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1.
Food Chem ; 338: 127803, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32822899

RESUMO

Quercus acorns have been used as a staple food since archeological times; currently, there is a renewed interest in the direct use of the acorns as nuts or as a source of consumable flour. In this regard, the phytochemical composition and variability of various morphotypes of acorns from Quercus ilex have been determined by using two platforms, near infrared spectroscopy (NIRS) and mass spectrometry (MS)-based metabolomics. According to NIRS, starch was the most abundant compound (50-60%). UHPLC-QToF analysis was used for untargeted metabolomic analysis and 192 metabolites were annotated. Principal component analysis (PCA) discriminated the morphotypes; 50 compounds out of 192 identified had the highest load over the first two PCA components (explaining 67.2% variability) and can be potential markers of variability. The data presented here support the value of acorns as a source of nutritionally rich compounds thus justifying their use a good alternative to other nuts.


Assuntos
Compostos Fitoquímicos/análise , Quercus/química , Sementes/química , Sementes/fisiologia , Cromatografia Líquida de Alta Pressão , Análise de Componente Principal , Quercus/metabolismo , Sementes/anatomia & histologia , Espectroscopia de Luz Próxima ao Infravermelho , Amido/análise , Espectrometria de Massas em Tandem
2.
Food Chem ; 340: 127937, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32889215

RESUMO

The objective of this study was to investigate differentially abundant proteins (DAPs) of wheat seeds produced under two nitrogen levels (0 and 240 kg/ha) before and after germination. We selected samples at 8 and 72 h after imbibition (HAI) to identify DAPs by iTRAQ. The results showed 190 and 124 DAPs at 8 and 72 HAI, respectively. Alpha-gliadin and chlorophyll a-b binding protein showed the biggest difference in abundance before and after germination. In GO enrichment analysis, the most significantly enriched GO term was nutrient reservoir activity at 8 HAI and endopeptidase inhibitor activity at 72 HAI. Moreover, many DAPs involved in mobilization of stored nutrients and photosynthesis were mapped to KEGG pathways. Dough development time, dough stability time and seedling chlorophyll content under N240 were significantly higher than those under N0, which validated the results of proteomic analysis. These results are crucial for food nutrition and food processing.


Assuntos
Germinação , Proteínas de Plantas/metabolismo , Sementes/fisiologia , Triticum/fisiologia , China , Clorofila A/metabolismo , Gliadina/metabolismo , Nitrogênio/metabolismo , Proteínas de Plantas/análise , Proteômica/métodos , Plântula/metabolismo , Sementes/metabolismo , Triticum/metabolismo
3.
PLoS One ; 15(9): e0238448, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32986744

RESUMO

Exposure to lead (Pb) can have serious toxic effects on the physiological and biochemical processes of plants. The chemical form of the metal determines the degree of its toxicity. In our research, we examined the effect of lead in the form of lead nitrate [Pb(NO3)2] and lead chloride (PbCl2) in concentrations of 12.5 mM and 25 mM on pine (Pinus sylvestris) seed germination. Nitrogen salt causes more severe changes than chloride salt. Increasing levels of electrolyte leakage, malondialdehyde, and hydrogen peroxide were detected during germination processes. The high levels of ROS lead to redox changes in the cell. We observed a reduction in the level of the reduced form of glutathione (GSH), and at the same time observed increased levels of the oxidised form of glutathione (GSSG) depending on the concentration and also the time of exposure to lead compounds. At the beginning of germination processes, the effective non-enzymatic activity of the antioxidant cycle was dominant, and at the late stage the enzymatic activity was noticed in the presence of Pb compounds. CAT activity significantly increased after Pb compound exposition.


Assuntos
Pinus sylvestris/metabolismo , Sementes/metabolismo , Antioxidantes/metabolismo , Germinação/efeitos dos fármacos , Glutationa/metabolismo , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/farmacologia , Chumbo/toxicidade , Malondialdeído/análise , Malondialdeído/farmacologia , Nitratos/toxicidade , Oxirredução , Pinus sylvestris/fisiologia , Espécies Reativas de Oxigênio , Sementes/fisiologia , Cloreto de Sódio
4.
PLoS One ; 15(9): e0238362, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32877452

RESUMO

Water and nutrient absorption from soil by crops mainly depend on the morphological traits and distribution of the crop roots. Dense planting with reduced nitrogen is a sustainable strategy for improving grain yield and nitrogen use efficiency. However, there is little information on the effects of dense planting with reduced nitrogen on direct-seeded inbred rice. Two-year field experiments were conducted with minirhizotron techniques to characterize the root morphological traits and distributions under different nitrogen application rates and sowing densities in two representative inbred rice varieties, Huanghuazhan (HHZ) and Yuenongsimiao (YNSM), grown under three nitrogen application rates (N0: 0 kg ha-1, LN: 135 kg ha-1, HN: 180 kg ha-1) and two sowing densities (LD: 18.75 kg ha-1, HD: 22.5 kg ha-1). Our study showed that dense planting with low nitrogen improved grain yield partly due to the increased panicle number. The higher sowing density with low nitrogen significantly affected the total root number (TRN), total root length (TRL), total root surface area (TRSA), and total root volume (TRV). There was a significant positive correlation between grain yield and TRL in the 10-20-cm soil layer (P < 0.05). The root morphological indexes were positively correlated with dry matter accumulation (P < 0.05) and negatively correlated with nitrogen content (P < 0.05) at the maturity stage. This study showed that a high sowing density with low nitrogen application can improve root morphology and distribution and increase grain yield and nitrogen use efficiency in direct-seeded inbred rice.


Assuntos
Nitrogênio/farmacologia , Oryza/fisiologia , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/fisiologia , Sementes/fisiologia , Solo/química , Água/química , Oryza/efeitos dos fármacos , Fenótipo , Raízes de Plantas/efeitos dos fármacos , Estações do Ano , Sementes/efeitos dos fármacos
5.
PLoS One ; 15(8): e0227528, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841235

RESUMO

The morphology and physiology of diaspores play crucial roles in determining the fate of seeds in unpredictable habitats. In some genera of the Brassicaceae different types of diaspores can be found. Lepidium appelianum produces non-dormant seeds within indehiscent fruits while in L. campestre dormant seeds are released from dehiscent fruits. We investigated whether the allocation of relevant defence compounds into different tissues in different Lepidium species may be related to the diverse dispersal strategy (indehiscent and dehiscent) and seed physiology (non-dormant and dormant). Total glucosinolate concentration and composition were analysed in immature and mature seeds and pericarps of L. appelianum and L. campestre using high-performance liquid chromatography. Moreover, for comparison, transgenic RNAi L. campestre lines were used that produce indehiscent fruits due to silencing of LcINDEHISCENCE, the INDEHISCENCE ortholog of L. campestre. Total glucosinolate concentrations were lower in immature compared to mature seeds in all studied Lepidium species and transgenic lines. In contrast, indehiscent fruits of L. appelianum maintained their total glucosinolate concentration in mature pericarps compared to immature ones, while in dehiscent L. campestre and in indehiscent RNAi-LcIND L. campestre a significant decrease in total glucosinolate concentrations from immature to mature pericarps could be detected. Indole glucosinolates were detected in lower abundance than the other glucosinolate classes (aliphatic and aromatic). Relatively high concentrations of 4-methoxyindol-3-ylmethyl glucosinolate were found in mature seeds of L. appelianum compared to other tissues, while no indole glucosinolates were detected in mature diaspores of L. campestre. The diaspores of the latter species may rather depend on aliphatic and aromatic glucosinolates for long-term protection. The allocation patterns of glucosinolates correlate with the morpho-physiologically distinct fruits of L. appelianum and L. campestre and may be explained by the distinct dispersal strategies and the dormancy status of both species.


Assuntos
Glucosinolatos/metabolismo , Lepidium/fisiologia , Sementes/metabolismo , Brassicaceae/fisiologia , Cromatografia Líquida de Alta Pressão/métodos , Ecossistema , Frutas/metabolismo , Frutas/fisiologia , Germinação/fisiologia , Lepidium/crescimento & desenvolvimento , Dormência de Plantas , Sementes/fisiologia , Água
6.
Plant Mol Biol ; 104(4-5): 513-527, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32833149

RESUMO

KEY MESSAGE: Os4BGlu14, a monolignol ß-glucosidase, plays a negative role in seed longevity by affecting primary metabolism during seed development and aging. Seed longevity is a crucial trait in agriculture and in the conservation of germplasm resources. ß-Glucosidases (BGlus) are multifunctional enzymes that affect plant growth and their adaptation to the environment. The function of rice BGlus in seed longevity, however, remains unknown. We report here that Os4BGlu14, a rice ß-Glucosidase, negatively affected seed longevity during accelerated aging. Os4BGlu14 was highly expressed in rice embryos and induced by accelerated aging. Compared to the wild type, rice lines overexpressing Os4BGlu14 had significantly greater grain length, but smaller grain width and thickness. Overexpressing (OE) lines also showed lower starch but higher glucose contents. After accelerated aging treatment, OE lines displayed a significantly lower germination percentage than the wild type. Additionally, these lines had higher lignin accumulation before and after accelerated aging. Metabolome analysis detected 217 metabolites in untreated and aged rice seeds. Comparison of the differential metabolites between WT and OE5 revealed that ten key metabolites, four of which (e.g., uridine 5'-diphosphoglucose-glucose, UDPG) were increased, while the other six (e.g., γ-aminobutyric acid and methionine) were decreased, might be the crucial factors that lead to seed deterioration. Further analysis confirmed higher UDPG levels and more severe programmed cell death in OE lines than in the wild type. Furthermore, OE lines presented a lower germination rate after abscisic acid and paclobutrazol treatment during germination, compared to the wild type. Our study provides a basis for understanding the function of Os4BGlu14 in seed longevity in rice.


Assuntos
Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Sementes/fisiologia , beta-Glucosidase/genética , Ácido Abscísico/farmacologia , Morte Celular , Regulação da Expressão Gênica de Plantas , Germinação/efeitos dos fármacos , Lignina/genética , Lignina/metabolismo , Metaboloma , Estresse Oxidativo/fisiologia , Células Vegetais/fisiologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Sementes/metabolismo , Uridina Difosfato Glucose/metabolismo , beta-Glucosidase/metabolismo
7.
J Plant Res ; 133(6): 855-872, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32797387

RESUMO

Seed priming increases the vigor of seeds and seedlings through metabolic and biochemical processes occurring during controlled hydration, followed by dehydration. In the field, seeds are exposed to hydration-dehydration events in and on the soil after dispersal, as in seed priming. Nevertheless, seed priming has been sparsely tested on desiccation-sensitive seeds, which are vulnerable to climate change effects. We evaluated the effect of two priming methods on seeds from two tropical rainforest species: Cupania glabra and Cymbopetalum baillonii. For hydropriming, the seeds were fully hydrated and then dehydrated to three dehydration levels. For natural priming, the seeds were buried for 12 days in either closed forest or forest gap. Primed seeds were sown in 1% agar medium and placed in an environmental chamber. The growth of the seedlings from the highest germination priming treatments was evaluated for 1 year in the field. Our results showed that for C. glabra and C. baillonii, hydroprimed seeds varied in their germination response, depending on the degree of their dehydration. However, for C. baillonii, hydropriming seems to invigorate seeds, compared to non-imbibed seeds of the same dehydration level. Natural priming increased germination speed in both species without any difference between closed forest and forest gap. Moreover, seeds with natural priming had a higher final germination percentage than seeds with hydropriming. Seedlings from seeds with natural priming showed a higher growth rate than the controls in both species, whereas hydropriming produced a similar effect in C. glabra. Both priming methods could be used for restoration practices with the studied species, natural priming being a novel method. The ecological implications of priming in desiccation sensitive seeds are discussed in this study.


Assuntos
Annonaceae/fisiologia , Germinação , Floresta Úmida , Sapindaceae/fisiologia , Plântula/crescimento & desenvolvimento , Sementes/fisiologia , Dessecação , México
8.
Nat Commun ; 11(1): 3201, 2020 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-32581263

RESUMO

Humans cultivate thousands of economic plants (i.e. plants with economic value) outside their native ranges. To analyze how this contributes to naturalization success, we combine global databases on economic uses and naturalization success of the world's seed plants. Here we show that naturalization likelihood is 18 times higher for economic than non-economic plants. Naturalization success is highest for plants grown as animal food or for environmental uses (e.g. ornamentals), and increases with number of uses. Taxa from the Northern Hemisphere are disproportionately over-represented among economic plants, and economic plants from Asia have the greatest naturalization success. In regional naturalized floras, the percentage of economic plants exceeds the global percentage and increases towards the equator. Phylogenetic patterns in the naturalized flora partly result from phylogenetic patterns in the plants we cultivate. Our study illustrates that accounting for the intentional introduction of economic plants is key to unravelling drivers of plant naturalization.


Assuntos
Agricultura , Espécies Introduzidas/economia , Fenômenos Fisiológicos Vegetais , Agricultura/economia , Biodiversidade , Conservação dos Recursos Naturais , Geografia , Filogenia , Plantas/classificação , Sementes/classificação , Sementes/fisiologia , Especificidade da Espécie
9.
Food Chem ; 331: 127354, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32569973

RESUMO

Polyphenols (flavonoids and anthraquinones) are one of the most important phytochemicals in Fagopyrum tataricum L. Gaertn. (tartary buckwheat). However, the relationship between the polyphenols of tartary buckwheat seeds and their morphological variations is unclear. We developed a liquid chromatography-mass spectrometry-based targeted metabolomics method to study the chemical profiles of 60 flavonoids and 11 anthraquinones in 40 seed cultivars (groats and hulls). Both flavonoids and anthraquinones were related to variations in seed color; the fold change from yellowish-brown to black seeds was 1.24-1.55 in groats and 0.26-0.76 in hulls. Only flavonoids contributed to significant differences in seed shape; the fold change from long to short seeds was 1.29-1.78 in groats and 1.39-1.44 in hulls. Some differential metabolites were identified at higher concentrations in hulls than in groats. This study provides new insights into differences in polyphenols among tartary buckwheat seeds with different color and shape.


Assuntos
Antraquinonas/análise , Fagopyrum/metabolismo , Flavonoides/análise , Metabolômica/métodos , Sementes/fisiologia , Antraquinonas/metabolismo , Cromatografia Líquida/métodos , Fagopyrum/química , Flavonoides/metabolismo , Análise de Alimentos/métodos , Pigmentação , Metabolismo Secundário , Sementes/química , Sementes/metabolismo , Espectrometria de Massas em Tandem
10.
Sci Rep ; 10(1): 8855, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483323

RESUMO

With millions of years' evolution, plants and fungi have developed a variety of ballistic dispersal structures for seeds or spores. One typical example is the catapult of an Oxalis sp., which can realize a consecutive seed ejection by triggering only one seed. If the protrusion on an aril, a specialized outgrowth covering a seed, is disturbed, cracks would occur and cause the opening of the aril. Subsequently, the whole aril snaps and transforms its stored strain energy to eject the inside seed with an optimal launching angle. Once the first seed is triggered, its curly aril will contact the next seed's protrusion and induce its firing. This chain effect will further trigger the remaining seeds in turns, within 0.1 s. Inspired by this phenomenon, we invented a bionic ejection device to launch projectiles with high efficiency. This exploration is promising for a number of applications, such as drug delivery and oil displacement.


Assuntos
Oxalidaceae/fisiologia , Dispersão de Sementes/fisiologia , Frutas/fisiologia , Oxalidaceae/crescimento & desenvolvimento , Sementes/química , Sementes/fisiologia
11.
PLoS One ; 15(5): e0232875, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32407357

RESUMO

Water uptake into seeds is a fundamental prerequisite of germination and commonly influenced by commercial seed enhancement technologies. The effect of fruit orientation and contrasting pelleting materials on germination and biological performance of sugar beet was assessed. The results indicated there was orientation dependent fruit shrinkage of 37% for the operculum side supplied by moisture compared to 4% for the basal pore side. The expansion rate of 5% compared to the original size, which was also observed for non-shrinking seeds, indicated this was a temporary effect. This behaviour has importance for the application pelleting materials to seeds. Pellets composed of materials exhibiting low levels of swelling act as a water distribution layer which increased germination rates. Careful selection of pelleting material is crucial as it has direct implications on germination speed and subsequent establishment rates.


Assuntos
Agricultura/métodos , Beta vulgaris/fisiologia , Frutas/química , Germinação , Sementes/fisiologia , Açúcares/metabolismo , Água/metabolismo , Beta vulgaris/química , Beta vulgaris/crescimento & desenvolvimento , Frutas/fisiologia , Orientação Espacial , Sementes/química , Sementes/crescimento & desenvolvimento
12.
J Plant Physiol ; 250: 153184, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32464590

RESUMO

Although it is well known that parasitic weeds such as Orobanche (broomrape) significantly reduce the yield of economically important crops, their infection-induced oxidative changes need more exploration in their host plants. Moreover, applying an eco-friendly approach to minimize the infection is not yet available. This study was conducted to understand the effect of Orobanche ramosa infection on oxidative and redox status of tomato plants and the impact of hormonal (indole acetic acid (IAA); 0.09 mM and salicylic acid (SA); 1.0 mM) seed-priming upon mitigating the infection threats. Although Orobanche invades tomato roots, its inhibitory effects on shoot biomass were also indicted. Orobanche infection usually induces oxidative damage i.e., high lipid peroxidation, lipoxygenase activity and H2O2 levels, particularly for roots. Interestingly, hormonal seed-priming significantly enhanced tomato shoots and roots growth under both healthy and infected conditions. Also, IAA and SA treatment significantly reduced Orobanche infection-induced oxidative damage. The protective effect of seed-priming was explained by increasing the antioxidant defense markers including the antioxidant metabolites (i.e., total antioxidant capacity, carotenoids, phenolics, flavonoids, ASC, GSH, tocopherols) and enzymes (CAT, POX, GPX, SOD, GR, APX, MDHAR, DHAR), particularly in infected tomato seedlings. Additionally, cluster analysis indicated the differential impact of IAA- and SA-seed-priming, whereas lower oxidative damage and higher antioxidant enzymes' activities in tomato root were particularly reported for IAA treatment. The principal component analysis (PCA) also proclaimed an organ specificity depending on their response to Orobanche infection. Collectively, here and for the first time, we shed the light on the potential of seed-priming with either IAA or SA to mitigate the adverse effect of O. ramosa stress in tomato plants, especially at oxidative stress levels.


Assuntos
Ácidos Indolacéticos/farmacologia , Lycopersicon esculentum/fisiologia , Orobanche/fisiologia , Estresse Oxidativo/fisiologia , Reguladores de Crescimento de Planta/farmacologia , Plantas Daninhas/fisiologia , Ácido Salicílico/farmacologia , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/parasitologia , Estresse Oxidativo/efeitos dos fármacos , Sementes/efeitos dos fármacos , Sementes/parasitologia , Sementes/fisiologia
13.
PLoS One ; 15(4): e0232159, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32339211

RESUMO

In this study, we investigated changes in the isoflavone content, total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities (DPPH, ABTS), and anti-inflammatory activities of small-seeded and large-seeded soybean cultivars during germination (light/dark conditions). Total isoflavone content was higher at the seed stage in large-seeded soybeans, while it increased after 7 days of germination in small-seeded soybeans, particularly in response to light conditions, under which they had high TPC, TFC, and antioxidant activities. In large-seeded soybeans, the germination environment did not significantly affect TFC or DPPH inhibition, whereas TPC and ABTS inhibition were high under dark germination conditions. Extracts of sprouts exhibited superior anti-inflammatory activities. Nitric oxide production was slightly lower in small-seeded and large-seeded soybeans germinated under light and dark conditions, respectively. Our findings indicate that germinated soybeans improved nutritionally, and that enhancement of bioactivity under different germination environments could contribute to the selection of appropriate soybean cultivars.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/metabolismo , Flavonoides/metabolismo , Germinação/fisiologia , Isoflavonas/metabolismo , Fenóis/metabolismo , Soja/metabolismo , Óxido Nítrico/metabolismo , Sementes/metabolismo , Sementes/fisiologia
14.
BMC Plant Biol ; 20(1): 127, 2020 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-32216758

RESUMO

BACKGROUND: Soybean developing seed is susceptible to high temperature and humidity (HTH) stress in the field, resulting in vigor reduction. Actually, the HTH in the field during soybean seed growth and development would also stress the whole plant, especially on leaf and pod, which in turn affect seed growth and development as well as vigor formation through nutrient supply and protection. RESULTS: In the present study, using a pair of pre-harvest seed deterioration-sensitive and -resistant cultivars Ningzhen No. 1 and Xiangdou No. 3, the comprehensive effects of HTH stress on seed vigor formation during physiological maturity were investigated by analyzing cotyledon, embryo, leaf, and pod at the levels of protein, ultrastructure, and physiology and biochemistry. There were 247, 179, and 517 differentially abundant proteins (DAPs) identified in cotyledon, embryo, and leaf of cv. Xiangdou No. 3 under HTH stress, while 235, 366, and 479 DAPs were identified in cotyledon, embryo, and leaf of cv. Ningzhen No. 1. Moreover, 120, 144, and 438 DAPs between the two cultivars were identified in cotyledon, embryo, and leaf under HTH stress, respectively. Moreover, 120, 144, and 438 DAPs between the two cultivars were identified in cotyledon, embryo, and leaf under HTH stress, respectively. Most of the DAPs identified were found to be involved in major metabolic pathways and cellular processes, including signal transduction, tricarboxylic acid cycle, fatty acid metabolism, photosynthesis, protein processing, folding and assembly, protein biosynthesis or degradation, plant-pathogen interaction, starch and sucrose metabolism, and oxidative stress response. The HTH stress had less negative effects on metabolic pathways, cell ultrastructure, and physiology and biochemistry in the four organs of Xiangdou No. 3 than in those of Ningzhen No. 1, leading to produce higher vigor seeds in the former. CONCLUSION: High seed vigor formation is enhanced by increasing protein biosynthesis and nutrient storage in cotyledon, stronger stability and viability in embryo, more powerful photosynthetic capacity and nutrient supply in leaf, and stronger protection in pod under HTH stress. These results provide comprehensive characteristics of leaf, pod and seed (cotyledon and embryo) under HTH stress, and some of them can be used as selection index in high seed vigor breeding program in soybean.


Assuntos
Cotilédone/fisiologia , Temperatura Alta , Umidade , Folhas de Planta/fisiologia , Sementes/fisiologia , Soja/fisiologia , Cotilédone/química , Folhas de Planta/química , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Sementes/química , Sementes/crescimento & desenvolvimento , Soja/química
15.
BMC Plant Biol ; 20(1): 104, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32138669

RESUMO

BACKGROUND: Loss of vigor caused by seed aging adversely affects agricultural production under natural conditions. However, priming is an economical and effective method for improving the vigor of aged seeds. The objective of this study was to test the effectiveness of exogenous ascorbic acid (ASC) and glutathione (GSH) priming in the repairing of aged oat (Avena sativa) seeds, and to test the hypothesis that structural and functional systems in mitochondria were involved in this process. RESULTS: Oat seeds were artificially aged for 20 days at 45 °C, and were primed with solutions (1 mmol L- 1) of ASC, GSH, or ASC + GSH at 20 °C for 0.5 h before or after their aging. Seed germination, antioxidant enzymes in the ASC-GSH cycle, cytochrome c oxidase (COX) and mitochondrial malate dehydrogenase (MDH) activities, and the mitochondrial ultrastructures of the embryonic root cells were markedly improved in aged oat seeds through post-priming with ASC, GSH, or ASC + GSH, while their malondialdehyde and H2O2 contents decreased significantly (P < 0.05). CONCLUSION: Our results suggested that priming with ASC, GSH, or ASC + GSH after aging could effectively alleviate aging damage in oat seeds, and that the role of ASC was more effective than GSH, but positive effects of post-priming with ASC and GSH were not superior to post-priming with ASC in repairing aging damage of aged oat seeds. However, pre-priming with ASC, GSH, or ASC + GSH was not effective in oat seeds, suggesting that pre-priming with ASC, GSH, or ASC + GSH could not inhibit the occurrence of aging damage in oat seeds.


Assuntos
Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Avena/fisiologia , Glutationa/metabolismo , Mitocôndrias/efeitos dos fármacos , Antioxidantes/administração & dosagem , Ácido Ascórbico/administração & dosagem , Avena/efeitos dos fármacos , Glutationa/administração & dosagem , Mitocôndrias/metabolismo , Sementes/efeitos dos fármacos , Sementes/fisiologia
16.
Food Chem ; 318: 126483, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32126468

RESUMO

In this study, the antioxidant activity of germinating Chinese wild rice was found to decline initially, after which it increased. The largest difference in antioxidant activity was observed between the 36-h (G36) and the 120-h germination (G120) stage. We further assessed the dynamic changes in metabolites, phenolic acids, flavonoids, and phenolic biosynthetic genes in germinating Chinese wild rice. Ultra-high performance liquid chromatography-triple quadrupole mass spectrometry revealed that 315 metabolites were up-regulated and 28 were down-regulated between G36 and G120. Levels of p-hydroxybenzoic acid, p-hydroxybenzaldehyde, vanillin, p-coumaric acid, ferulic acid, and epigallocatechin increased significantly during germination. Gene expression of four phenylalanine ammonia-lyases, one 4-coumarate-CoA ligase, one cinnamoyl-CoA reductase, two cinnamyl alcohol dehydrogenases, one chalcone synthase, and one chalcone isomerase was significantly higher at G120 than at G36 and promoted phenolics accumulation. This study elucidated the biochemical mechanisms involved in antioxidant activity and phenolic profile changes during Chinese wild rice germination.


Assuntos
Antioxidantes/metabolismo , Flavonoides/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Fenóis/metabolismo , Proteínas de Plantas/genética , Poaceae/fisiologia , Aciltransferases/genética , Cromatografia Líquida de Alta Pressão , Coenzima A Ligases/genética , Germinação , Hidroxibenzoatos/metabolismo , Liases Intramoleculares/genética , Espectrometria de Massas , Oxirredutases/genética , Fenilalanina Amônia-Liase/genética , Poaceae/química , Poaceae/genética , Sementes/química , Sementes/genética , Sementes/fisiologia
17.
Plant Biol (Stuttg) ; 22(4): 745-749, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32141176

RESUMO

Dormancy cycling is a key mechanism that contributes to the maintenance of long-term persistent soil seed banks, but has not been recorded in long-lived woody shrub species from fire-prone environments. Such species rely on seed banks and dormancy break as important processes for post-fire recruitment and recovery. We used germination experiments with smoke treatments on fresh seeds and those buried for 1 year (retrieved in spring) and 1.5 years (retrieved the following late autumn) to investigate whether Asterolasia buxifolia, a shrub from fire-prone south-eastern Australia with physiologically dormant seeds, exhibited dormancy cycling. All seeds had an obligation for winter seasonal temperatures and smoke to promote germination, even after ageing in the soil. A high proportion of germination was recorded from fresh seeds. but germination after the first retrieval was significantly lower, despite high seed viability. After the second retrieval, germination returned to the initial level. This indicates a pattern of annual dormancy cycling; one of the few observations, to our knowledge, for a perennial species. Additionally, A. buxifolia's winter temperature and smoke requirements did not change over time, highlighting the potential for seeds to remain conditionally dormant (i.e. restricted to a narrow range of germination conditions) for long periods. For physiologically dormant species, such as A. buxifolia, we conclude that dormancy cycling is an important driver of successful regeneration, allowing seed bank persistence, sometimes for decades, during fire-free periods unsuitable for successful recruitment, while ensuring that a large proportion of seeds are available for recruitment when a fire occurs.


Assuntos
Fogo , Dormência de Plantas , Rutaceae , Sementes , Germinação , Dormência de Plantas/fisiologia , Rutaceae/fisiologia , Sementes/fisiologia , Solo , Temperatura
18.
Food Chem ; 319: 126597, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32187567

RESUMO

This research explored the application of combined radio frequency and hot air drying (RF-HAD) technology on corn seeds. Drying characteristics and seed vigor were investigated at different RF electrode gaps (140, 150 and 160 mm). To better demonstrate the feasibility of applying RF-HAD on corn seeds, tempering-intermittent hot air drying (HAD) was studied as a comparison. Reduced electrode gap corresponding to elevated average heating rate and power efficiency resulted in decreased seeds vigor and specific energy consumption. The assistance of RF significantly increased the drying rate of corn seeds and reduced drying duration by up to 70% compared with HAD. A higher dehydrogenase activity (DHA) but a lower germination percentage (GP) was observed in RF-HAD samples as compared with HAD ones. Corn seeds were promoted to be dormant by RF-HAD according to dormancy-breaking results and isobaric tags for relative and absolute quantification (iTRAQ) analysis.


Assuntos
Sementes/química , Sementes/fisiologia , Zea mays/química , Dessecação , Germinação , Calefação , Temperatura Alta , Oxirredutases/metabolismo , Dormência de Plantas , Ondas de Rádio , Zea mays/fisiologia
19.
Plant Biol (Stuttg) ; 22(4): 647-654, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32215992

RESUMO

Agricultural burning is used in farm management operations; however, information about the impact of fire cues on the release and/or induction of secondary dormancy in crop seeds is scarce. Seeds from two oilseed rape cultivars were induced for high (HD) or low (LD) secondary dormancy using polyethyleneglycol (PEG) pre-treatment, and their germination after exposure to various fire cues was compared to control PEG pre-treated and non-dormant seeds. Non-dormant seed germination was unaffected by various fire cues. Low doses of aerosol smoke released secondary dormancy in HD seeds, while higher doses increased dormancy of LD seeds. Dilute smoke water also released HD seed secondary dormancy, but concentrated smke water enhanced dormancy in both LD and HD seeds. The concentrated aqueous extracts from charred oilseed rape straw only promoted germination of HD seeds, while dilution inhibited LD seed germination. Heat shock (80 °C, 5 min) released secondary dormancy in HD seeds; however, higher temperatures and/or increased exposure time was associated with seed death. GC-MS analyses of smoke water revealed two butenolides and an array of monoaromatic hydroxybenzene compounds with potential germination inhibitor or promoter activity. The extent of secondary dormancy induction in seeds affects their subsequent responses to fire cues. Both aerosol smoke and smoke water have both germination promoter and inhibitor activity. Lacking any butenolides, aqueous extracts of charred straw contain a potential germination stimulating steroid, i.e. ergosterol. The significance of fire-derived cues on behaviour of oilseed rape seeds in the soil seed bank is discussed.


Assuntos
Brassica napus , Fogo , Germinação , Dormência de Plantas , Sementes , Brassica napus/fisiologia , Sinais (Psicologia) , Germinação/fisiologia , Sementes/fisiologia
20.
Plant Physiol Biochem ; 151: 124-131, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32220785

RESUMO

Seed germination and early seedling development are two critical phases in plant lifecycle that largely determine crop yield. Phytohormones play an essential role in governing these developmental processes; of these, ethylene (ET; C2H4), the smallest gaseous hormone, plays a major role via crosstalk with other hormones. Typically, the mechanism of hormone (for instance, auxin, cytokinins, ET, and gibberellins) action is determined by cellular context, revealing either synergistic or antagonistic relations. Significant progress has been made, so far, on unveiling ET crosstalk with other hormones and environmental signals, such as light. In particular, stimulatory and inhibitory effects of ET on hypocotyl growth in light and dark, respectively, and its interaction with other hormones provide an ideal model to study the growth-regulatory pathways. In this review, we aim at exploring the mechanisms of multifarious phenomena that occur via ET crosstalk during the germination of seeds (overcoming dormancy), and all through the development of seedlings. Understanding the remarkably complex mechanism of ET crosstalk that emerges from the interaction between hormones and other molecular players to modulate plant growth, remains a challenge in plant developmental biology.


Assuntos
Etilenos/metabolismo , Germinação , Plântula/fisiologia , Sementes/fisiologia , Transdução de Sinais , Reguladores de Crescimento de Planta/fisiologia
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