Differential Induction of Lipoxygenase Isoforms in Wheat upon Treatment with Rust Fungus Elicitor, Chitin Oligosaccharides, Chitosan, and Methyl Jasmonate.

A glycopeptide elicitor prepared from germ tubes of the rust fungus Puccinia graminis Pers. f. sp. tritici Erikss. & Henn (Pgt), as well as chitin oligosaccharides, chitosan, and methyl jasmonate (MJ) stimulated lipoxygenase (LOX) activity (E.C. 1.13.11.12) in wheat (Triticum aestivum) leaves. Immunoblot analysis using anti-LOX antibodies revealed the induction of 92- and 103-kD LOX species after Pgt elicitor treatment. In contrast, MJ treatment led to a significant increase of a 100-kD LOX species, which was also detected at lower levels in control plants. The effects of chitin oligomers and chitosan resembled those caused by MJ. In conjunction with other observations the results suggest that separate reaction cascades exist, and that jasmonates may not be involved in Pgt elicitor action. LOX-92 appears to be mainly responsible for the increase in LOX activity after Pgt elicitor treatment because its appearance on western blots coincided with high LOX activity in distinct anion-exchange chromatography fractions. It is most active at pH 5.5 to 6.0, and product formation from linoleic and [alpha]-linolenic acid is clearly in favor of the 9-LOOHs. It is interesting that a 92-kD LOX species, which seems to correspond to the Pgt elicitor-induced LOX species, was also detected in rust-inoculated leaves.

[Incidence of autonomy and immune hyperthyroidism before and following preventive use of iodized salt in the Berlin-Brandenburg area]. / Inzidenz von Autonomie und Immunhyperthyreose vor und nach Jodsalzprophylaxe in der Region Berlin-Brandenburg.

The incidence of hyperthyroidism was observed in the area of Berlin (1.2 million inhabitants) and in a rural district in the geographical region of the "Mark Brandenburg" (48.115 inhabitants) during the period from 1975 und 1989. This area is characterized with a iodine deficiency grade II (WHO). In 1985 an iodine salt supplementation was introduced by law. The period before iodine salt supplementation 1975-1985 was compared to the period after iodine prophylaxis: there was an increase in hyperthyroidism in the Berlin-area by the ratio 1:3.1 and 1:2.8 (1975-83 compared to 1988 and 1989), in the rural district by 1:1.7 (1980-1985 compared to 1986/87). The ratio autonomy (non immunogenic form) to immunogenic etiology was 1:12 (1977-83), and changed to 1:1.45 in 1988 and 1:16.3 in 1989 after iodine supplementation. The sex ratio male:female was 1:10 before, and 1:6.8 after prophylaxis for hyperthyroidism in total, in autonomy the ratio was observed as 1:12 before and 1:7.7 (1988), 1:4.7 (1989) after supplementation, in immunogenic hyperthyroidism 1:10 unchanged in the early and late period of observation. The increase of hyperthyroidism after iodine prophylaxis correlated well with the consumption of thyrostatic drug Thiamazol (Methimazol) for the whole country. The defined daily dose (DDD)/1000 inhabitants/day increased during the observation time from 0.5 (1984), 0.55 (1985), 0.66 (1986), to 1.47 (1987), 1.26 (1988) and 0.81 (1989). The results are compared and discussed with reports from USA, Iceland, Great Britain, Denmark, Italy and Tasmania. During the period of seven years (1980-87) in the rural district a seasonal dependence of onset in hyperthyroidism was observed in spring time between May and June only in immunogenic hyperthyroidism, despite in thyroidal autonomy the disease began throughout the year without a seasonal peak.

The relationship between oxidase activity, peroxidase activity, hydrogen peroxide, and phenolic compounds in the degradation of indole-3-acetic acid in vitro.

The peroxidase catalyzed degradation of indole-3-acetic acid (IAA) results in the formation of indole-3-methanol (IM) in the presence of phenolic compounds or in 3-hydroxymethyloxindole (HMOx) in their absence. Apparently the phenols compote with a methyleneindolenine intermediate for H2O2 which is produced by oxidase action preceding the peroxidase action in the course of IAA degradation. The substitution pattern of various phenolic compounds tested strongly effects the rate of the reaction. However, this substitution pattern does not appear to effect the type of the reaction or the products formed. We suggest that the function of the "oxindole pathway" is to detoxify excess H2O2 in the absence of phenolic cosubstrates. The results lead to a number of interesting aspects of IAA biochemistry and to the proposal of a new reaction scheme for the peroxidase catalyzed degradation of IAA.

Cell division and plant development from protoplasts of carrot cell suspension cultures.

Cell regeneration and sustained division have been observed in protoplasts from carrot cell suspension cultures. Carrot plants were produced from the protoplasts by embryogenesis.