. Nevertheless, the vegetative propagation of the plant and lack of seeds limit conventional breeding techniques, therefore reducing genetic variation and impeding cultivars improvement. This work sought to maximize gamma radiation dosages to cause mutations in seedless barberry hence increasing genetic variability for breeding projects. Hardwood cuttings were subjected to gamma radiation dosages of 0 (control), 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 Gy using a Cobalt-60 source. Under both in vitro and in vivo settings, the impacts on survival rates, leaf and shoot development, and morphometric features were assessed. Results revealed that rising radiation doses significantly reduced survival rates and growth metrics. The LD 50 (Lethal dose) was determined to be roughly 19 Gy for the in vivo and 13.6 Gy for the in vitro. Gamma irradiation negatively influenced plant growth according to values for leaf length, leaf width, fresh weight, and dry weight growth reduction (GR 50 ). Optimal dosages for causing mutations, while preserving survival, were found to be 15 Gy for the in vivo and 10 Gy for the in vitro.