Methylation of the Flagellin of Salmonella typhimurium

The methylation of endogenous proteins by Salmonella typhimurium SL 870 was investigated in cell-free extracts by using S-adenosylmethionine as methyl donor. Several lines of evidence are presented which suggest that one of the methylated products is the protein flagellin. Mutant strains of SL 870 (nml⁻fla⁺ and nml⁺fla⁻) were also found to synthesize epsilon-N-methyl-lysine. It is proposed that S. typhimurium possesses at least two genes specifying different methylating enzymes. One gene product is a flagellin-specific methylating enzyme, whereas the other gene(s) codes for enzymes that methylate one or more other cell proteins.     

Reduction of potassium tellurite by Candidas

Summary A technique for observing the reduction of potassium tellurite byCandidas was developed. Various species of these yeasts reduce it at different concentrations, but that which is most useful for differentiation is 0.02 % added to Sabouraud dextrose agar basal medium. Of the yeasts studied,C. albicans, C. parapsilosis andC. tropicalis all reduced potassium tellurite to the concentration mentioned before, while the growth ofC. krusei, C. parakrusei andC. pseudotropicalis was inhibited. Without exception,C. pseudotropicalis reduced this salt at lower concentrations. The two strains ofC. guilliermondii tested gave contradictory results: one of them grew and reduced potassium tellurite, while the growth of the other was inhibited.Professor of Microbiology.     

Sex expression in floral buds of Acorn squash

Summary Staminate flowers of the Acorn squash (Cucurbita pepo, cv. Table Queen) are initiated monosexually, pistillate flowers are initiated bisexually. Pistillate flower primordia are physiologically bisexual from a stage below 0.3 mm until they are 0.8 mm in width.Male and female floral buds were cultivated on White's medium, modified according to Galun et al. (1963). In excised female floral buds the relative development of stamens is better than in in-situ floral buds; the opposite relationship holds for ovary development. The smaller the bud at excision, the greater the stamen growth and the lesser the ovary growth, both in absolute and relative terms. Although smaller pistillate floral buds cultured in vitro showed a greater increase in maleness than larger ones, there was no difference in the percentage of female buds between explants of the two sizes when originating from the mixed stem region (that is, the stem region carrying male and female flowers). Addition of 3-indoleacetic acid and the anti-auxin p-chlorophenoxyisobutyric acid to standard medium in equal amounts resulted in somewhat better development of excised floral buds than addition of each of these compounds alone.The percentage of female buds among explants originating from identical nodes was not significantly influenced by 3-indoleacetic acid or p-chlorophenoxyisobutyric acid.Weizmann Memorial Fellow. The studies reported in this publication were mainly undertaken at the Weizmann Institute of Science     

Relationship of indole-3-butyric acid and adventitious rooting in M.26 apple (Malus Pumila mill.) shoots cultured in vitro

The role of indole-3-butyric acid (IBA) in adventitious root formation was studied by analyzing the uptake and subsequent metabolism of IBA in shoots of M.26 apple (Malus pumila Mill.) rootstock grown in vitro. Roots were induced by exposing shoots to 4 M IBA and [³H]IBA for 5 days in the dark and then transferring them to plant growth regulator (PGR)-free medium in the light until roots formed. Approximately 50% of the total radioactivity applied was taken up from the agar medium by the shoots during the 5-day incubation period in IBA. Indole-3-butyric acid metabolism was studied by extraction and high-performance liquid chromatographic (HPLC) separation of [³H]IBA and metabolites from the basal sections of treated shoots. The major [³H]IBA metabolite co-eluted with authentic [¹⁴C]indole-3-acetic acid (IAA) suggesting that IBA was converted to IAA in the shoots. The proportion of newly synthesized IAA present as conjugates was higher at the end of the 5-day IBA treatment period than after 13 days in PGR-free medium. There appeared to be no conjugation of IBA at any time.     

Effect of immune system imagery on secretory IgA

This study was an investigation of the effects of physiologically-oriented mental imagery on immune functioning. College students with normal medical histories were randomly selected to one of three groups. Subjects in Group 1 participated in short educational training on the production of secretory immunoglobulin A. They were then tested on salivary IgA, skin temperature, and the Profile of Mood States (POMS) before and after listening to a 17-minute tape of imagery instructions with specially composed background entrainment music designed to enhance imagery. Subjects in Group 2 (placebo controls) listened to the same music but received nor formal training on the immune system. Group 3 acted as a control and subjects were tested before and after 17 minutes of no activity. Treatment groups listened to their tapes at home on a bi-daily basis for six weeks All groups were again tested at Weeks 3 and 6. Secretory IgA was analyzed using standard radial immunodiffusion techniques. Repeated measures analyses of variance with planned orthogonal contrasts were used to evaluate the data. Significant overall increases (p<0.05) were found between pre- and posttests for all three trials. Groups 1 and 2 combined (treatment groups) yielded significantly greater increases in sIgA over Group 3 (control) for all three trials. Group 1 (imagery) was significantly higher than Group 2 (music) in antibody production for Trials 2 and 3. Symptomatology, recorded by subjects at Weeks 3 and 6, was significantly lower for three symptoms (rapid heartbeat, breathing difficulty, and jaw clenching), favoring both treatment groups over the control group.