Morphology and Hormone Levels of Tobacco and Carrot Tissues Transformed by Agrobacterium tumefaciens I. Auxin and Cytokinin Contents of Cultured Tissues Transformed with Wild-Type and Mutant Ti Plasmids

Carrot and tobacco plants were transformed with Agrobacteriumtumefaciens harboring wild-type, aux^– or cyt^– Tiplasmids. In tobacco, these wild and mutant Ti plasmids inducedthe formation of non-morphogenic galls, galls with shoots, andgalls with roots, respectively. In carrot, however, transformationwith any of these plasmids resulted in only the formation ofamorphous tumors. Determination of IAA and cytokinin contentsshowed that in tobacco, significantly high amounts of cytokininsor IAA are present in the cells transformed with Ti plasmidspossessing cytokinin or IAA biosynthetic genes, respectively.In carrot, cytokinin contents were also high in the cells transformedwith Ti plasmids having cytokinin biosynthetic genes, whereasIAA contents of the cells were similar regardless of the plasmidsused for transformation. These results suggest that the mechanism regulating IAA metabolismmay be different in tobacco and carrot. (Received June 25, 1987; Accepted February 1, 1988)     

Morphology and Hormone Levels of Tobacco and Carrot Tissues Transformed by Agrobacterium tumefaciens II. IAA Biosynthetic Activity of Cultured Carrot Tissues Transformed with Wild-Type and Mutant Ti Plasmids

IAA biosynthetic activity was examined in cultured carrot tissuestransformed with Agrobacterium tumefaciens harboring wild-type,aux^– or cyt^– Ti plasmids. In vitro IAAM hydrolaseactivities in tissues transformed with wild-type, and cyt^–Ti plasmids were 3.09 and 19.82 nmol/g proteins/30 min, respectively,but not detectable when aux^– Ti plasmids were used. Theactivity of IAA biosynthesis, determined by the incorporationof radioactivity into IAA in tissues fed with [¹⁴C]-tryptophan,was 34.13, 10.92 and 32.47 pmol/g fr wt/30 min in tissues transformedwith wild type, aux^– and cyt^– Ti plasmids, respectively.The incorporation of radioactivity into the IAAM fraction wasdetected only in the tissues transformed with wild type andcyt^– Ti plasmids. These results showed that the T-DNAencoded pathway of IAA biosynthesis was active in tissues transformedwith wild-type and cyt^h Ti plasmids, and that the activity ofIAA biosynthesis in those tissues was higher than that in tissuestransformed with the aux^– Ti plasmid. (Received March 16, 1988; Accepted July 31, 1988)     

Construction of a fusion gene comprising the Taka-amylase A promoter and the Escherichia coli β-glucuronidase gene and analysis of its expression in Aspergillus oryzae

Summary Northern blot analysis of glucose-grown and starch-grown mycelia of Aspergillus oryzae R11340 was conducted using the cloned Taka-amylase A (TAA) gene as a probe. The amount of mRNA homologous to the TAA gene was increased when this fungus was grown with starch as a sole carbon source. In order to analyze the induction mechanism, we inserted the Escherichia coli uidA gene encoding -glucuronidase (GUS) downstream of the TAA promoter and introduced the resultant fusion gene into the A. oryzae genome. Production of a functional GUS protein was induced by starch, but not by glucose. When the effects of various sugars on expression of the fusion gene were examined, the results suggested that the expression of the fusion gene was under control of the TAA gene promoter.     

Comparison of intraspecific nest usurpation between two haplometrotic paper wasp species (Hymenoptera: Vespidae:Polistes)

Intraspecific nest usurpation by foundresses was studied in 2 haplometrotic (solitary founding) species of different subgenera,Polistes (P.) riparius andP. (Polistella) snelleni, in areas where they cohabited. The overall probability for a nest to be usurped by a foreign foundress during the season was about twice as large inP. snelleni as inP. riparius. In both, however, probability of usurpation was largest on late pre-emergence nests, or in late June and early July. InP. riparius, all the usurpers of known origins were those foundresses that had lost their pre-emergence nests to destruction probably by some vertebrates; inP. snelleni, some usurpers had the same history as above, while the others had lost many of all larvae to predation by unknown agents before worker emergence. Usurpers of both species destroyed eggs and younger larvae to much greater extents than older larvae or pupae, and they produced fewer numbers of reproductives in comparison with non-usurping foundresses. We concluded that usurpation behavior has been maintained despite its relatively low productivity because renesting would lead to even lower or no reproductive production.     

Changes in aerobic and anaerobic ATP-synthesizing activities in hypoxic mouse brain

The changes in cerebral metabolism in mice in severe hypoxia were investigated by analyses of changes in the levels of energy metabolites and near-infrared spectrophotometric assessment of the states of hemoglobin and cytochrome oxidase. Under 4.4% O2, the contribution of anaerobic ATP production was at most about 20% of the demand. However, the cerebral ATP level was kept at the control level until about 1 min before death. Pentobarbital anesthesia, which reduced the cerebral rate of metabolism, prolonged the survival time, although anaerobic ATP production still did not support ATP demand. Under these conditions, deoxygenation of hemoglobin and reduction of cytochrome oxidase proceeded rapidly within 1 min. Hemoglobin reached the maximum state of deoxygenation in the middle phase of hypoxia, with no further change until death. However, cytochrome oxidase was reduced slowly with one phase of partial reoxidation due to increase of cerebral blood volume, and reached the completely reduced state at death. From these results it was concluded that the aerobic ATP synthesis, which supplied more than 80% of the cerebral demand, decreased gradually because of limitation of oxygen supply, and that the failure of oxidative phosphorylation to meet demand triggered the decrease in the cellular ATP level that led to death.     

Formation of cobalt-porphyrin by Corynebacterium simplex grown on hydrocarbon media

A vitamin B₁₂-producing and hydrocarbon-utilizing bacterium, Corynebacterium simplex, accumulated an appreciable amount of cobalt-porphyrin in cultural filtrates when grown on a n-hexadecane medium containing sufficient amounts of cobaltous sulfate and an appropriate detergent. When grown without the detergent, the cobalt-porphyrin was found only in the cells of the organism. In the latter case, the content of cobalt-porphyrin was comparable to that of vitamin B₁₂ and 7 times lower than that of iron-porphyrin. Though the organism required cobaltous sulfate for optimal growth, the requirement could be efficiently replaced by the supplementation of cobalt-porphyrin and partly of vitamin B₁₂. The porphyrin moieties of extra- and intracellular cobalt-porphyrin were identified as coproporphyrin III in both cases.     

Effect of dietary tin deficiency on growth and mineral status in rats

To clarify the influence of dietary tin deficiency on growth and mineral status, the following two different synthetic diets were fed to male Wistar rats: group 1—a diet containing 1.99 μg tin/g; group 2—a diet containing 17 ng tin/g. The rats in group 2 showed poor growth, lowered response to sound, and alopecia, with decreased food efficiency compared with rats in group 1. The changes of mineral concentrations in tissues observed in group 2, compared with group 1, are summarized as follows: calcium concentration in lung increased; magnesium concentration in lung decreased; iron concentrations in spleen and kidney increased; iron concentration in femoral muscle decreased; zinc concentration in heart decreased; copper concentrations in heart and tibia decreased; manganese concentrations in femoral muscle and tibia decreased. These results suggest that tin may be essential for rat growth.     

Resuscitation of Vibrio cholerae O1 strain TSI-4 from a viable but nonculturable state by heat shock

Abstract Vibrio cholerae strain TSI-4 was incubated in an M9 salt solution at 15 °C for more than 100 days. The plate counts showed no viable cells on day 30, but a broth culture from that day showed the growth of bacteria. However, after 35 days the bacteria entered the nonculturable state, based on the assessment of both the plate counts and broth culture. A portion of the culture was heated at 45 °C for 1 min in a water bath and subsequently plated onto a nutrient agar plate. More than 1000 colonies were recovered after this heat-shock treatment. The recovered cells showed the same chromosomal DNA pattern in the restriction map and the same outer membrane protein pattern in SDS-PAGE. Recovery of viable cells by heat-shock was achieved in cultures grown on M9 salt but not from cultures grown in phosphate-buffered saline. This suggests that the presence of NH₄Cl in the M9 salt solution may support the growth of the bacteria in a low nutrient medium, while also playing an important role in resuscitation.     

Neurological disorder and excessive accumulation of calcium in brain of clinically vitamin A-deficient rats

Three groups of rats were fed two types of synthetic diets for 52 d. The—A group was allowed free access to a vitamin A-deficient diet and showed classical signs of vitamin A deficiency. The brain was the only organ in our experiment where no significant weight difference was present among the three groups. In the brain, calcium concentration was significantly higher in the—A group when compared with the PF (Pair-fed; allowed restricted amount of control diet) and +A groups (allowed free access to control diet). In the tibia, calcium and magnesium concentrations were significantly lower in the—A group when compared with other two groups. Excessive accumulation of calcium in brain and apparently similar unbalance in bone, mineral concentration were observed in central nervous system (CNS) degenerative diseases. Our results suggest that abnormal metabolism of calcium and magnesium in some tissues and excessive accumulation of calcium in brain may be responsible for the development of neurological disorders in vitamin A-deficient rats.