Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover (T. subterraneum L.) I. Effects of temperature

1966 ◽  
Vol 17 (1) ◽  
pp. 29 ◽  
Author(s):  
RC Rossiter ◽  
AB Beck
Keyword(s):  
Total Concentration ◽  
Subterranean Clover ◽  
Maximum Growth ◽  
Biochanin A ◽  
Ecological Studies ◽  
Leaf Material ◽  
Long Day ◽  
Effects Of Temperature

Two strains of subterranean clover – Yarloop and Mt. Barker – were grown at controlled temperatures ranging from 36/31° to 9/4°C under long-day conditions. Leaf material was analysed for the three isoflavones formononetin, genistein, and biochanin A. In the Mt. Barker strain, the formononetin concentration was low (< 0.2% dry wt.) and varied little with temperature. Otherwise, isoflavone levels generally rose from very low values at 36/31° to a peak at 15/10°, and then decreased again to 9/4°. For both strains the total concentration of the three isoflavones and also the total amount of isoflavones per leaf were highest at 15/10°. This temperature was lower than that at which maximum growth occurred. The data are discussed in relation to evidence on the effects of temperature on the formation of flavonoid (especially anthocyanin) compounds. We conclude that temperature is unlikely to be a major factor in the incidence of "clover disease".

Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover (T. subterraneum L.) VII. Effects of nitrogen supply

1969 ◽  
Vol 20 (6) ◽  
pp. 1043 ◽  
Author(s):  
RC Rossiter
Keyword(s):  
Protein Synthesis ◽  
Nitrogen Deficiency ◽  
Subterranean Clover ◽  
Nitrogen Supply ◽  
The Other ◽  
Biochanin A ◽  
Ecological Studies ◽  
Carbon Substrates ◽  
Low Nitrogen ◽  
Practical Implications

In experiments with young plants of the Dwalganup strain of subterranean clover, nitrogen deficiency was associated with increased concentrations of isoflavones in the expanded leaves and cotyledons. In the first trifoliate leaves the concentration of total isoflavones (formononetin+genistein+ biochanin A) was approximately doubled at low nitrogen supply. Biochanin A was much less affected than the other two isoflavones. The increase in isoflavone contents of nitrogen-deficient leaves was associated with decreased protein synthesis, but not always with increased sugar contents. The supply of carbon substrates for isoflavone synthesis may depend on starch as well as sugar contents. Practical implications of the results are considered briefly.

Free and conjugated isoflavones in the plasma of sheep following ingestion of oestrogenic clover

1967 ◽  
Vol 18 (4) ◽  
pp. 647 ◽  
Author(s):  
DA Shutt ◽  
A Axelsen ◽  
HR Lindner
Keyword(s):  
Plasma Level ◽  
Total Concentration ◽  
Red Clover ◽  
Subterranean Clover ◽  
Inhibitory Effect ◽  
Water Soluble ◽  
Biochanin A ◽  
Uterine Weight ◽  
Sheep Grazing

The plasma of sheep grazing various species of oestrogenic clover contained water-soluble conjugates of daidzein, formononetin, genistein, and biochanin A, chiefly in the form of glucuronides, in concentrations up to 40 µg/100 ml. In sheep pen-fed on red clover or subterranean clover (cv. Dinninup and Yarloop) the total concentration of these four isoflavones 3–5 hr after feeding ranged from 150 to 720 µg/100 ml plasma, of which 1–2% only was present in "free" (i.e. unconjugated) form; by 24 hr the plasma level had fallen to < 5 µg/100 ml plasma. Preconditioning the pen-fed sheep to oestrogenic clover, or adding lucerne to the diet, had no significant effect on the concentration of "free" or conjugated isoflavones in the plasma and had no inhibitory effect on the uterine weight response. Comparison of the composition of circulating isoflavones to that of the clover ingested indicated partial demethylation of formononetin to daidzein and of biochanin A to genistein, and suggested that genistein and biochanin A were degraded more rapidly than formononetin or daidzein in the sheep. Equol, a metabolite previously isolated from the urine of sheep treated with formononetin, was present in the plasma at a concentration of 50–170 µg/100 ml 24 hr after feeding.

Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover (T. subterraneum L.). IX.* Effects of sulphur supply

1972 ◽  
Vol 23 (3) ◽  
pp. 411 ◽  
Author(s):  
RC Rossiter ◽  
NJ Barrow
Keyword(s):  
Subterranean Clover ◽  
The Other ◽  
Biochanin A ◽  
Ecological Studies ◽  
Sulphur Deficiency ◽  
Severe Deficiency ◽  
Practical Implications

The results of field and glasshouse experiments showed that sulphur deficiency increased isoflavone concentrations in clover leaves. Severe deficiency almost doubled the concentration of total isoflavones (formononetin + genistein f biochanin A). Usually formononetin was affected as much as, or more than, either of the other two isoflavones. Four clover strains—Dwalganup, Geraldton, Daliak, and Yarloop—which differed widely in their isoflavone concentrations did not differ significantly in their proportionate increases in isoflavone concentrations due to severe sulphur deficiency. Practical implications of the results are considered briefly. __________________ *Part VIII, Aust. J. Agric. Res., 21: 593 (1970).

Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover (T. subterraneum L.) V. Ontogenetic change

1967 ◽  
Vol 18 (4) ◽  
pp. 561 ◽  
Author(s):  
RC Rossiter ◽  
AB Beck
Keyword(s):  
Age Differences ◽  
Cell Expansion ◽  
Leaf Age ◽  
Subterranean Clover ◽  
Biochanin A ◽  
Ontogenetic Change ◽  
Ecological Studies ◽  
Expansion Stage ◽  
Low Levels ◽  
The Individual

On plants of the same age, differences between leaves in the concentrations of the oestrogenic isoflavones daidzein (D), formononetin (F), genistein (G), and biochanin A (BA) were largely due to differences in leaf age. Concentrations of F, G, and BA declined during unfolding and development of the individual leaf. The maximum amounts per leaf of F, G, and BA were attained at the completion of the cell expansion stage. The appearance of D was associated with leaf senescence. The concentrations of F, G, and BA in expanded leaves usually declined during plant growth. An exception was F in the Yarloop strain. Relatively low levels of isoflavones were found in the stem + petiole fraction and in the roots, and intermediate levels in flowers. The relevance of these results to animal bioassays for oestrogenic activity is discussed.

Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover, (T. subterraneum L.) VIII. Phosphate supply in relation to temperature and to leaf development

1970 ◽  
Vol 21 (4) ◽  
pp. 593 ◽  
Author(s):  
RC Rossiter
Keyword(s):  
Leaf Growth ◽  
Subterranean Clover ◽  
Relative Difference ◽  
Biochanin A ◽  
Leaf Cell ◽  
Ecological Studies ◽  
Leaf Emergence ◽  
Carbon Substrates ◽  
Phosphate Supply ◽  
High Phosphate

In recently expanded first trifoliate leaves of the Dwalganup strain of subterranean clover, the relative difference for concentrations of formononetin at low and high phosphate supply levels was about the same at 12.5, 22.5, and 32.5�C. However, absolute differences were much less at the high temperature, where concentrations were also low. The concentrations of the other isoflavones, genistein and biochanin A, were much less affected by phosphate supply than was formononetin. Effects of phosphate on isoflavone concentrations were already evident at leaf emergence; and in phosphate-deficient leaves, concentrations of isoflavones - especially formononetin - increased during the later stages of leaf growth. Isoflavone production per leaf cell seems to be dependent on the supply of carbon substrates in the form of sugars and starch.

Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover (T. subterraneum L.). II. Effects of phosphate supply

1966 ◽  
Vol 17 (4) ◽  
pp. 447 ◽  
Author(s):  
RC Rossiter ◽  
AB Beck
Keyword(s):  
Subterranean Clover ◽  
Dry Weight ◽  
Biochanin A ◽  
Phosphate Deficiency ◽  
Ecological Studies ◽  
Carbon Substrates ◽  
Phosphate Supply ◽  
Total Dry Weight

Two experiments with the Mt. Barker strain of subterranean clover and one with the Dwalganup strain were conducted. In each experiment, increase in phosphate supply led to increases in total dry weight production. As phosphate deficiency became more acute in the Dwalganup strain, the leaf concentrations of two isoflavones, formononetin and genistein, increased as much as twofold; a third isoflavone, biochanin A, showed little change. In the Mt. Barker strain the concentrations of genistein and biochanin A increased about twofold with increasing severity of phosphate deficiency, while those of formononetin increased at least fourfold. It is suggested that isoflavone formation in clover leaves increases under phosphate deficiency, and that this is associated with increased carbon substrates in the leaf cells. The relations between isoflavone levels and oestrogenic potency are discussed. Phosphate deficiency may be indirectly related to oestrogenic potency through its influence on isoflavone levels.

The effects of grazing on the phosphorus requirement of an annual pasture

1971 ◽  
Vol 22 (1) ◽  
pp. 81 ◽  
Author(s):  
PG Ozanne ◽  
KMW Howes
Keyword(s):  
Subterranean Clover ◽  
Growing Season ◽  
Maximum Growth ◽  
Grazing Pressure ◽  
Light Interception ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Phosphorus Requirement ◽  
Root Size

The applied phosphorus requirement of a pasture sown to subterranean clover was measured with and without grazing. Under moderate grazing pressure, in the year of establishment, the pasture required about 50 % more phosphorus than when ungrazed. In the following season, at a higher stocking rate, the grazed areas needed twice as much phosphorus as the ungrazed to make 90% of their maximum growth. In both years this difference in requirement between stocked and unstocked treatments was present throughout the growing season. Increased phosphorus requirement under grazing is associated with the need for greater uptake of phosphorus under conditions where redistribution of absorbed phosphorus within the plant is prevented by defoliation. It does not appear to be due to effects of defoliation on root size. Nor does it depend on differential light interception or on changes in botanical composition.

Physiological and ecological studies on the oestrogenic isoflavones in subterranean clover (T. subterraneum L.) III. Effects of light

1967 ◽  
Vol 18 (1) ◽  
pp. 23 ◽  
Author(s):  
RC Rossiter ◽  
AB Beck
Keyword(s):  
Light Intensity ◽  
Subterranean Clover ◽  
Substantial Effect ◽  
The Other ◽  
Light Environment ◽  
Natural Light ◽  
Ecological Studies ◽  
Other Hand ◽  
Isoflavone Content ◽  
Per Se

Isoflavone levels in subterranean clover leaves were higher in 13 hr days of natural daylight than in 6 hr days, but length of photoperiod per se had no substantial effect on these levels. In the field, reduction of light intensity (by shading) to 40% daylight caused no decline in isoflavone levels compared with full daylight; even at 24% daylight the reduction in levels was ill defined. On the other hand, in young seedlings there was a marked fall in isoflavone content, especially in the unifoliate leaf, as light intensity fell from 950 to 320 f.c. However, appreciable isoflavone formation was found in dark-grown clover seedlings. Possible light reactions connected with the promotion of isoflavone synthesis are discussed. Changes in isoflavone levels resulting from variation in the natural light environment are unlikely to be sufficient to affect "clover disease".

Adaptation by sheep to isoflavones in clover

1969 ◽  
Vol 9 (41) ◽  
pp. 569 ◽  
Author(s):  
FHW Morley ◽  
D Bennett ◽  
A Axelsen
Keyword(s):  
Subterranean Clover ◽  
Biochanin A ◽  
Uterine Weight ◽  
Pre Treatment ◽  
High Concentrations

Vaginal mucus scores and uterine weights of ovariectomized ewes that grazed subterranean clover for 13 days prior to tests were similar to those from ewes fed non-oestrogenic rations during this pre-treatment, if the leaves of test clovers contained high concentrations of formononetin (F) (Yarloop and Dinninup). No responses were obtained from subterranean clovers low in F, but high in genistein (G) or biochanin A (BA) (Clare and Bacchus Marsh) except for a group which was fed a non-oestrogenic diet during pre-treatment, and which gave a positive mucus test, but not a stgnificant uterine weight response. These results indicate that ewes can become non-responsive to G and BA, but not to F, and offer an explanation for some inconsistencies among bioassays of subterranean clovers. The task of selection and breeding of subterranean clover seems to be simplified since G and BA are unlikely to be harmful.

The effects of temperature and photoperiod on the induction of diapause in eggs of the Australian plague locust, Chortoicetes terminifera (Walker) (Orthoptera: Acrididae)

1980 ◽  
Vol 70 (4) ◽  
pp. 635-647 ◽  
Author(s):  
K. G. Wardhaugh
Keyword(s):  
Developmental Stages ◽  
Natural Conditions ◽  
Nymphal Stage ◽  
Light Regimes ◽  
Egg Diapause ◽  
Long Day ◽  
First Instar ◽  
Inductive Constant ◽  
Effects Of Temperature ◽  
Australian Plague Locust

AbstractPhotoperiod was shown to be the principal factor regulating the induction of a facultative egg-diapause in Chortoicetes terminifera(Wlk.). All developmental stages from first-instar nymphs to immature adults were sensitive to photoperiod. At constant photophases, the insect exhibited a short-day—long-day response, with the upper and lower critical photo-periods for induction approximating to LD 15·5: 8·5 and 11:13, respectively. These correspond to the range of photoperiods experienced by the insect under natural conditions. The maximum inductive response occurred at about the mid-point of this range, i.e. LD 13·5: 10·5. In experiments in which insects experienced a change in photophase at the end of the nymphal stage, the incidence of diapause varied with the direction of change (long to short or short to long) and indicated that diapause induction was prevented by an increase in photophase but enhanced when the photophase was reduced. The size of the inductive response associated with a decrease in photophase appeared to depend less on the size of the decrease than on its position within the inductive range, such that the maximum effects were observed when the sequence of light regimes were close to or spanned the most inductive constant photophase. Temperature was also important in determining the induction of diapause. In the upper portion of the inductive range (15·5 to 12·5 h light), insects subjected to high temperatures or to an increase in temperature during development showed a lower incidence of diapause than those subjected to low temperatures or to a decrease in temperature. In the lower portion of the inductive range, the effects of temperature were reversed, with high temperature or an increase in temperature being more inductive than low temperature or a decrease in temperature.

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