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.

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.

The effect of phosphate supply on the growth and botanical composition of annual type pasture

1964 ◽  
Vol 15 (1) ◽  
pp. 61 ◽  
Author(s):  
RC Rossiter
Keyword(s):  
Field Experiments ◽  
Total Yield ◽  
Indirect Evidence ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Residual Effects ◽  
Phosphate Deficiency ◽  
Phosphate Supply ◽  
High Phosphate

The results of two long-term field experiments and two 1-year experiments are reported. In three of these, severe phosphate deficiency was present initially. At high phosphate supply, the annual total yield was not significantly related to age of pasture over periods of 10–13 years. At intermediate and low supply, yields relative to high phosphate supply increased significantly with time; these increases are believed to demonstrate residual effects of phosphate. Indirect evidence for nitrogen accretion from clover under severely phosphate-deficient conditions is presented. Sward components—in the long term—responded differentially to phosphate supply. With very low phosphate, erodium (Erodium botrys (Cav.) Bertol.) and flatweed (Hypochoeris glabra L.) were dominant; whereas with high phosphate, cape-weed (Cryptostemma calendula (L.) Druce) and ripgut brome grass (Bromus rigidus Roth)—or else barley grass (Hordeum leporinum Link)—were dominant. Subterranean clover (Trifolium subterraneum L.), though present under these extremes, was relatively more plentiful at intermediate levels of supply. However, at "steady state" conditions, the range in clover content was fairly narrow (from c. 20 to 40%). The significance of these findings to a sheep infertility problem ("clover disease") of subterranean clover-dominant pastures is discussed.

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.) 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.) 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.) 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.

Patterns of growth and nutrient accumulation in expanding leaves of Eucalyptus regnans (Myrtaceae)

2008 ◽  
Vol 56 (1) ◽  
pp. 44 ◽  
Author(s):  
Jacqueline R. England ◽  
Peter M. Attiwill
Keyword(s):  
Leaf Area ◽  
Leaf Growth ◽  
Leaf Age ◽  
Dry Mass ◽  
Nutrient Concentrations ◽  
Nutrient Accumulation ◽  
Leaf Ontogeny ◽  
Clear Trend ◽  
Eucalyptus Regnans ◽  
Leaf Emergence

Patterns of leaf growth and nutrient accumulation were investigated in relation to leaf ontogeny in the tree species Eucalyptus regnans F.Muell. Newly emergent leaves were tagged in the field and collected every 14 days for measurement of leaf dimensions and nutrient concentrations over a 113-day period. Patterns of growth in area, length, width and mass of leaves followed sigmoid curves. An exponential rate of growth for all measures was observed up to 56 days after leaf emergence, after which there was little increase. Conversely, specific leaf area (leaf area/leaf mass) decreased from emergence to about Day 56 and then remained relatively constant. Contents of all nutrients (measured on a leaf basis) increased during leaf expansion. Concentrations of N, P and K decreased and Ca concentration increased, but there was no clear trend for Mg concentration with leaf development. In general, the results of the present study verify previously developed ‘idealised curves’ of changes in dry mass and nutrient concentrations with leaf age for eucalypts. Patterns of leaf growth and nutrient accumulation (particularly N) show that leaves had reached full expansion and physiological maturity by ~80–90 days after emergence.

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