Cuticular permeance in relation to wax and cutin development along the growing barley ( Hordeum vulgare ) leaf.

The developing leaf three of barley provides an excellent model system for the direct determination of relationships between amounts of waxes and cutin and cuticular permeance. Permeance of the cuticle was assessed via the time-course of uptake of either toluidine blue or 14C-labelled benzoic acid ([14C] BA) along the length of the developing leaf. Toluidine blue uptake only occurred within the region 0–25 mm from the point of leaf insertion (POLI). Resistance—the inverse of permeance—to uptake of [14C] BA was determined for four leaf regions and was lowest in the region 10–20 mm above POLI. At 20–30 and 50–60 mm above POLI, it increased by factors of 6 and a further 32, respectively. Above the point of emergence of leaf three from the sheath of leaf two, which was 76–80 mm above POLI, resistance was as high as at 50–60 mm above POLI. GC-FID/MS analyses of wax and cutin showed that: (1) the initial seven fold increase in cuticular resistance coincided with increase in cutin coverage and appearance of waxes; (2) the second, larger and final increase in cuticle resistance was accompanied by an increase in wax coverage, whereas cutin coverage remained unchanged; (3) cutin deposition in barley leaf epidermis occurred in parallel with cell elongation, whereas deposition of significant amounts of wax commenced as cells ceased to elongate

The influence of iodine on the intensity of the intrathyroidal autoimmune process in graves' disease

Several lines of evidence support an etiological role of iodine for the initiation and perpetuation of autoimmune thyroid disease. However, varying relapse rates after increased iodine supplementation have been reported for Graves' disease. Furthermore the effects of iodine on the intensity of human autoimmune thyroiditis have previously only been investigated by indirect parameters and actions of iodine on thyroid function and a possible enhancement of the intrathyroidal autoimmune process in Graves' disease are difficult to separate in previous studies. Moreover lymphocytic thyroiditis in animal models has always been induced by considerably higher iodine doses as those used in in vivo studies. Therefore we investigated the effect of low and high iodine concentrations on the intensity of the intrathyroidal autoimmune process in Graves' disease. The intensity of intrathyroidal infiltration by lymphocytes, memory T cells, plasma cells and antigen presenting cells was determined by quantitative immunohistologic methods in 38 Graves' disease patients. 12 patients received additional preoperative iodine (group II) and 26 were treated with thiourelene antithyroid drugs only (group I). Urinary and intrathyroidal iodine concentrations were determined by a modified cer arsenit method in both groups. Application of high iodine doses in group II induced a significant increase of kappa and lambda positive plasma cells and interdigitating reticulum cells. This was not observed for activated T cells. There was no correlation between the extent of intrathyroidal infiltration by activated T cells, plasma cells and antigen presenting cells, and intrathyoidal or urinary iodine or intrathyoidal iodine concentrations in group I. High iodine doses therefore aggravate the intrathyoidal autoimmune process in Graves' disease by inducing an accumulation of immunocompetent cells involved in antigen presentation and antibody production. Howerver variations of iodine concentrations within the range encountered during antithyroid treatment do not seem to influence the number of intrathyoidal immunocompetent cells in established Graves' disease. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Cloning and expression analysis of candidate genes involved in wax deposition along the growing barley (Hordeum vulgare) leaf

The aim of the present study was to isolate clones of genes which are likely to be involved in wax deposition on barley leaves. Of particular interest were those genes which encode proteins that take part in the synthesis and further modification of very long chain fatty acids (VLCFAs), the precursors of waxes. Previously, it had been shown that wax deposition commences within a spatially well-defined developmental zone along the growing barley leaf (Richardson et al. in Planta 222:472–483, 2005). In the present study, a barley microarray approach was used to screen for candidate contig-sequences (www.barleybase.org) that are expressed particularly in those leaf zones where wax deposition occurs and which are expressed specifically within the epidermis, the site of wax synthesis. Candidate contigs were used to screen an established in-house cDNA library of barley. Six full-length coding sequences clones were isolated. Based on sequence homologies, three clones were related to Arabidopsis CER6/CUT1, and these clones were termed HvCUT1;1, HvCUT1;2 and HvCUT1;3. A fourth clone, which was related to Arabidopsis Fiddlehead (FDH), was termed HvFDH1;1. These clones are likely to be involved in synthesis of VLCFAs. A fifth and sixth clone were related to Arabidopsis CER1, and were termed HvCER1;1 and HvCER1;2. These clones are likely to be involved in the decarbonylation pathway of VLCFAs. Semi-quantitative RT-PCR confirmed microarray expression data. In addition, expression analyses at 10-mm resolution along the blade suggest that HvCUT1;1 (and possibly HvCUT1;2) and HvCER1;1 are involved in commencement of wax deposition during barley leaf epidermal cell development. Electronic supplementary material The online version of this article (doi:10.1007/s00425-007-0585-0) contains supplementary material, which is available to authorized users