scholarly journals Activities of antioxidative enzymes during Chenopodium rubrum L. Ontogenesis in vitro

2008 ◽  
Vol 60 (2) ◽  
pp. 223-231 ◽  
Author(s):  
Aleksandra Mitrovic ◽  
Jelena Bogdanovic
Keyword(s):  
Seed Development ◽  
Antioxidative Enzymes ◽  
Continuous Light ◽  
Seed Maturation ◽  
Chenopodium Rubrum ◽  
Flowering Induction ◽  
Phases Of Development ◽  
Developmental Phases ◽  
Inductive Photoperiod

For the short-day plant Chenopodium rubrum, a 14 h/10 h photoperiod is inductive for flowering, while continuous light (CL) is noninductive. Plants of one group were grown continuously under an inductive photoperiod, while in the other group flowering induction was delayed by 17 days of CL in order to separate on the time scale different developmental phases in plants of the same age. Regardless of the photoperiodic conditions the plants were exposed to, seed maturation occurred in 10 weeks. Activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) were determined in different phases of development (vegetative growth, flowering, seed development, and maturation). The activities of antioxidative enzymes depended on both the phase of development and the photoperiod. In plants grown continuously under an inductive photoperiod, high CAT and POD activities were detected at the time of flowering and decreased during seed development and maturation. In plants in which flowering induction was delayed by 17 days of CL, the activities of POD and SOD were lowest in the vegetative phase of development and attained maximum values in the phase of seed maturation. In both groups of plants, the highest CAT activity was measured at the time of flowering.

scholarly journals The photoperiodic control of growth and development of Chenopodium rubrum L. plants in vitro

2007 ◽  
Vol 59 (3) ◽  
pp. 203-208 ◽  
Author(s):  
Aleksandra Mitrovic ◽  
Z. Giba ◽  
Ljubinka Culafic
Keyword(s):  
Life Cycle ◽  
Plant Growth ◽  
Seed Development ◽  
Growth And Development ◽  
Reproductive Development ◽  
Day Length ◽  
Chenopodium Rubrum ◽  
Development In Vitro ◽  
Photoperiod Sensitive

Influence of the photoperiod on growth, flowering, and seed development in vitro of Chenopodium rubrum L., a short day annual, was examined. Chenopodium rubrum plants modify their growth and reproductive development in accordance with the photoperiod. With an increase of day length, growth was stimulated, flowering was delayed, seed development occurred earlier, and the plants produced more seeds. By altering photoperiods during induction and evocation of flowering, it is shown that the photoperiod experienced by seedlings during early reproductive development determines the pattern of plant growth to the end of ontogenesis, the time to flowering, and the course of seed development. It is therefore concluded that growth and reproductive development of C. rubrum are photoperiod-sensitive to during a precise short part of its life cycle. .

Seed-borne fungi of cowpea [Vigna unguiculata (L.) Walp] and their possible control in vitro using locally available fungicides in Botswana.

2016 ◽  
Vol 5 (11) ◽  
pp. 5016 ◽  
Author(s):  
K. B. Khare* ◽  
Loeto D. ◽  
Wale K. ◽  
Salani M.
Keyword(s):  
Seed Germination ◽  
Continuous Light ◽  
Sodium Hypochlorite Solution ◽  
Distilled Water ◽  
Percentage Germination ◽  
Department Of Agriculture ◽  
Hypochlorite Solution ◽  
Cowpea Cultivars ◽  
Petri Plate

Seeds of three cowpea cultivars namely Black eye, ER 7 and Tswana obtained from the Department of Agriculture Research, Gaborone were tested for the presence of seed-borne fungi, and their possible control in vitro using locally available fungicides. Four hundred fifty seeds of each cultivar of cowpea were disinfected with 2% sodium hypochlorite solution for 10 min and washed three times with sterile distilled water before placing them in PDA plates (5 seeds/9 cm Petri plate), incubated at 22±2o C for 12 hour each under continuous light and dark. A total of eight fungi were detected from seeds of cowpea. These were Aspergillus flavus, A. niger, Cylindrocarpon sp., Fusarium equisiti, F. oxyaporum, Penicillium chyrosogenum, Rhizopus oligosporus and R. stolonifer. Rhizopus spp. were dominant fungi recovered from seeds, followed by Penicillium, Aspergillus, Fusarium and Cylindrocarpon. The fungi detected resulted in decay and rotting of seeds, and thereby reducing percentage germination of seeds (22%, 37% and 63 % seed germination in Black eye, ER7 and Tswana varieties of cowpea respectively). Out of four fungicides tested, benlate, captan, dithane M 45 and chlorothalanil. Dithane M45 effectively controlled seed-borne fungi, and enhanced seed germination to an average of 86% (93% germination with no fungi detected in Tswana variety) as compared to chlorothalonile (79%), benlate and captan (77%) and un-treated seeds (45%). The fungal incidence was reduced to 2.3%, 4.3%, 5.3% and 5.3% when seeds were treated with dithane M-45, chlorothalonil, benlate and captan respectively as compared to 62% in non-treated seeds.

scholarly journals LEAFY COTYLEDON1 expression in the endosperm enables embryo maturation in Arabidopsis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jingpu Song ◽  
Xin Xie ◽  
Chen Chen ◽  
Jie Shu ◽  
Raj K. Thapa ◽  
...  
Keyword(s):  
Seed Development ◽  
Embryo Development ◽  
Growth Regulators ◽  
Seed Maturation ◽  
Embryo Maturation ◽  
Leafy Cotyledon1 ◽  
Functional Relevance ◽  
Necessary And Sufficient ◽  
Zygote Stage

AbstractThe endosperm provides nutrients and growth regulators to the embryo during seed development. LEAFY COTYLEDON1 (LEC1) has long been known to be essential for embryo maturation. LEC1 is expressed in both the embryo and the endosperm; however, the functional relevance of the endosperm-expressed LEC1 for seed development is unclear. Here, we provide genetic and transgenic evidence demonstrating that endosperm-expressed LEC1 is necessary and sufficient for embryo maturation. We show that endosperm-synthesized LEC1 is capable of orchestrating full seed maturation in the absence of embryo-expressed LEC1. Inversely, without LEC1 expression in the endosperm, embryo development arrests even in the presence of functional LEC1 alleles in the embryo. We further reveal that LEC1 expression in the endosperm begins at the zygote stage and the LEC1 protein is then trafficked to the embryo to activate processes of seed maturation. Our findings thus establish a key role for endosperm in regulating embryo development.

scholarly journals Gene expression profiling identifies pathways involved in seeds maturation of Jatropha curcas

2019 ◽  
Author(s):  
Fatemeh Maghuly ◽  
Tamas Deak ◽  
Klemens Vierlinger ◽  
Stephan Pabinger ◽  
Hakim Tafer ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Seed Development ◽  
Jatropha Curcas ◽  
Molecular Mechanisms ◽  
Seed Quality ◽  
Developmental Stages ◽  
Seed Maturation ◽  
Nutrient Mobilization ◽  
Starting Point ◽  
Maturation Stages

Abstract Background: Jatropha curcas, a tropical shrub, is a promising biofuel crop, which produces seeds with a high content of oil and protein. To better understand the development of its seeds to improve Jatropha`s agronomic performance, a two-step approach was performed: 1) generation of the entire transcriptome of six different maturation stages of J. curcas seeds using 454-Roche sequencing of a cDNA library, 2) comparison of transcriptional expression levels in six different developmental stages of seeds using a custom Agilent 8x60K oligonucleotide microarray. Results: A total of 793,875 high-quality reads were assembled into 19,841 unique full-length contigs, of which 13,705 could be annotated with Gene Ontology (GO) terms. Microarray data analysis identified 9,111 probes (out of 57,842 probes), which were differentially expressed between the six developmental stages. The expression results were validated for 70 randomly selected putative genes. Result from cluster analyses showed that transcripts related to sucrose, fatty acid, flavonoid, phenylpropanoid, lignin, hormone biosynthesis were over-represented in the early stage, while lipid storage, seed dormancy and maturation in the late stage. Generally, the expression of the most over-represented transcripts decrease in the last stage of seed maturation. Further, expression analyses of different maturation stages of J. curcas seed showed that most changes in transcript abundance occurred between the two last stages, suggesting that the timing of metabolic pathways during seed maturation in J. curcas is in late stages. The co-expression result showed a high degree of connectivity between genes that play essential role in fatty acid biosynthesis and nutrient mobilization. Furthermore, seed development and hormone pathways are significantly well connected. Conclusion: The obtained results revealed DESs regulating important pathways related to seed maturation, which could contribute to understanding the complex regulatory network during seed development. This study provides detailed information on transcription changes during J. curcas seed development and provides a starting point for a genomic survey of seed quality traits. The current results highlighted specific genes and processes relevant to the molecular mechanisms involved in Jatropha seed development, and it is anticipated that this data can be delivered to other Euphorbiaceae species of economic value.

scholarly journals A rapidly evolved shift in life history timing during ecological speciation is driven by the transition between developmental phases

2020 ◽  
Author(s):  
Thomas H. Q. Powell ◽  
Andrew Nguyen ◽  
Qinwen Xia ◽  
Jeffrey L. Feder ◽  
Gregory J. Ragland ◽  
...  
Keyword(s):  
Developmental Trajectories ◽  
Maintenance Phase ◽  
Adult Emergence ◽  
Physiological Basis ◽  
Data Accessibility ◽  
Seasonal Timing ◽  
Pupal Diapause ◽  
Phases Of Development ◽  
Diapause Development ◽  
Developmental Phases

AbstractFor insect species in temperate environments, seasonal timing is often governed by the regulation of diapause, a complex developmental program that allows insects to weather unfavorable conditions and synchronize their lifecycles with available resources. Diapause consists of a series of phases that govern initiation, maintenance, and termination of this developmental pathway. The evolution of insect seasonal timing depends in part on how these phases of diapause development and post-diapause development interact to affect variation in phenology. Here, we dissect the physiological basis of a recently evolved phenological shift in Rhagoletis pomonella (Diptera: Tephritidae), a model system for ecological divergence. A recently derived population of R. pomonella shifted from specializing on native hawthorn fruit to earlier fruiting introduced apples, resulting in a 3-4 week shift in adult emergence timing. We tracked metabolic rates of individual flies across post-winter development to test which phases of development may act either independently or in combination to contribute to this recently evolved divergence in timing. Apple and hawthorn flies differed in a number of facets of their post-winter developmental trajectories. However, divergent adaptation in adult emergence phenology in these flies was due almost entirely to the end of the pupal diapause maintenance phase, with post-diapause development having a very small effect. The relatively simple underpinnings of variation in adult emergence phenology suggest that further adaptation to seasonal change in these flies for this trait might be largely due to the timing of diapause termination unhindered by strong covariance among different components of post-diapause development.Data accessibilityAll data (in the form of tables of all metabolic rate measurements for all individual flies in the study) will be available on DRYAD when the manuscript is published.

Antibacterial Activity and Anti-Biofilm Effect of Chitosan against Strains of Streptococcus Mutans Isolated in Dental Plaque

2008 ◽  
Vol 21 (4) ◽  
pp. 993-997 ◽  
Author(s):  
G. Pasquantonio ◽  
C. Greco ◽  
M. Prenna ◽  
C. Ripa ◽  
L.A. Vitali ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Streptococcus Mutans ◽  
Dental Plaque ◽  
Chitosan Solution ◽  
Positive Control ◽  
Phases Of Development ◽  
Adhesion Phase ◽  
Adult Volunteers

Streptococcus mutans is the major cause of dental plaque and is often associated with biofilm formation. The aim of this study is to evaluate the activity of a hydrosoluble derivative of chitosan against S. mutans biofilms in vitro and in vivo. Strains of S. mutans were isolated from the dental plaque of 84 patients enrolled in the study. The antibacterial activity of chitosan was determined by broth microdilutions. The effect of chitosan at different concentrations and exposure times on S. mutans biofilms at different phases of development was assessed by a clinical study using the classical “4-day plaque regrowth” experiment in adult volunteers. The MIC values of chitosan were between 0.5 and 2 g/L. Compared to distilled water, the chitosan solution significantly decreased the vitality of plaque microflora (p≤0.05). Chlorhexidine, used as a positive control, reduced vitality even further. The results showed that S. mutans in the adhesion phase (4 h) was completely inhibited by chitosan at any concentration (0.1, 0.2, 0.5XMIC) or exposure time investigated (1, 15, 30, 60 min), while S. mutans at successive stages of accumulation (12–24 h) was inhibited only by higher concentrations and longer exposure times. These data confirm the effective action of chitosan against S. mutans biofilms.

Physical and physiological changes of Crambe abyssinica Hochst seed during maturation

2020 ◽  
Vol 42 ◽  
pp. e49895
Author(s):  
Ana Paula de Oliveira Silva ◽  
Isabella Sousa Ribeiro ◽  
Tathiana Elisa Masetto ◽  
Luiz Carlos Ferreira Souza
Keyword(s):  
Water Content ◽  
Seed Development ◽  
Germination Rate ◽  
Germination Percentage ◽  
Seed Maturation ◽  
Physiological Changes ◽  
Crambe Abyssinica ◽  
Mato Grosso ◽  
Physiological Quality ◽  
Physical Attributes

Determination of seed-maturation indicators enables the identification of the ideal moment for harvest to achieve the best production and conservation potential. Our objective here was to evaluate some physical and physiological changes of crambe (Crambe abyssinica Hochst) seeds as possible indicators of seed maturation. Crambe flowering was monitored in Dourados, Mato Grosso do Sul, Brazil. Plants were tagged, and 13, 22, 26, and 28 days after the initiation of flowering, the seeds were collected and following physical attributes evaluated: length, diameter, total mass, dry matter and water content. Physiological quality of the seeds was assessed using the germination test, by registering the percentage of normal seedlings and dormant seeds, immediately after each harvest, and again after six months of storage. The water-absorption curves were characterized as a function the seed-development stages. All physical attributes were observed to increase because of the accumulation of reserve substances during seed development, except for water content, which gradually decreased from 72.2% at the start of development to 29.5% at maturity. At 28 days after anthesis the germination percentage of crambe seeds at physiological maturity was only 17%, indicating that they became dormant while maturing. However, seed germination rate was 89% after six months of storage, indicating that dormancy was almost fully overcome after this period.

Causal Relationships among Metabolic Circadian Rhythms in Lemna

1984 ◽  
Vol 39 (1-2) ◽  
pp. 73-84 ◽  
Author(s):  
Ken Goto
Keyword(s):  
Circadian Rhythms ◽  
Kinase Activity ◽  
Continuous Light ◽  
Mirror Image ◽  
Nad Kinase ◽  
Long Day ◽  
Level Of Activity ◽  
Night Period

Abstract Biochemical aspects of circadian rhythms were studied using a long-day duckweed, Lemna gibba G3 cultured in short day condition (9 h light at 3800 lux followed by 15 h darkness), which was transferred in continuous light (LL) at the end (LL 0) of the last night period. With such a system I have previously reported a rhythm of affinity for NAD+ of cytoplasmic NAD - dependent glyceraldehyde 3-phosphate dehydrogenase (Cyt-NAD -GPD ) 180° out of phase with that of affinity for NADP+ of chloroplastic NADP-dependent GPD (Chl-NADP-GPD ) and that NADP+ could increase in vitro the affinity for NADP+ of Chl-NADP-GPD . I report here that NADP+ can decrease in vitro the affinity for NAD+ of Cyt-NAD -GPD as well, and furthermore, that the in vivo level of NADP+ oscillates in phase with the rhythm of the affinity for NADP+ of Chl-NADP-GPD. Moreover, I found the existence of mirror-image circadian rhythms, of comparable am plitudes, of in vivo levels of NAD+ + NADH (total NAD) (with peaks, as the ones of Cyt-NAD - GPD. at LL 0 and 24) and of NADP+ + NADPH (total NADP) (with peaks, as the ones of Chl-NADP-GPD, at LL 12 and 36). Consequently, a circadian rhythm in the rate of net in vivo production of total NADP (or NAD) might be expected 90° in advance of that in the level of total NADP (or NAD). Indeed. I found oscillations in the activities of NAD kinase and of NADP phosphatase with peaks occurring, respectively, at LL 6 and at LL 18. Moreover, in vitro treatments with EGTA (a Ca2+-chelator), chlorpromazine and W7 (both inhibitors of calmodulin) were able to both inhibit NAD kinase from its highest level of activity to its minimal one and activate NADP phosphatase from its lowest level of activity to its maximal one. I conclude, therefore, that the in vivo level of Ca2+-calmodulin could oscillate in phase with the rhythm of NAD kinase activity and induce the mirror-image circadian rhythms of activities of NAD kinase and of NADP phosphatase. I propose that the control sequence among the several circadian rhythms I studied could start with changes in Ca2+-calmodulin, then proceed through oscillations in NAD kinase and NADP phosphatase activities, leading to changes in NAD+, NADP+, and NADPH levels, which would themselves induce the Chl-NADP-GPD and Cyt-NAD -GPD rhythms.

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