Effect of visible light on animal biochemical and physiological parameters

The animals perception of the visible spectrum with waves length 450, 540, 680 nm of the same light intensity has been studied. The effect of visible light on rats has been estimated by some functional and biochemical parameters in vivo and in vitro. The whole complex of results obtained gives a chance to suppose that the light energy of visible spectrum redistribution in animal's tissues has a principal role in the regulation of animal's metabolism depending on the spectral structure of the incident light.     

Effects of bromocriptine on sweat gland function during heat acclimatization

This study examined the involvement of the hormones aldosterone and prolactin in sweat gland function during heat acclimatization. Two groups of male subjects (n = 8) were tested - one receiving a placebo (control), the other receiving bromocriptine. Both groups performed cycle ergometer exercise at 50% of maximal oxygen uptake over 10 consecutive days in an environmental chamber maintained at 39 degrees C and 30% relative humidity. Duration of exercise was 90 min on days 2-4 and 6-9, and 45 min on test days 1, 5 and 10. Electrolyte concentrations were determined by total body washdown. Prolactin increased (p less than 0.001) during exercise on day 1 in the control group but not on days 5 and 10. In contrast, prolactin was suppressed by bromocriptine and did not rise in response to exercise or heat exposure. Plasma aldosterone increased during exercise in both groups, showing no differences between groups. The sodium concentration in sweat decreased significantly (p less than 0.05) in the control group from day 1 to 10 but was unchanged in the treatment group. These data suggest that acclimatization-related changes in sweat gland function may be attenuated by increases in central dopaminergic activity and implicate prolactin in control of sweat gland function.     

Impact of sugar concentration in vitro on photosynthesis and carbon metabolism during ex vitro acclimatization of Spathiphyllum plantlets

Photosynthesis and carbon metabolism were followed during the acclimatization of micropropagated Spathiphyllum cv. Petite shootlets cultured with two different sucrose concentrations (3 and 6%). Increased sugar supply resulted in inhibition of photosynthesis, nonfunctional photosynthetic reaction centers, a more mixotrophic metabolism and higher starch and sucrose reserves at the end of the in vitro period. During the first days of acclimatization, net photosynthesis and adenosine diphosphoglucose (ADPG) pyrophosphorylase (EC 2.7.7.27) activity decreased for both treatments. In this period, sucrose was mainly used as nutrient reserve by plants cultured on 6% sucrose, as evidenced by a strong increase in sucrose synthase (EC 2.4.1.13) activity together with a severe decline in sucrose content. In the same period, sucrose breakdown and synthesis were in balance for plants cultured on 3% sucrose and the starch content increased slightly. After one week plants started to recover and full photosynthetic capacity developed. Two weeks after ex vitro transplantation, no differences between plants micropropagated with 3 or 6% sucrose could be found for photosynthesis, carbohydrate pools or enzyme activities. At the end of acclimatization the starch content increased again.     

Photosynthetic parameters of Ulmus minor plantlets affected by irradiance during acclimatization

In order to set up large-scale acclimatization protocols of micropropagated plants, an in-depth knowledge of their physiological responses during in vitro to ex vitro transfer is required. This work describes the photosynthetic performance of Ulmus minor micropropagated plants during acclimatization at high irradiance (HI; 200 ± 20 μmol m^?2 s^?1 or low irradiance (LI; 100 ± 20 μmol m^?2 s^?1). During this experiment, leaf pigment content, chlorophyll a fluorescence, gas exchange, stomata morphology, the activity of the Calvin cycle enzymes and saccharides were measured in persistent and new leaves. The results indicated that HI induces a higher photosynthetic performance compared to LI. Therefore, plants acclimatized under HI are likely to survive better after field transfer.     

Wood ontogeny during ex vitro acclimatization in micropropagated hybrid poplar clones

Wood ontogeny patterns were determined during the ex vitro acclimatization period in micropropagated plantlets of hybrid poplar clones T-14 [Populus tremula × (Populus × canescens)] and T-50 [(Populus × canescens) × Populus tremula]. The temporal course of developmental changes in the woody tissue was characterized on a weekly basis starting from the day of transfer to the ex vitro environment until full acclimatization was achieved on day 28. In vitro rooted plantlets had already initiated lignification of secondary xylem cells. The greatest increase in the amount of woody tissue was observed on days 21 and 28. At the end of the acclimatization period, T-14 plantlets contained on average 41.4 % of secondary xylem tissue compared to 30.3 % found in T-50 plantlets. During the course of acclimatization, both clones displayed identical patterns of vessel lumen size distribution from small vessel lumen area to large vessel lumen area. This pattern differs from the characteristic diffuse-porous pattern of approximately evensized vessel lumen area distribution typical of mature wood. At the end of acclimatization, the differences in vessel lumen area and relative conductivity between the clones were negligible. Development of secondary xylem tissue during ex vitro acclimatization promotes the establishment of vigorous regenerants with stems that show increased bending strength and stiffness.     

De novo sequencing and development of EST-SSR for Gevuina avellana (Proteaceae), a nut tree from South America

?Premise of the study: The aim of this study was to develop molecular tools to investigate the genetic structure and diversity of natural populations of Gevuina avellana (Molina, Proteaceae), the Chilean hazelnut. Simple sequence repeats (SSRs) derived from expressed sequence tags (EST-SSRs) were developed, optimized, and characterized. ?Methods and Results: The microsatellite-containing sequences were selected from a cDNA library developed from the nut. The eight marker loci showed two to seven alleles in 60 unrelated trees, from two different natural populations. The observed heterozygosity (H(o)) was 0.44, ranging from 0.07 to 0.92 for different loci. When the multilocus genotype of the eight EST-SSRs was considered, all trees could be differentiated. ?Conclusions: The newly identified EST-SSRs in G. avellana and the multi-pooling strategy involving eight markers will facilitate future studies of clone identification, genetic structure, and diversity.     

Effects of thyroidectomy and submaxillary sialoadenectomy on physiological parameters in the female rat

The effects of interaction of the thyroid function with the submaxillary glands on the female rat, on the body growth, weight evolution of adrenal glands, ovary and parotid glands, puberty onset, estrous cycle, fertility, gestation and offspring size, plasmatic levels of glucose, glucagon, Na+, K+ and total protein have been studied. The effects of sialadenectomy and thyroid function are both independent in all parameters, except in ovary growth, which is depressed by thyroid function when submaxillary glands are removed, and in circulating glucose, since sialadenectomy stabilizes to hypoglycemia which results from thyroidectomy.     

Biochemical and physiological changes produced by Azotobacter chroococcum (INIFAT5 strain) on pineapple in vitro-plantlets during acclimatization

This study highlights some of the effects of the application of Azotobacter chroococcum (INIFAT5 strain) on in vitro-pineapple plantlets during acclimatization. The bacteria were sprayed immediately after transplanting to the ex vitro environment; the plants were then sprayed every 4 week. Subsequently (4 months) the evaluated variables included plantlet fresh and dry weights, leaf and root lengths, and composition of minerals, amino-acids, carbohydrates and proteins. Photosynthesis indicators were also evaluated. Significant effects of the application of Azotobacter over pineapple plantlets during acclimatization were observed in the mineral, amino-acid, carbohydrate and protein levels, as well as, in the photosynthesis indicators. Contrastingly, plant growth parameters showed modest increases caused by the bacteria, although they were statistically significant. Looking into specific minerals, the following significant effects of Azotobacter should be highlighted: increased levels of nitrogen, phosphorous, potassium, magnesium, copper and zinc. Moreover, contents of all amino-acids recorded showed significant increases in their levels in sprayed plantlets. Carbohydrates were also increased in leaves of plantlets bio-fertilized with the bacteria, mainly sucrose and fructose. Chlorophyll b levels were also significantly increased by Azotobacter. The biofertilizer did not modify levels of calcium, iron or manganese.     

Phenolic compounds profiles during ex vitro acclimatization of micropropagated Hypericum polyanthemum.

Accumulation of benzopyrans and total phenolic compounds were assessed in acclimatized field grown plants of Hypericum polyanthemum, an endemic species of southern Brazil, harvested at different developmental stages. The HPLC analysis of bioactive compounds 6-isobutyryl-5,7-dimethoxy-2,2-dimethylbenzopyran (HP1), 7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethyl-benzopyran (HP2) and 5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethyl-benzopyran (HP3) revealed that the three benzopyrans are accumulated both in the vegetative and reproductive parts with maximum contents observed after 18 weeks (in the former) and 20 weeks (in the later) of plant growth (1.92+/-0.085 g % DW and 2.62+/-0.13 g % DW in the vegetative and reproductive parts, respectively). Highest contents of HP1 (1.56+/-0.12 g % DW) and HP2 (0.19+/-0.01 g % DW) were quantified in the green floral buds of the plants, whereas HP3 reached the highest level (1.02+/-0.08 g % DW) in the overblown flowers. The evaluation of total phenolic compounds showed that the vegetative parts accumulated the highest levels of the metabolites (51.93+/-0.67 mg QE (g DW)(-1)) after 16 weeks of plant growth. Considering the reproductive parts, the open flowers accumulated the greatest levels of the bioactive compounds (75.99+/-0.95 mg QE (g DW)(-1)). The results show that H. polyanthemum can be efficiently propagated and acclimatized to produce benzopyrans and other phenolic compounds.     

Effects of blue pulsed light on human physiological functions and subjective evaluation

Background

It has been assumed that light with a higher irradiance of pulsed blue light has a much greater influence than that of light with a lower irradiance of steady blue light, although they have the same multiplication value of irradiance and duration. We examined the non-visual physiological effects of blue pulsed light, and determined whether it is sensed visually as being blue.

Findings

Seven young male volunteers participated in the study. We placed a circular screen (diameter 500 mm) in front of the participants and irradiated it using blue and/or white light-emitting diodes (LEDs), and we used halogen lamps as a standard illuminant. We applied three steady light conditions of white LED (F0), blue LED + white LED (F10), and blue LED (F100), and a blue pulsed light condition of a 100-μs pulse width with a 10% duty ratio (P10). The irradiance of all four conditions at the participant''s eye level was almost the same, at around 12 μW/cm². We measured their pupil diameter, recorded electroencephalogram readings and Kwansei Gakuin Sleepiness Scale score, and collected subjective evaluations. The subjective bluish score under the F100 condition was significantly higher than those under other conditions. Even under the P10 condition with a 10% duty ratio of blue pulsed light and the F10 condition, the participant did not perceive the light as bluish. Pupillary light response under the P10 pulsed light condition was significantly greater than under the F10 condition, even though the two conditions had equal blue light components.

Conclusions

The pupil constricted under the blue pulsed light condition, indicating a non-visual effect of the lighting, even though the participants did not perceive the light as bluish.     

Morphological, physiological and oxidative stress markers during acclimatization and field transfer of micropropagated Tuberaria major plants

Tuberaria major (Willk.) P. Silva and Rozeira is a critically-endangered rock rose species endemic to Portugal. Because the species needs to be preserved, this study evaluated the morphological and physiological traits of micropropagated T. major plants during acclimatization and field transfer. There were no significant differences between wild and micropropagated plants in the field, although the latter underwent significant changes during acclimatization. Leaf pubescence and leaf mass per area increased during acclimatization whereas the chlorophyll content and chlorophyll/carotenoid ratio declined to eventually match those of wild plants. Stomatal conductance (g_s) and transpiration rates (E) also declined substantially during acclimatization, thus preventing uncontrolled wilting. Photosynthetic rate (P_N) was initially negative but increased during the later stages of acclimatization. Maximum quantum yield of PSII (F_v/F_m) remained constant at 0.78–0.85, showing that the plants were healthy and unstressed. PSII quantum efficiency (?_PSII) was initially low but increased during acclimatization along with photosynthetic performance as the energy partitioning in PSII was adjusted. This was balanced by the decline in non-regulated energy dissipation (?_NO) from an initially high value. Electrolyte leakage and malondialdehyde content remained constant at similar levels in both groups of plants, but H₂O₂ levels were higher in the field, perhaps indicating the early induction of antioxidant defense systems. The present study shows that T. major has enough phenotypic plasticity to adapt to changing environments and that the procedure described herein can be used for the restoration and preservation of this species.     

Comparative stability of physiological parameters during sustained anesthesia in rats

Rats were anesthetized with pentobarbital, pentobarbital and atropine, inactin [5-ethyl-5-(1'-methyl-propyl)-2-thiobarbiturate], ether and inactin, or urethane. Cardiovascular and arterial acid-base parameters were monitored over a 3-hour period of anesthesia. Heart rate, arterial pressures, and pH progressively decreased with duration of pentobarbital anesthesia. Changes observed in rats anesthetized with the thiobarbiturate, inactin, were similar although generally less severe. Most subjects treated with the barbiturates were markedly hypercapnic. Urethane anesthesia was characterized by a higher and more stable heart rate and greater pulse pressure. Arterial carbon dioxide and bicarbonate levels in the urethane group were substantially lower at all sampling times than the values obtained in the barbiturate groups.     

Use of gentian violet to differentiate in vitro and ex vitro-formed roots during acclimatization of grapevine

The dye gentian violet was added to culture medium in order to distinguish in vitro and ex vitro-formed roots during acclimatization of micropropagated plantlets. Shoots of the grapevine rootstock Kober 5BB were rooted on media containing the dye (0.3 and 0.15 mg·l^–1) for 3 weeks. The dye coloured the roots. Root length was reduced by the presence of the dye, but root number and shoot growth were not affected. Most in vitro-formed roots continued to grow during acclimatization, and 3 weeks after the transfer to soil the root system was 60% composed of in vitro-formed roots. Our results suggest that in grapevine Kober 5BB, the in vitro-formed roots contribute to plantlet growth at least during acclimatization.     

Effects of waterlogging on growth and some physiological parameters of four Brassica species

Waterlogging tolerance of four Brassica species, Brassica campestris L., B. carinata A. Br., B. juncea (L.) Czern and Coss., and B. napus L. was assessed after 4 weeks growth in greenhouse at two waterlogging treatments, unflooded control soil, and fully waterlogged soil.Shoot fresh and dry biomass, in both mean and relative terms, was highest in B. juncea and lowest in B. napus at waterlogging treatment. B. carinata was as good as B. juncea in mean shoot fresh and dry matter but it had almost same relative shoot fresh matter as that in B. campestris, but was second highest in relative shoot dry weight.Waterlogging treatment caused a marked reduction in chlorophyll content in all four species but the species difference was not evident. However, B. juncea and B. napus had lower relative total chlorophyll than the other species.A marked increase in soluble protein content of B. juncea and a significant increase in total amino acids in B. carinata was observed under waterlogged conditions as compared to the other species.At the waterlogging regime, an increase in iron content in both shoots and roots was observed in all four species. B. juncea accumulated lower amount of iron in both shoots and roots as compared to the other species, whereas B. carinata had also lower iron in the roots. The species did not differ for shoot manganese content but B. carinata had significantly higher manganese in the roots as compared to the other species.     

Ethylene and in vitro rooting of hazelnut (Corylus avellana) cotyledons

Ethylene may be one of the many factors that play a role in rooting. However, in some studies ethylene promoted rooting, while in others it was inhibitory or had no effect. Using cotyledons of hazelnut ( Corylus avellana L. cv. Casina) observations were made of the effect of ethylene precursors on adventitious root formation. l-methionine (Met) or 1-aminocyclopropane-1-carboxylic acid (ACC) added to a standard indole-3-butyric acid (IBA)-kinetin-containing medium did not enhance rooting, while 2-chloroethylphosphonic acid (CEPA) did. The ethylene inhibitor, aminoethoxyvinylglycine (AVG), inhibited root formation, but its effect was reversed by ACC when cotyledonary segments were transferred to rhizogenic medium plus ACC at day 10. Ethylene production by cotyledons cultured on rhizogenic medium or rhizogenic medium plus CEPA was high at the beginning of rooting. Thus, the wound-induced ethylene is a key stimulatory factor in the formation of root primordia. The data support the hypothesis that ethylene plays a positive role in root formation.     

Influence of in vitro growth conditions on photosynthetic competence and survival rate of Rehmannia glutinosa plantlets during acclimatization period

The photosynthetic responses of Rehmannia glutinosa grown under photoautotrophic or heterotrophic conditions in vitro were investigated after transfer to greenhouse conditions. In addition, the changes in carbohydrate content and survival rates of the plantlets were evaluated. During six days after transplantation, the photosynthetic rate declined and photoinhibitory impairments represented by decrease of Fv/Fm and chlorophyll content were observed regardless of environmental conditions in vitro. Excessive transpiration was observed in plantlets grown under heterotrophic conditions during that period. Fructose and glucose content of the plantlets grown under photoautotrophic conditions increased with time and reached almost the same level of field grown plants after day 15. Under heterotrophic conditions, in contrast, the content of these sugars decreased continuously during that period. It is suggested that high survival rate of plantlets grown under photoautotrophic conditions has to be attributed to improvement of photosynthetic competence by imposed high light intensity and CO₂ concentration in vitro. The results strongly suggest that the control of transpiration during early stage after transplantation plays a key role in the acclimatization process, and photoautotrophic conditions could be a solution to solve the problems associated with transplantation stress. This revised version was published online in June 2006 with corrections to the Cover Date.