Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.905
Filtrar
1.
Front Plant Sci ; 15: 1417632, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38966139

RESUMEN

Introduction: Abscisic acid (ABA) can negatively regulate seed germination, but the mechanisms of ABA-mediated metabolism modulation are not well understood. Moreover, it remains unclear whether metabolic pathways vary with the different tissue parts of the embryo, such as the radicle, hypocotyl and cotyledon. Methods: In this report, we performed the first comprehensive metabolome analysis of the radicle and hypocotyl + cotyledon in Pinus koraiensis seeds in response to ABA treatment during germination. Results and discussion: Metabolome profiling showed that following ABA treatment, 67 significantly differentially accumulated metabolites in the embryo were closely associated with pyrimidine metabolism, phenylalanine metabolism, cysteine and methionine metabolism, galactose metabolism, terpenoid backbone biosynthesis, and glutathione metabolism. Meanwhile, 62 metabolites in the hypocotyl + cotyledon were primarily involved in glycerophospholipid metabolism and glycolysis/gluconeogenesis. We can conclude that ABA may inhibit Korean pine seed germination primarily by disrupting the biosynthesis of certain plant hormones mediated by cysteine and methionine metabolism and terpenoid backbone biosynthesis, as well as reducing the reactive oxygen species scavenging ability regulated by glutathione metabolism and shikimate pathway in radicle. ABA may strongly disrupt the structure and function of cellular membranes due to alterations in glycerophospholipid metabolism, and weaken glycolysis/gluconeogenesis in the hypocotyl + cotyledon, both of which are major contributors to ABA-mediated inhibition of seed germination. These results highlight that the spatial modulation of metabolic pathways in Pinus koraiensis seeds underlies the germination response to ABA.

2.
Proc Natl Acad Sci U S A ; 121(28): e2404887121, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38968100

RESUMEN

The timing of seed germination is controlled by the combination of internal dormancy and external factors. Temperature is a major environmental factor for seed germination. The permissive temperature range for germination is narrow in dormant seeds and expands during after-ripening (AR) (dormancy release). Quantitative trait loci analyses of preharvest sprouting in cereals have revealed that MKK3, a mitogen-activated protein kinase (MAPK) cascade protein, is a negative regulator of grain dormancy. Here, we show that the MAPKKK19/20-MKK3-MPK1/2/7/14 cascade modulates the germination temperature range in Arabidopsis seeds by elevating the germinability of the seeds at sub- and supraoptimal temperatures. The expression of MAPKKK19 and MAPKKK20 is induced around optimal temperature for germination in after-ripened seeds but repressed in dormant seeds. MPK7 activation depends on the expression levels of MAPKKK19/20, with expression occurring under conditions permissive for germination. Abscisic acid (ABA) and gibberellin (GA) are two major phytohormones which are involved in germination control. Activation of the MKK3 cascade represses ABA biosynthesis enzyme gene expression and induces expression of ABA catabolic enzyme and GA biosynthesis enzyme genes, resulting in expansion of the germinable temperature range. Our data demonstrate that the MKK3 cascade integrates temperature and AR signals to phytohormone metabolism and seed germination.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Regulación de la Expresión Génica de las Plantas , Germinación , Semillas , Temperatura , Germinación/fisiología , Germinación/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Semillas/crecimiento & desarrollo , Semillas/metabolismo , Semillas/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , MAP Quinasa Quinasa 3/metabolismo , MAP Quinasa Quinasa 3/genética , Sistema de Señalización de MAP Quinasas/fisiología , Latencia en las Plantas/genética , Latencia en las Plantas/fisiología , Transducción de Señal , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas Quinasas Activadas por Mitógenos/genética
3.
J Plant Physiol ; 301: 154301, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38968782

RESUMEN

Abscisic acid (ABA) and gibberellin (GA) are major regulators of seed dormancy, an adaptive trait closely associated with preharvest sprouting. This study examined transcriptional regulation of ABA and GA metabolism genes and modulation of ABA and GA levels in seeds of barley genotypes exhibiting a range of dormancy phenotype. We observed a very strong negative correlation between genetic variation in seed germination and embryonic ABA level (r = 0.85), which is regulated by transcriptional modulation of HvNCED1 and/or HvCYP707A genes. A strong positive correlation was evident between variation in seed germination and GA level (r = 0.64), mediated via transcriptional regulation of GA biosynthesis genes, HvGA20ox2 and/or HvGA3oxs, and GA catabolism genes, HvGA2ox3 and/or HvGA3ox6. Modulation of the ABA and GA levels in the genotypes led to the prevalence of ABA to GA level ratio that exhibited a very strong negative correlation (r = 0.84) with seed germination, highlighting the importance of a shift in ABA/GA ratio in determining genetic variation of dormancy in barley seeds. Our results overall show that transcriptional regulation of specific ABA and GA metabolism genes underlies genetic variation in ABA/GA ratio and seed dormancy, reflecting the potential use of these genes as molecular tools for enhancing preharvest sprouting resistance in barley.

4.
Ecol Evol ; 14(7): e11650, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38962027

RESUMEN

Agricultural grasslands play an important role in conserving the biodiversity of the European cultural landscape. Both, litter cover and soil nutrient availability, change with grassland management, but it is not well-studied how seedling recruitment and growth of multiple grassland species are influenced by their single or combined effects. Therefore, we studied the effects of nitrogen fertilization (100 kg N per year and ha) and litter cover (250 gdw per m2) on seedling recruitment and growth of 75 temperate grassland species (16 graminoid species, 51 forb species, 8 legume species) in a full factorial microcosm experiment. Overall, fertilizer reduced seedling emergence, while litter cover increased it even when combined with fertilization. Fertilization increased seedling height and biomass, and the combination of fertilizer and litter resulted in even stronger responses. Litter cover alone did not influence seedling biomass or seedling height. While the overall direction of treatment effects was similar across functional groups, their strengths were mostly weaker in graminoids than in non-legume forbs and legumes. Positive litter effects on seedling emergence were stronger in large-seeded species. Positive fertilization effects on seedling growth were stronger in small-seeded species, while their seedling biomass was negatively affected by litter cover. In summary, our results show for multiple grassland species that the combination of litter cover and fertilization modulates their single effects. The varying sensitivity of how grassland species representing different functional groups and seed sizes respond with their seedling emergence and growth to litter cover and nitrogen fertilization indicates that the consequences of land-use change on grassland diversity and composition already start to manifest in the earliest stages of the plant life cycle.

5.
Plant J ; 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38963754

RESUMEN

DNA glycosylases initiate the base excision repair (BER) pathway by catalyzing the removal of damaged or mismatched bases from DNA. The Arabidopsis DNA glycosylase methyl-CpG-binding domain protein 4 like (MBD4L) is a nuclear enzyme triggering BER in response to the genotoxic agents 5-fluorouracil and 5-bromouracil. To date, the involvement of MBD4L in plant physiological processes has not been analyzed. To address this, we studied the enzyme functions in seeds. We found that imbibition induced the MBD4L gene expression by generating two alternative transcripts, MBD4L.3 and MBD4L.4. Gene activation was stronger in aged than in non-aged seeds. Seeds from mbd4l-1 mutants displayed germination failures when maintained under control or ageing conditions, while 35S:MBD4L.3/mbd4l-1 and 35S:MBD4L.4/mbd4l-1 seeds reversed these phenotypes. Seed nuclear DNA repair, assessed by comet assays, was exacerbated in an MBD4L-dependent manner at 24 h post-imbibition. Under this condition, the BER genes ARP, APE1L, and LIG1 showed higher expression in 35S:MBD4L.3/mbd4l-1 and 35S:MBD4L.4/mbd4l-1 than in mbd4l-1 seeds, suggesting that these components could coordinate with MBD4L to repair damaged DNA bases in seeds. Interestingly, the ATM, ATR, BRCA1, RAD51, and WEE1 genes associated with the DNA damage response (DDR) pathway were activated in mbd4l-1, but not in 35S:MBD4L.3/mbd4l-1 or 35S:MBD4L.4/mbd4l-1 seeds. These results indicate that MBD4L is a key enzyme of a BER cascade that operates during seed imbibition, whose deficiency would cause genomic damage detected by DDR, generating a delay or reduction in germination.

6.
Artículo en Inglés | MEDLINE | ID: mdl-38965111

RESUMEN

Cadmium (Cd) poses serious threats to plant growth and development, whereas the use of plant growth-promoting rhizobacteria (PGPR) has emerged a promising approach to diminish Cd retention in crops. A pot experiment was conducted to evaluate the effect of Cd tolerant strain Acinetobacter sp. SG-5 on growth, phytohormonal response, and Cd uptake of two maize cultivars (3062 and 31P41) under various Cd stress levels (0, 5, 12, 18, 26, and 30 µM CdCl2). The results revealed that CdCl2 treatment significantly suppressed the seed germination and growth together with higher Cd retention in maize cultivars in a dose-dependent and cultivar-specific manner with pronounced negative effect in 31P41. However, SG-5 strain exerted positive impact by up-regulating seed germination traits, plant biomass, photosynthetic pigments, enzymatic and non-enzymatic antioxidants, endogenous hormone level indole-3-acetic acid (IAA), abscisic acid (ABA), and sustained optimal nutrient's levels in both cultivars but predominantly in Cd-sensitive one (31P41). Further, Cd-resistant PGPR decreased the formation of reactive oxygen species in terms of malondialdehyde (MDA) and hydrogen peroxide (H2O2) verified through 3, 3'-diaminobenzidine (DAB) and nitroblue tetrazolium (NBT) analysis in conjunction with reduced Cd uptake and translocation in maize root and shoots in comparison to controls, advocating its sufficiency for bacterial-assisted Cd bioremediation. In conclusion, both SG-5 inoculated cultivars exhibited maximum Cd tolerance but substantial Cd tolerance was acquired by Cd susceptible cultivar-31P41 than Cd-tolerant one (3062). Current work recommended SG-5 strain as a promising candidate for plant growth promotion and bacterial-assisted phytomanagement of metal-polluted agricultural soils.

7.
Ecol Evol ; 14(7): e11671, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38952654

RESUMEN

Despite their crucial role in determining the fate of seeds, the type and breaking mode of seed dormancy in peatland plants in temperate Asia with a continental monsoon climate are rarely known. Fifteen common peatland plant species were used to test their seed germination response to various dormancy-breaking treatments, including dry storage (D), gibberellin acid soaking (GA), cold stratification (CS), warm followed cold stratification (WCS), GA soaking + cold stratification (GA + CS) and GA soaking + warm followed cold stratification (GA + WCS). Germination experiment, viability and imbibition test, and morphological observation of embryos were conducted. Of the 15 species, nine showed physiological dormancy (PD), with non-deep PD being the dominant type. Four species, Angelica pubescens, Cicuta virosa, Iris laevigata, and Iris setosa exhibited morphophysiological dormancy. Two species, Lycopus uniflorus and Spiraea salicifolia, demonstrated nondormancy. Overall, the effect hierarchy of dormancy-breaking is: CS > GA > WCS > GA + CS > D > GA + WCS. Principal component analysis demonstrated that seed traits, including embryo length: seed length ratio, seed size, and monocot/eudicot divergence, are more likely to influence seed dormancy than environmental factors. Our study suggests that nearly 90% of the tested peatland plant species in the Changbai Mountains demonstrated seed dormancy, and seed traits (e.g. embryo-to-seed ratio and seed size) and abiotic environmental factors (e.g. pH and temperature seasonality) are related to germination behavior, suggesting seed dormancy being a common adaptation strategy for the peatland plants in the temperate montane environment.

8.
Artículo en Inglés | MEDLINE | ID: mdl-38958855

RESUMEN

Nanoparticles, owing to their unique physicochemical properties, have garnered significant attention in various scientific disciplines, including materials science, chemistry, biology, and environmental engineering. In recent years, the synthesis of metal oxide nanoparticles, such as NiO, Fe2O3, ZnO, SnO2, and CuO via green routes, has gained attraction due to their diverse applications in fields ranging from catalysis and electronics to medicine and environmental remediation. This study focuses on the green synthesis of copper oxide (CuO) and zinc oxide (ZnO) nanoparticles using Calotropis gigantea (Apple of Sodom) leaf extract as a reducing agent and stabilizer, with zinc nitrate (ZnNO3.6H2O) and copper nitrate (CuNO3.3H2O) as precursors. The hexagonal phase of ZnO and monoclinic plan structure of CuO with high crystallinity was confirmed by XRD and elemental composition by EDX analysis. With the help of an SEM image, particle size measured for CuO and ZnO using ImageJ software was found to be 56.08 nm and 46.49 nm, respectively. This study investigates the efficacy of nanoparticles in wastewater treatment, particularly focusing on methylene blue dye decolorization using the statistical processing of response surface methodology (RSM) using the Box-Behnken method. Additionally, it explores the impact of synthesized nanoparticles on seed growth enhancement, using Vigna radiata (green gram) seeds immersed in various doses of nanoparticles (0, 0.5, 1, 1.5, 2 mg/30 mL). Furthermore, the antibacterial activity of the nanoparticles against both gram-positive and gram-negative bacteria is evaluated. The results confirm the effectiveness of the materials for methylene blue dye removal, achieving 80.53% with CuO and 78.25% with ZnO. Significant seed growth was observed with a low nanoparticle dosage of 1.5 mg/30 mL, resulting in the highest seedling vigour index and germination percentage. This reduces the need for fertilizers and lessens environmental impact.

9.
Methods Mol Biol ; 2830: 51-62, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38977567

RESUMEN

Seed germination of a parasitic plant Striga hermonthica is elicited by strigolactones which are exuded from roots of host plants. Here, we describe a high-throughput germination assay and a method for visualizing in vivo strigolactone receptor functions with a fluorogenic probe.


Asunto(s)
Germinación , Lactonas , Semillas , Striga , Striga/fisiología , Striga/crecimiento & desarrollo , Striga/efectos de los fármacos , Semillas/crecimiento & desarrollo , Lactonas/metabolismo , Lactonas/farmacología , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/parasitología , Sondas Moleculares/química , Colorantes Fluorescentes/química
10.
Methods Mol Biol ; 2830: 27-34, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38977565

RESUMEN

Germination test is fundamental and commonly used technique for seed dormancy and germination studies, and proper assessment of dormancy level and germination ability of a given set of seeds is prerequisite for most of the studies. However, germination is very sensitive to imbibition conditions, and dormancy development is also sensitive to growth conditions of the mother plants. In this chapter, we describe tips for plant growth and germination test mainly for physiological and molecular genetic studies with Arabidopsis. This protocol can be applied for other plant species with relatively small seeds and for various studies to analyze the effect of light, phytohormones, and other chemicals in seed germination.


Asunto(s)
Arabidopsis , Germinación , Latencia en las Plantas , Reguladores del Crecimiento de las Plantas , Semillas , Latencia en las Plantas/genética , Semillas/crecimiento & desarrollo , Semillas/genética , Semillas/fisiología , Arabidopsis/genética , Arabidopsis/fisiología , Arabidopsis/crecimiento & desarrollo , Reguladores del Crecimiento de las Plantas/metabolismo , Luz
11.
Methods Mol Biol ; 2830: 131-136, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38977574

RESUMEN

Seed dormancy genes typically suppress germination and cell division. Therefore, overexpressing these genes can negatively affect tissue culture, interfering with the generation of transgenic plants and thus hampering the analysis of gene function. Transient expression in target cells is a useful approach for studying the function of seed dormancy genes. Here, we describe a protocol for transiently expressing genes related to seed dormancy in the scutellum of immature wheat (Triticum aestivum) embryos to analyze their effects on germination.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Germinación , Latencia en las Plantas , Semillas , Triticum , Triticum/genética , Triticum/crecimiento & desarrollo , Latencia en las Plantas/genética , Semillas/genética , Semillas/crecimiento & desarrollo , Germinación/genética , Biolística/métodos , Plantas Modificadas Genéticamente/genética , Genes de Plantas , Expresión Génica/genética
12.
Methods Mol Biol ; 2830: 63-69, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38977568

RESUMEN

The longevity of seeds, also known as storability, is the period of time for which a seed lot maintains its viability during storage. The method aims to determine longevity of a seed lot during storage in a controlled environment. Seeds are first rehydrated to a preset water content (or relative humidity, RH) and then incubated under controlled conditions for various periods of time to allow for deterioration to occur. At increasing intervals during storage, seeds are retrieved and viability is tested by scoring germination of the seed lot (i.e., radicle protrusion). From these data, a survival curve can be drawn depicting loss of germination during time of storage from which different parameters estimating longevity can be inferred. These parameters can be used to compare longevity between different seed lots, genotypes, or species at similar storage conditions. This test can also be used as a proxy to measure seed vigor or physiological seed quality.


Asunto(s)
Germinación , Semillas , Semillas/crecimiento & desarrollo , Semillas/fisiología , Humedad , Longevidad , Agua
13.
Methods Mol Biol ; 2830: 175-193, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38977578

RESUMEN

Different methodologies have been applied for the selection of preharvest sprouting resistance in cereal breeding programs. We describe here a series of methods used in practical wheat breeding programs in Japan, including phenotyping based on germination score after artificial rain treatments and genotyping using DNA markers. These methods can be modified and applied to breeding programs in which preharvest sprouting is a problem during cereal cultivation.


Asunto(s)
Germinación , Fenotipo , Fitomejoramiento , Triticum , Marcadores Genéticos , Genotipo , Germinación/genética , Japón , Fitomejoramiento/métodos , Triticum/genética , Triticum/crecimiento & desarrollo
14.
Int J Food Microbiol ; 422: 110812, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38970996

RESUMEN

Mild spore inactivation can be challenging in industry because of the remarkable resistance of bacterial spores. High pressure (HP) can trigger spore germination, which reduces the spore's resistance, and thereby allows mild spore inactivation. However, spore germination is heterogenous. Some slowly germinating or non-germinating spores called superdormant spores remain resistant and can survive. Therefore, superdormant spores need to be characterized to understand the causes of their germination deficiency. Bacillus subtilis spores were pressurized for 50 s - 6 min at a very high pressure (vHP) level of 550 MPa and 60 °C in buffer to trigger germination. For a rapid quantification of the remaining ungerminated superdormant spores, flow cytometry (FCM) analysis was validated using single cell sorting and growth analysis. FCM based on propidium iodide (PI) and SYTO16 can be used for 550 MPa-superdormant spores after short vHP treatments of ≤1 min and post-HP incubation at 37 °C or 60 °C. The need for a post-HP incubation is particular for vHP treatments. The incubation was successful to separate FCM signals from superdormant and germinated spores, thus allowing superdormant spore quantification. The SYTO16 and PI fluorescence levels did not necessarily indicate superdormancy or apparent viability. This highlights the general need for FCM validation for different HP treatment conditions. The ∼7 % of ungerminated, i.e., superdormant, spores were isolated after a vHP treatment (550 MPa, 60 °C, 43-52 s). This allowed the characterization of vHP superdormant spores for the first time. The superdormant spores had a similar dipicolinic acid content as spores of the initial dormant population. Descendants of superdormant spores had a normal vHP germination capacity. The causes of vHP superdormancy were thus unlikely linked to the dipicolinic acid content or a permanent genetic change. Isolated superdormant spores germinated better in a second vHP treatment compared to the initial spore population. This has not been observed for other germination stimuli so far. In addition, the germination capacity of the initial spore population was time-dependent. A vHP germination deficiency can therefore be lost over time and seems to be caused by transient factors. Permanent cellular properties played a minor role as causes of superdormancy under chosen HP treatment conditions. The study gained new fundamental insights in vHP superdormancy which are of applied interest. Understanding superdormancy helps to efficiently develop a strategy to avoid superdormant spores and hence to inactivate all spores. The development of a mild HP spore germination-inactivation process aims at better preserving the food quality.

15.
Curr Biol ; 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38971148

RESUMEN

Seed germination represents a determinant for plants to enter ecosystems and is thus regarded as a key ecological and agronomic trait. It is tightly regulated by a variety of environmental cues to ensure that seeds germinate under favorable conditions. Here, we characterize BBX32, a B-box zinc-finger protein, as an imbibition-stimulated positive regulator of seed germination. Belonging to subgroup V of the BBX family, BBX32 exhibits distinct characteristics compared with its close counterparts within the same subgroup. BBX32 is transiently induced at both the transcriptional and post-transcriptional levels in the embryo upon water absorption. Genetic evidence indicates that BBX32 acts upstream of the master transcription factor PHYTOCHROME-INTERACTING FACTOR 1 (PIF1) to facilitate light-induced seed germination. BBX32 directly interacts with PIF1, suppressing its protein-interacting and DNA-binding capabilities, thereby relieving PIF1's repression on seed germination. Furthermore, the imbibition-stimulated BBX32 functions in parallel with the light-induced transcription regulator HFR1 to collectively attenuate the transcriptional activities of PIF1. The BBX32-PIF1 de-repression module serves as a molecular connection that enables plants to integrate signals of water availability and light exposure, effectively coordinating the initiation of seed germination.

16.
BMC Biotechnol ; 24(1): 46, 2024 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-38971771

RESUMEN

BACKGROUND: Microbial growth during plant tissue culture is a common problem that causes significant losses in the plant micro-propagation system. Most of these endophytic microbes have the ability to propagate through horizontal and vertical transmission. On the one hand, these microbes provide a rich source of several beneficial metabolites. RESULTS: The present study reports on the isolation of fungal species from different in vitro medicinal plants (i.e., Breynia disticha major, Breynia disticha, Duranta plumieri, Thymus vulgaris, Salvia officinalis, Rosmarinus officinalis, and Ocimum basilicum l) cultures. These species were tested for their indole acetic acid (IAA) production capability. The most effective species for IAA production was that isolated from Thymus vulgaris plant (11.16 µg/mL) followed by that isolated from sweet basil plant (8.78 µg/mL). On screening for maximum IAA productivity, medium, "MOS + tryptophan" was chosen that gave 18.02 µg/mL. The macroscopic, microscopic examination and the 18S rRNA sequence analysis indicated that the isolate that given code T4 was identified as Neopestalotiopsis aotearoa (T4). The production of IAA by N. aotearoa was statistically modeled using the Box-Behnken design and optimized for maximum level, reaching 63.13 µg/mL. Also, IAA extract was administered to sweet basil seeds in vitro to determine its effect on plant growth traits. All concentrations of IAA extract boosted germination parameters as compared to controls, and 100 ppm of IAA extract exhibited a significant growth promotion effect for all seed germination measurements. CONCLUSIONS: The IAA produced from N. aotearoa (T4) demonstrated an essential role in the enhancement of sweet basil (Ocimum basilicum) growth, suggesting that it can be employed to promote the plant development while lowering the deleterious effect of using synthetic compounds in the environment.


Asunto(s)
Endófitos , Germinación , Ácidos Indolacéticos , Ocimum basilicum , Semillas , Thymus (Planta) , Ocimum basilicum/microbiología , Thymus (Planta)/química , Ácidos Indolacéticos/metabolismo , Endófitos/fisiología , Endófitos/metabolismo , Endófitos/aislamiento & purificación , Endófitos/genética , Germinación/efectos de los fármacos , Semillas/microbiología , Semillas/crecimiento & desarrollo , Semillas/efectos de los fármacos
17.
Plant Biol (Stuttg) ; 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38979780

RESUMEN

The rare and threatened Heliosciadium repens grows in moist grasslands and has a distinct life cycle. Plants reproduce both clonally, although ramets tend to be short-lived, and sexually, with seeds that can form a persistent soil seed bank. The germination requirements of H. repens were investigated, yielding important information for its habitat management and conservation. We examined the soil seed bank in three populations and carried out germination experiments and embryo growth measurements with fresh seeds in laboratory, greenhouse and outdoor conditions. We also investigated the effects of storage and burial of seeds. H. repens formed a long-term persistent (>6 years) soil seed bank with very pronounced primary dormancy, but no secondary dormancy or dormancy cycles. Seeds can germinate throughout the growing season when temperatures are sufficiently high. Embryo growth and seed germination are triggered by light and, to a lesser extent, daily temperature fluctuations. Seeds of H. repens seem to have developed a unique germination syndrome with several strategies to remain dormant in the soil until optimal conditions are present for seedling establishment and survival. Both sexual reproduction and seed bank formation are crucial for the long-term survival of the populations.

18.
J Sci Food Agric ; 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38979987

RESUMEN

BACKGROUND: This study investigated the effects of γ-aminobutyric acid (GABA) combined with ultrasonic stress germination (AUG) treatment on the phenolic content and antioxidant activity of highland barley (HB). Key variables, including germination times (ranging from 0 to 96 h), ultrasonic power (200-500 W), and GABA concentration (5-20 mmol/L), were optimized using response surface methodology (RSM) to enhance the enrichment of phenolic compounds. Furthermore, the study assessed the content, composition, and antioxidant activities of phenolic compounds in HB under various treatment conditions such as germination alone (G), ultrasonic stress germination (UG), and AUG treatment. RESULTS: The study identified optimal conditions for the phenolic enrichment of HB, which included a germination time of 60 h, an ultrasound power of 300 W, and a GABA concentration of 15 mmol L-1. Under these conditions, the total phenolic content (TPC) in HB was measured at 7.73 milligrams of gallic acid equivalents per gram dry weight (mg GAE/g DW), representing a 34.96% enhancement compared to untreated HB. Notably, all treatment modalities - G, UG, and AUG - significantly increased the phenolic content and antioxidant activity in HB, with the AUG treatment proving to be the most effective. CONCLUSION: These obtained results suggest that AUG treatment is a promising processing method for enriching phenolic compounds and improving antioxidant activity in HB. Subsequently, the AUG-treated HB can be used to develop phenolic-rich germinated functional foods to further broaden the application of HB. © 2024 Society of Chemical Industry.

19.
Curr Res Food Sci ; 8: 100780, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38957286

RESUMEN

Sorghum starch granules are encapsulated in a rigid protein matrix that prevents the granules from fully swelling and gelatinizing. Sprouting and subsequent drying treatment can affect the gelatinization properties of sorghum starch. This study aimed to evaluate the gelatinization properties of flours from unsprouted (US) and sprouted (S50, S40) sorghum dried at 50 °C (6h) and 40 °C (12h), respectively. Swelling power (Sp), thermal properties (DSC) and 1H molecular mobility and dynamics were evaluated at different water contents (38-91%). Sp increased with increasing water content, with S40 showing the lowest values, probably due to prolonged amylase activity and thus starch breakdown. Sprouting increased gelatinization temperatures; however, these differences disappeared for high water contents (82 and 91%). From a molecular point of view, sprouted samples showed a decrease in protons associated to the rigid protein matrix and starch structures. 1H CPMG results showed the presence of 4 populations at 38% water content. The evolution of the more mobile population with increasing water content supported the assignment of more mobile water fraction to this population. Sprouting decreased the mobility of populations in unheated samples, suggesting an increase in molecular bonds between flour biopolymers and water. After heating, however, increased molecular mobility in S40 indicated the formation of a weaker network between starch, protein, and water at the molecular level. These results suggest that post-sprouting drying treatment influences sorghum gelatinization, with potential modulation by water content. This study contributes to understanding the application of sprouted sorghum in foods with different moisture content.

20.
Plant Foods Hum Nutr ; 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38976203

RESUMEN

Andean crops such as quinoa, amaranth, cañihua, beans, maize, and tarwi have gained interest in recent years for being gluten-free and their high nutritional values; they have high protein content with a well-balanced essential amino acids profile, minerals, vitamins, dietary fiber, and antioxidant compounds. During the germination bioprocess, the seed metabolism is reactivated resulting in the catabolism and degradation of macronutrients and some anti-nutritional compounds. Therefore, germination is frequently used to improve nutritional quality, protein digestibility, and availability of certain minerals and vitamins; furthermore, in specific cases, biosynthesis of new bioactive compounds could occur through the activation of secondary metabolic pathways. These changes could alter the technological and sensory properties, such as the hardness, consistency and viscosity of the formulations prepared with them. In addition, the flavor profile may undergo improvement or alteration, a critical factor to consider when integrating sprouted grains into food formulations. This review summarizes recent research on the nutritional, technological, functional, and sensory changes occur during the germination of Andean grains and analyze their potential applications in various food products.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA