Calcium stimulation of phosphate absorption by annual legumes

1970 ◽  
Vol 21 (4) ◽  
pp. 601 ◽  
Author(s):  
AD Robson ◽  
DG Edwards ◽  
JF Loneragan

At calcium and phosphate concentrations within ranges commonly encountered in soil solutions, increasing calcium concentration in flowing culture solutions markedly increased phosphate absorption by several annual legumes. Calcium increased phosphate uptake relatively more at low than at high phosphate concentration. The effect of calcium was greater for two Medicago species than for two cultivars of Trifolium subterraneum and is suggested as at least a partial explanation for the greater sensitivity of Medicago to soil acidity and its greater tolerance to soil alkalinity than Trifolium subterraneum. Pretreatment at different calcium levels had no effect on phosphate absorption, while transfer to solutions of different calcium levels caused an immediate response in phosphate uptake. These results indicate that calcium had a direct effect on phosphate absorption, rather than an indirect effect through root morphology or anatomy. It is suggested that calcium increased phosphate absorption by screening electronegative charges on the roots, thus increasing the accessibility of absorption sites to phosphate.

1986 ◽  
Vol 26 (1) ◽  
pp. 59 ◽  
Author(s):  
MDA Bolland ◽  
WJ Collins

On sandy soil near Esperance, W.A., prevention of burr burial compared with covering developing burrs with sand drastically reduced the seed production of three subspp. of Trifolium subterraneum (brachycalycinum, subterraneum and yanninicum) and of T. israeliticum by reducing burr production and seed weight. However, T. globosum produced similar amounts of seed from unburied and buried burrs. On sandy soil at Shenton Park, Perth, W.A., prevention of burr burial also reduced seed production of T. subterraneum subspp. brachycalycinum and subterraneum, this being due to fewer burrs, fewer seeds per burr and lighter seed. For subsp. brachycalycinum, seed yields were two to five times greater from burrs which developed within loose gravel than from those developed over sand (in which fewer burrs were able to bury) as a result of increased production of burrs, more seeds per burr and heavier seed. However, for subsp. subterraneum seed yields were similar from burrs whether developed over gravel or sand.


2011 ◽  
Vol 214 (16) ◽  
pp. 2749-2754 ◽  
Author(s):  
C. Godinot ◽  
R. Grover ◽  
D. Allemand ◽  
C. Ferrier-Pages

1964 ◽  
Vol 15 (1) ◽  
pp. 61 ◽  
Author(s):  
RC Rossiter

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.


2010 ◽  
Vol 61 (6) ◽  
pp. 435 ◽  
Author(s):  
B. S. Dear ◽  
M. B. Peoples ◽  
R. C. Hayes ◽  
A. D. Swan ◽  
K. Y. Chan ◽  
...  

Changes in pasture yield and botanical composition due to gypsum application were examined on Vertosols at two locations of differing soil sodicity, Grogan and Morangarell, in southern New South Wales. Two pasture treatments were examined. One was an annual pasture comprised of 3 annual legumes (2 subterranean clover Trifolium subterraneum L. cultivars, Clare and Riverina, and balansa clover T. michelianum Savi cv. Paradana), while the second treatment consisted of lucerne (Medicago sativa L.) cv. Aquarius sown in a mixture with the same annual legumes. Gypsum had no effect on the establishment or persistence of lucerne at either site. Gypsum increased the number of subterranean clover seedlings present in autumn in annual swards at the more sodic Grogan site in each of the 4 years, but provided no difference when the clover was in a mixture with lucerne. Annual legume seed yields in annual-only swards increased with gypsum by up to 58% at Grogan and 38% at Morangarell. Seed yields of both cultivars of subterranean clover declined as a proportion of the total annual legume seed bank when lucerne was included in the mixture, in contrast to balansa clover (at Grogan) and the naturalised annual legumes, burr medic (M. polymorpha L.) and woolly clover (T. tomentosum L.), which all increased in relative seed yield in the presence of lucerne. Total pasture production at the Grogan site increased with gypsum by up to 15% per annum in annual swards and 36% in lucerne swards depending on the season. Yield responses to gypsum by the lucerne component were observed in 10 of the 13 seasonal yield measurements taken at Grogan. However, total pasture yield and seasonal yields were unaffected by both gypsum and pasture type at the less sodic Morangarell site. It was concluded that sowing a diverse mixture of annual legumes or polycultures was conducive to maintaining productive pastures on these spatially variable soils. Lucerne dried the soil profile (0.15–1.15 m) more than annual pastures at both sites. The combination of gypsum and lucerne enhanced water extraction at depth (0.6–1.15 m) at the Grogan site increasing the size of the dry soil buffer whereas gypsum increased soil water at depth (>0.6 m) under annual swards.


1976 ◽  
Vol 16 (82) ◽  
pp. 739 ◽  
Author(s):  
BJ Scott ◽  
H Brownlee

Dry matter production and seed yields of a range of annual legumes grown in ungrazed swards were measured between 1966 and 1971 on seven sites in the low rainfall wheatbelt of central western New South Wales. Jemalong and Hannaford barrel medics (Medicago truncatula) were the highest yielding medic cultivars tested. Jemalong medic was slightly superior to Hannaford in dry matter production but seed yields were equal. The short season subterranean clovers (Trifolium subterraneum), Dwalganup and Geraldton, yielded much less dry matter and seed than the medics in most experiments. Although the mid-season subterranean clovers, Woogenellup and Clare, persisted for the duration of our experiments, their production was not as consistent as that of the medics, and plant densities decreased. The rose clovers (T. hirtum), Sirint and Kondinin, the cupped clovers (T. cherleri), Beenong and Yamina, and Snail (M. scutellata) and Paragosa (M. rugosa) medics did not produce satisfactory swards.


Author(s):  
D.P. Monks ◽  
D.J. Moot ◽  
M.C. Smith ◽  
R.J. Lucas

'Bolta' and 'Frontier' balansa clover seedlings were counted through two autumns following a large seed set in November 2006, from monocultures sown in a dryland environment in Canterbury. Following rain on 5 January 2007, 65% of 'Bolta' seed and 54% of 'Frontier' seed emerged. 'Bolta' and 'Frontier' balansa clover seedlings were counted through two autumns following a large seed set in November 2006, from monocultures sown in a dryland environment in Canterbury. Following rain on 5 January 2007, 65% of 'Bolta' seed and 54% of 'Frontier' seed emerged. Keywords: annual legumes, balansa clover, Dactylis glomerata, false break, seed bank, spring closing date, Trifolium michelianum, Trifolium subterraneum.


1980 ◽  
Vol 239 (4) ◽  
pp. F352-F359 ◽  
Author(s):  
Paula Q. Barrett ◽  
Joseph M. Gertner ◽  
Howard Rasmussen

Dietary phosphate manipulation results in stable adaptive changes in the transport functions of microvillus membrane vesicles isolated from pig renal cortex. When assayed under sodium gradient conditions, phosphate uptake is enhanced 200–400% in vesicles prepared from animals maintained on a low-phosphate diet (0.22%) compared to high-phosphate diet controls (0.82%). When transport is assayed in sodium preequilibrated vesicles, a 100% enhancement of phosphate uptake is demonstrable. Stimulation of phosphate uptake into low-phosphate diet vesicles after the imposition of a sodium chloride gradient is equivalent if uptake is measured at pH 6.0 or 8.0 and can be kinetically characterized as resulting from a Vmax alteration in the phosphate transport system. Microvillus membrane vesicle phosphate transport is maximally stimulated after only 2 days of dietary deprivation. Although a longer period (1 and 2 wk) of phosphate restriction does not further stimulate phosphate transport, it does result in an inhibition of other sodium gradient-dependent transport systems (glucose, alanine). phosphate transport; phosphate restriction; glucose transport; brush-border vesicles Submitted on October 22, 1979 Accepted on April 25, 1980


Genetics ◽  
2001 ◽  
Vol 159 (4) ◽  
pp. 1491-1499 ◽  
Author(s):  
Dennis D Wykoff ◽  
Erin K O'Shea

Abstract Cellular metabolism depends on the appropriate concentration of intracellular inorganic phosphate; however, little is known about how phosphate concentrations are sensed. The similarity of Pho84p, a high-affinity phosphate transporter in Saccharomyces cerevisiae, to the glucose sensors Snf3p and Rgt2p has led to the hypothesis that Pho84p is an inorganic phosphate sensor. Furthermore, pho84Δ strains have defects in phosphate signaling; they constitutively express PHO5, a phosphate starvation-inducible gene. We began these studies to determine the role of phosphate transporters in signaling phosphate starvation. Previous experiments demonstrated a defect in phosphate uptake in phosphate-starved pho84Δ cells; however, the pho84Δ strain expresses PHO5 constitutively when grown in phosphate-replete media. We determined that pho84Δ cells have a significant defect in phosphate uptake even when grown in high phosphate media. Overexpression of unrelated phosphate transporters or a glycerophosphoinositol transporter in the pho84Δ strain suppresses the PHO5 constitutive phenotype. These data suggest that PHO84 is not required for sensing phosphate. We further characterized putative phosphate transporters, identifying two new phosphate transporters, PHO90 and PHO91. A synthetic lethal phenotype was observed when five phosphate transporters were inactivated, and the contribution of each transporter to uptake in high phosphate conditions was determined. Finally, a PHO84-dependent compensation response was identified; the abundance of Pho84p at the plasma membrane increases in cells that are defective in other phosphate transporters.


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