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A 37-year-old Polish immigrant presented with unilateral hip pain and difficulty weight-bearing. Plain radiography and magnetic resonance imaging (MRI) revealed a lytic lesion in the acetabulum, with abnormal serum electrophoresis and bone marrow biopsy. The patient was diagnosed with two rare conditions presenting synchronously – Gaucher disease and plasmacytoma. He was treated with enzyme therapy and radiotherapy, but subsequently developed a recurrence of plasmacytoma in the right femur, confirmed with bone marrow biopsy. This was also treated with radiotherapy, followed by a retrograde femoral nail to reduce the risk of pathological fracture. The patient went on to develop multiple lytic lesions in the ribs and vertebra, seen on MRI. Further bone marrow biopsy confirmed dissemination of the plasmacytoma into multiple myeloma, for which he was treated with systemic chemotherapy. In patients presenting with refractory bone or joint pain, haematological and histological investigations should be considered to exclude less common diagnoses.

Abstract: A high‐affinity‐type sulfate transporter (Group 1: ZmST1;1, Accession No. AF355602) has been cloned from maize seedlings by RT‐PCR. Tissue and cell specific localisation of this sulfate transporter has been determined along the developmental gradient of the root and in leaves of different ages. In S‐sufficient conditions there was uniform low expression of ZmST1;1 in the root and very low expression in the leaves. Increased mRNA abundance and sulfate influx capacity indicated that S‐starvation increased ZmST1;1 expression in roots, especially at the top of the root (just behind the seed, the area possessing most laterals and root hairs) compared to the root tip. Similarly a group 2, probable low affinity‐type sulfate transporter, ZmST2;1, and also ATP‐sulfurylase and APS‐reductase but not OAS(thiol)lyase were induced by S‐starvation and showed highest expression in the upper section of the root. S‐starvation increased root/shoot ratio by 20 % and increased root lateral length and abundance in the region closest to the root tip. As the increase in root proliferation was not as great as the increase in mRNA pools, it was clear that there was a higher cellular abundance of the mRNAs for sulfate transporters, ATP‐sulfurylase, and APS‐reductase in response to sulfur starvation. In the leaves, the sulfate transporters, ATP‐sulfurylase and APS‐reductase were induced by S‐starvation with the most mature leaf showing increased mRNA abundance first. In situhybridization indicated that ZmST1;1 was expressed in epidermal and endodermal cell layers throughout the root whilst OAS(thiol)lyase was highly expressed in the root cortex.

Isolated roots of Lycopersicon esculentum Mill., cultured in axenic conditions were starved of sulphate or phosphate, and uptake capacities for the respective oxyanion-transport systems were observed for several days after sulphate or phosphate withdrawal. Sulphate-uptake capacity of the intact roots, measured in a 20-min period, increased from a control level of 100 nmol · g-1 · h-1 to 1100 nmol · g-1 · h-1 in 10 d, and phosphate-uptake capacity increased from 500 to 1400 nmol · g-1 · h-1 over 4 d. Newly synthesised polypeptides of these root cultures were pulse-labelled in vivo for 2 h, by adding [3H]leucine to the culture medium. The tissue was immediately homogenised and soluble and membrane fractions were prepared. A highly purified plasma-membrane fraction was separated from the crude microsomal membrane fraction using an aqueous two-phase partitioning technique. All fractions were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and autoradiography. A 28-kilodalton (kDa) soluble polypeptide, and 36-, 43-, and 47-kDa plasma-membrane polypeptides were observed to have increased labelling after 4 d of sulphate deprivation. Longer periods resulted in additional polypeptides with increased [3H]leucine incorporation. The synthesis of a 25-kDa membrane polypeptide and a 65-kDa soluble polypeptide was increased after 4 d of phosphate deprivation. Two-dimensional electrophoresis afforded greater resolution of the plasmamembrane polypeptides, confirming increased synthesis of the 36-kDa polypeptide and the presence of the 28-kDa polypeptide in the plasma-membrane preparation from sulphate-starved roots. These polypeptides were also observed in protein-stained two-dimensional gels as low-abundant protein components of the plasmamembrane fraction. It is suggested that the 36-kDa polypeptide may be a component of the plasma-membrane sulphate-transport system and that the 25-kDa polypeptide may be a component of a phosphate-transport system.

Wheat (Triticum aestivum cv Chinese Spring) supplied with 0.45 mM SO42- for 14 d with relative growth rates (RGR) of 0.22 to 0.24 d-1 was deprived of S for 7 to 8 d. There was no significant effect on RGR or leaf development (leaf 2 length was constant; leaf 3 expanded for 2-4 d; leaf 4 emerged and elongated throughout the experiment) during the S deprivation. In controls the net assimilation rate (A) closely reflected leaf ontogeny. S deprivation affected A in all leaves, particularly leaf 4, in which A remained at 8 to 10 [mu]mol CO2 m-2 s-1, whereas in controls A rose steadily to >20 [mu]mol CO2 m-2 s-1. In leaf 2, with a fully assembled photosynthetic system, A decreased in S-deprived plants relative to controls only at the end of the experiment. Effects on A were not due to altered stomatal conductance or leaf internal [CO2] ([C]i); decreases in the initial slope of A/[C]i curves indicated an effect of S deprivation on the carboxylase efficiency. Measurement of Rubisco activity and large subunit protein abundance paralleled effects on A and A/[C]i in S-deprived leaves. Negative effects on photosynthesis in S-deprived plants are discussed in relation to mobilization of S reserves, including Rubisco, emphasizing the need for continuous S supply during vegetative growth.

Three plant sulfate transporter cDNAs have been isolated by complementation of a yeast mutant with a cDNA library derived from the tropical forage legume Stylosanthes hamata. Two of these cDNAs, shst1 and shst2, encode high-affinity H+/sulfate cotransporters that mediate the uptake of sulfate by plant roots from low concentrations of sulfate in the soil solution. The third, shst3, represents a different subtype encoding a lower affinity H+/sulfate cotransporter, which may be involved in the internal transport of sulfate between cellular or subcellular compartments within the plant. The steady-state level of mRNA corresponding to both subtypes is subject to regulation by signals that ultimately respond to the external sulfate supply. These cDNAs represent the identification of plant members of a family of related sulfate transporter proteins whose sequences exhibit significant amino acid conservation in filamentous fungi, yeast, plants, and mammals.

Zinc-efficient wheat (Triticum aestivum L. cv. Warigal) has a greater rate of net Zn uptake than the Zn-inefficient cv. Durati (T. turgidum conv. durum (Desf.) MacKey). In both genotypes Zn uptake is partly repressed at sufficient Zn supply. In contrast, after prolonged Zn deficiency, the rates of net Zn uptake increased in Zn-efficient Warigal and decreased in Zn-inefficient Durati. Intact plants of these two genotypes grown at four Zn nutrition regimes were labelled with 35S; the analysis of translation products by SDS-PAGE indicated increased abundance of a 34-kDa polypeptide in the root-cell plasma membrane fraction of Warigal grown under prolonged Zn deficiency only. Soluble (cytosolic) and microsomal (organelle) fractions did not contain 34-kDa polypeptide in any of the eight treatments. Silver-stained PAGE showed that the 34-kDa polypeptide was present in the plasma membrane of Zn-efficient Warigal regardless of Zn nutrition, indicating that de novo biosynthesis of that polypeptide in 18-day-old plants was regulated by Zn deficiency. The pI of the 34-kDa polypeptide was around pH 5.5 as shown by 2-D PAGE. The 34-kDa polypeptide is the first reported root-cell plasma membrane polypeptide specifically induced under Zn deficiency. Since it is accumulated only in the Zn-efficient wheat genotype, the 34-kDa polypeptide may be connected with the capacity of that genotype to sustain prolonged Zn deficiency.