scholarly journals Effect of auxin on xylem tracheids differentiation in decapitated stems of Pinus silvestris L. and its interaction with some vitamins and growth regulators

2015 ◽  
Vol 43 (1) ◽  
pp. 129-148 ◽  
Author(s):  
T. J. Wodzicki ◽  
S. Zajączkowski
Keyword(s):  
Vitamin A ◽  
Cell Metabolism ◽  
Choline Chloride ◽  
Late Summer ◽  
Cambial Activity ◽  
Xylem Differentiation ◽  
Pinus Silvestris ◽  
Quantitative Expression ◽  
Secondary Wall Formation ◽  
Tracheid Differentiation

The effects of several vitamins and substances known as important agents in regulation of cell metabolism upon secondary xylem differentiation were studied in interaction with auxin (IAA) as applied in lanoline to decapitated stems of 5-year-old <i>Pinus silvestris</i> trees in early and late-summer. Tested substances were: gibberellic acid, kinetin, nicotinic acid, thiamine, pyridoxine, calcium panthotenate, choline chloride, riboflavin, inositol, ascorbic acid, vitamin, A (alcohol), vitamin A (ester), saponin. None of the effects of these substances appeared significant enough to indicate the involvement in the seasonal variation of the response of cambium or differentiating tracheids to auxin. However, several effects, especially those of inositol, vitamin A and pyridoxine upon cambial xylem production and further stages of tracheid differentiation were observed. Auxin (IAA) affected cambial activity and subsequent differentiation of tracheids during the earliest stages of cell ontogenesis. At these stages auxin treatment induced quantitative expression of the developmental processes involving radial growth and secondary wall formation by tracheids. In this respect, auxin did not affect cells advanced in differentiation, however, it proved to be an essential factor in the completion of the full cycle of tracheid ontogenesis.

scholarly journals The possible relation between cytokinins and secondary xylem formation in Pinus silvestris. I. Seasonal correlations

2015 ◽  
Vol 48 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Dorota B. Kubowicz
Keyword(s):  
Annual Ring ◽  
Secondary Xylem ◽  
Late Summer ◽  
Cambial Activity ◽  
Cytokinin Activity ◽  
Endogenous Cytokinin ◽  
Pinus Silvestris ◽  
Xylem Formation ◽  
Summer Maximum ◽  
Spring Maximum

The Seasonal dynamics of changes in the endogenous cytokinin level was investigated in the tissue of the stem cambial region, The results of the soybean test and Amaranthus test show that marked variations occur. in the course of the year in cytokinin activity in five fractions obtained from tissue of the cambial region. These variations characterized by a spring maximum and late-summer maximum may be correlated in time with changes in cambial activity and the course of annual ring differentiation in the pine stem during the vegetation season.

352. Variations in the carotene and vitamin A contents of certain New Zealand butterfats

1947 ◽  
Vol 15 (1-2) ◽  
pp. 80-88 ◽  
Author(s):  
C. R. Barnicoat
Keyword(s):  
New Zealand ◽  
Vitamin A ◽  
Normal Values ◽  
Late Summer ◽  
Dairy Farms ◽  
Late Winter ◽  
Total Vitamin ◽  
The North ◽  
The Difference ◽  
Very High

1. Chemical estimations of carotene and vitamin A in New Zealand butters from two of the principal butter-making districts of the North Island during the seasons 1935–6 show that the total vitamin A potency was fairly high.2. There were seasonal variations apparently due to nutritional rather than physiological causes. The minimum values (33–37 i.u./g. butterfat) for total vitamin A were found in late summer (February) at the time when the pasture normally tends to dry up, while the peak values (42–53 i.u./g. butterfat) occurred in late winter and spring (July-October). The variations in vitamin A potency with season were in the opposite direction to the variations recorded in the literature for Europe and America. The difference is no doubt due to the practice of stall-feeding in these countries in contrast with the all-the-year-round grazing commonly practised on dairy farms in New Zealand. The spring flush of grass is also later in the season in Europe than in New Zealand.3. The more deeply-coloured Jersey butterfat was only slightly richer in total vitamin A potency than Friesian butterfat.4. Contents of carotene and vitamin A in the fat of colostrum were very high, but reached normal values within 4 or 5 days after parturition.

The rumenitis and liver abscess complex and vitamin A status in beef cattle

1970 ◽  
Vol 12 (2) ◽  
pp. 291-298
Author(s):  
A. C. Rowland
Keyword(s):  
Vitamin A ◽  
Late Summer ◽  
Early Spring ◽  
Agglutination Test ◽  
Late Winter ◽  
Liver Lesions ◽  
Seasonal Incidence ◽  
Vitamin A Status ◽  
The Mean ◽  
Intensively Managed

SUMMARYThe seasonal incidence of rumen and liver lesions is recorded in traditional and in intensively managed cattle, together with the vitamin A status of the two groups. Rumen lesions were observed to reach a peak in the late winter and early spring in traditional cattle, at which time the liver vitamin A levels fell to the lowest point; liver lesions reached a peak in the late summer. No specific trend was observable in rumen and liver lesions in the barley beef group. The mean levels of vitamin A were approximately one-third of those shown by the traditionally managed animals.It did not prove possible using the agglutination test to identify the sera of animals showing active hepatic necrobacillosis at the time of slaughter.

502. The vitamin A potency of New Zealand butter

1953 ◽  
Vol 20 (1) ◽  
pp. 76-100 ◽  
Author(s):  
A. K. R. McDowell ◽  
F. H. McDowall
Keyword(s):  
New Zealand ◽  
Vitamin A ◽  
Northern Hemisphere ◽  
Seasonal Variations ◽  
Late Summer ◽  
Early Spring ◽  
Seasonal Trends ◽  
Late Autumn ◽  
Grazing Period ◽  
Summer Grazing

Results of a survey of the carotene and vitamin A contents, and of the vitamin A potency, of New Zealand butterfat and butter, are presented. The butter samples were drawn from twenty representative commercial factories at fortnightly intervals over three successive years (1946–8). The survey covers the analysis of 1517 samples of fresh butter and 670 samples of stored butter.There were uniform and regularly recurring seasonal variations in both carotene and vitamin A contents of butterfats from all North Island districts. Maximum values were found in the late-autumn/winter/early-spring, and minimum values in the late-summer/early-autumn butterfats. The seasonal trends were thus distinctly different from those which have been reported for northern hemisphere butterfats, for which the maximum values are commonly found during the summer grazing period.The seasonal variations in carotene and vitamin A contents of South Island butterfat were less marked and less consistent than those in the corresponding values for North Island butterfat.

scholarly journals Proteolytic activity in the stem cambial region of Pinus sylvestris L. - A contribution to the specific differentiation of secondary xylem and phloem

2014 ◽  
Vol 63 (3-4) ◽  
pp. 247-253 ◽  
Author(s):  
Krzysztof J. Rakowski ◽  
Tomasz J. Wodzicki
Keyword(s):  
Pinus Sylvestris ◽  
Protease Inhibitor ◽  
Electrophoretic Mobility ◽  
Proteolytic Activity ◽  
Secondary Xylem ◽  
Cambial Activity ◽  
The Other ◽  
Xylem Differentiation ◽  
Phloem Tissue ◽  
Ph Optimum

Proteolytic activity was studied in the differentiating xylem and phloem of Scots pine (<i>Pinus sylvestris</i> L.) to determine the specificity of xylem and phloem differentiation. The activity of autolytic proteases was demonstrated in the differentiating xylem during spring, summer and autumn and it was not detectable during winter. It was initiated with the onset of cambial activity in spring and unchanged during subsequent stages of xylem differentiation. The same proteolytic activity was not detectable in the extract of fresh phloem tissue. It could be detected in phloem after removal of the inhibitor found in the extract. The same pH optimum was determined for proteases extracted from xylem and phloem. However, their identity remains uncertain because of different electrophoretic mobility. On the other hand the presence of protease inhibitor in phloem tissue can be an important factor im determining the specificity of xylem an phloem differentiation.

scholarly journals Seasonal variation of auxin in stem cambial region of Pinus sihestris L.

2015 ◽  
Vol 47 (3) ◽  
pp. 225-231 ◽  
Author(s):  
Tomasz J. Wodzicki
Keyword(s):  
Seasonal Variation ◽  
Cambial Activity ◽  
Critical Discussion ◽  
Pinus Silvestris ◽  
Auxin Regulation ◽  
Concentration Changes

Investigation of auxin from the stem cambial region of adult <i>Pinus silvestris</i> trees by diffusion to agar, and by extraction revealed both seasonal variation and gradients along the stem. Variation in dynamics of auxin efflux and the effect of the size of tissue blocks are used as arguments in the critical discussion of the concept of auxin regulation of cambial activity by way of simple seasonal concentration changes.

scholarly journals Seasonal changes in plasma retinol-binding holoprotein concentration in japanese quail (Conturnix coturnix japonica)

1980 ◽  
Vol 43 (2) ◽  
pp. 357-366 ◽  
Author(s):  
J. Glover ◽  
D. J. Heaf ◽  
Suzanne Large
Keyword(s):  
Vitamin A ◽  
Japanese Quail ◽  
Seasonal Changes ◽  
Late Summer ◽  
Hormonal Control ◽  
Egg Laying ◽  
Coturnix Japonica ◽  
Mean Values ◽  
Natural Lighting ◽  
Plasma Retinol

1. Seasonal changes in retinol-binding holoprotein (holoRBP) concentration in plasma of group of male and female Japanese quail (Coturnix coturnix japonica) were examined over 18 months.2. In Expts 1 and 2 the birds were maintained under natural lighting conditions and in Expt 3 under artificial-light photoperiods corresponding to the changing daylength at 56° N latitude. All groups were at 18–20° and received Superlayers' (Rank Hovis McDougall) pellet diet.3. The mean plasma holoRBP concentration in all groups changed in an annual cycle with minimal values in September–October and maximal values in February–April, when daylength or light photoperiod increased to more than 10 h.4. The group mean values in the female cycle change 2- to 3-fold from 50–100 μg/ml in late summer to 220–280 μg/ml in the spring, whereas in the male the range is only 1.3–1.5 times, from 140–170 to 180–250 μg/ml.5. In the female the rate of egg laying was maximal in April–May and lowest in November–December.6. The spring increase in plasma holoRBP reflects the increased vitamin A requirement of birds for reproduction and it is presumably under hormonal control. The wider amplitude in the female cycle compared with the male probably arises from the additional demand for the transfer of vitamin A into the eggs and hence the need for a higher initial secretion rate from the female liver to meet it.

scholarly journals Apical control of xylem formation in the pine stem. II. Responses of differentiating tracheids

2014 ◽  
Vol 51 (2) ◽  
pp. 203-214 ◽  
Author(s):  
Jarosław Porandowski ◽  
Krzysztof Rakowski ◽  
Tomasz J. Wodzicki
Keyword(s):  
Radial Growth ◽  
Inductive Effect ◽  
Secondary Xylem ◽  
Regulatory System ◽  
Continuous Control ◽  
Pinus Silvestris ◽  
Daily Rate ◽  
Xylem Formation ◽  
Tracheid Differentiation ◽  
Cell Wall Deposition

The effect of auxin supplied to the main stem of 5-year-old <em>Pinus silvestris</em> trees during various periods after decapitation upon differentiation of the secondary xylem tracheids was investigated. The results revealed the complexity of auxin involvement in the regulatory system of tracheid differentiation of secondary xylem. It is manifested both as the inductive effect to which the cells respond in the meristematic phase and in the continuous control during the consecutive stages of radial growth and maturation. A lack of auxin during the meristematic phase resulted in smaller cell diameters and reduced the daily rate of cell wall deposition even though these cells progressively grew and matured in the presence of auxin. The intensity of these two processes increased and the cells deposited thicker walls when auxin was supplied during all stages of tracheid differentiation even though the period of maturation decreased. Under these conditions tracheids of compression wood type differentiated. Continuous availability of auxin causes earlier termination of tracheid maturation while lack of auxin results in a delay of autolysis of protoplasts. In this case auxin probably functions in a system specifying information concerning the position of the cells in respect to the cambial layer.

WALL STRUCTURE OF TERMINAL LATEWOOD TRACHEIDS OF HEALTHY AND DECLINING SILVER FIR TREES IN THE DINARIC REGION, SLOVENIA

IAWA Journal ◽  
2003 ◽  
Vol 24 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Uwe Schmitt ◽  
Claudia Grünwald ◽  
Jožica Gričar ◽  
Gerald Koch ◽  
Katarina Čufar
Keyword(s):  
Middle Lamella ◽  
Abies Alba ◽  
Cambial Activity ◽  
Wall Structure ◽  
Silver Fir ◽  
Compound Middle Lamella ◽  
Breast Height ◽  
Transmission Electron ◽  
Secondary Wall Formation ◽  
Lignin Deposition

Fir trees (Abies alba Mill.) in a permanently monitored forest in the Dinaric region in Slovenia respond to crown damages by distinctly reducing their ring widths. According to transmission electron microscopy (TEM) and UV-microspectrophotometry (UMSP) of cambium-adjacent latewood tracheids of affected trees, the secondary wall formation and lignification were completed by the middle of October. In samples taken at the same date from healthy looking silver firs, the S3 and the warty layer were not yet present in cambium-adjacent latewood tracheids. Additionally, their inner S2 showed lower lignin deposition, whereas the compound middle lamella, S1 and outer S2 were distinctly lignified as revealed by TEM and UMSP. It is assumed that these youngest tracheids of healthy trees will later undergo lignification or remain less lignified. From these observations we conclude that the cambial activity at breast height ends later in healthy silver fir trees as compared to declining trees.

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