Studies on the light controlling the time of flower-opening in Pharbitis nil

Flower buds of Pharbitis nil, strain Violet, open about 10 hrafter the onset of darkness at 24?C. Daylight fluorescent lightat 0.3–3 W/m² given during the first 4 hr of this darkperiod delayed the time of flower-opening, but that given laterhad only a slight effect or was ineffective. Red light was mosteffective in delaying the time of flower-opening, and a 5-minred light pulse given every 30 min also was effective. The effectof this 5-min red light was partly reversed by a subsequentfar-red light pulse which suggests that the absence of P_fr duringthe first 4 hr in the dark is necessary for normal timing offlower-opening. Five minutes of red light given 10 hr after the onset of darknessadvanced the phase of the circadian rhythm which controls thetime of flower-opening; buds opened about 7 hr earlier on thefollowing day. This effect of red light was also reversed bya subsequent exposure to far-red light, which suggests the participationof phytochrome in this reaction. (Received October 8, 1979; )     

Distinction between Clostridium botulinum type A strains associated with food-borne botulism and those with infant botulism in Japan in intraintestinal toxin production in infant mice and some other properties

In Bordetella pertussis virulence-associated genes, including adenylate cyclase toxin (Cya), are coordinately regulated in response to environmental signals by proteins coded by the bvg-locus. We have constructed cya-lac fusions in Escherichia coli and have shown that the cya operon is not expressed in E. coli, neither is it activated by bvg, when introduced in trans. The cya-lac fusion is fully active when returned to B. pertussis by homologous recombination and responds to bvg-dependent activation and environmental regulation. These results indicate that in B. pertussis the activation of the cya operon by bvg is indirect.     

Sequence Analysis of the 36-kb Region Between gntZ and trnY Genes of Bacillus Subtilis Genome*

Within the framework of an international Bacillus subtilis genomesequencing project, we have determined a 36-kb sequence coveringthe region between the gntZ and trnY genes. In addition to fivegenes sequenced and characterized previously, 27 putative proteincoding sequences (open reading frame; ORF) were identified.A homology search for the newly identified ORFs revealed thatsix of them had similarities to known proteins. It is notablethat new ORFs belonging to response-regulator aspartate phosphatase(Rap) and its regulator (Phr) families, and response regulatorand sensory kinase families of two-component signal transductionsystems have been identified. Furthermore, we found that some180-bp non-coding sequence, that might be an remnant of an ancientIS element, is preserved in at least five loci of the B. subtilisgenome.     

Effects of super-hard rice bread blended with black rice bran on amyloid β peptide production and abrupt increase in postprandial blood glucose levels in mice

Alzheimer’s disease and type 2 diabetes are very serious diseases with the latter having been suggested to cause the former. We prepared super-hard rice bread blended with black rice bran (SRBBB), which contained a high amount of resistant starch that showed strong inhibitory activities against β-secretase and acetylcholinesterase even after heating. Black rice bran showed greater β-secretase inhibitory activity (3.6-fold) than Koshihikari rice. The bran contained more oleic acid and anthocyanin, meaning that it is potentially a biofunctional food with a high antioxidant capacity. Furthermore, aged mice, which were fed a SRBBB diet for four weeks, showed lower amyloid β 40 peptide in the blood than mice fed a commercial diet (p < 0.01). Additionally, their initial blood glucose levels (BGLs) after 12 weeks of being fed SRBBB were significantly lower than those in the control group. Taken together, our results indicate SRBBB shows promise for inhibiting not only amyloid β production, but also abrupt increases in postprandial BGLs.     

Flower-Inducing Activity of Water Extracts of Various Plant Species, in Particular Pharbitis nil

The crude water extracts of leaves of many plant species belongingto Spermatophyta and some belonging to Bryophyta induced floweringof Lemna paucicostata 151 (PI51) under continuous light, atthe concentrations equivalent to 0.1 to 10 mg fr wt leaf per10 ml culture medium (mg fr wt/10 ml). The extract of Salvinia(Pterydophyta) added together with the extract of Lemna at aconcentration lower than that necessary to cause flowering alsoinduced flowering. The activity of the water extracts of someplants varied considerably from experiment to experiment dueto unknown factors, but the extracts of Pharbitis nil strainViolet, a sensitive short-day plant, always showed a high activity,as did the extracts of Lemna paucicostata reported previously. The extract of Pharbitis cotyledons induced flowering of P151even at 0.3 mg fr wt/10 ml, and significantly promoted floweringof L. paucicostata 441 and 6746 at 1–3 mg fr wt/10 ml.Ex-udate from the cuttings of the seedlings was also active.However, neither the activity of the water extract nor thatof the exudate could be correlated with photoperiodic floralinduction. On the other hand, the extract of leaves or cotyledonshad higher activity (on a fr wt basis) than that of other organs,and the activity of the extract of cotyledons changed with theirage roughly in parallel with their photoperiodic sensitivity. (Received April 17, 1989; Accepted August 10, 1989)     

Physical Basis of Flower-opening in Pharbitis nil

Flower buds of Pharbitis nil cut from plants growing in thefield open rapidly when subjected to darkness (20–25°C)or low temperature (20°C) in light. Petals of the buds arethe sites of photo- and thermo-perception; flower-opening iscaused mainly by the epinasty of petal midribs. ¹Dedicated to Professor Dr. Erwin Bunning on the occasion ofhis 75th birthday. (Received October 23, 1980; Accepted December 15, 1980)     

Sequence Analysis of the groESL-cotA Region of the Bacillus subtilis Genome, Containing the Restriction/Modification System Genes

We have determined a 35-kb sequence of the groESL-gutR-cotA(45°–52°) region of the Bacillus subtilis genome.In addition to the groESL, gutRB and cotA genes reported previously,we have newly identified 24 ORFs including gutA and fruC genes,encoding glucitol permease and fructokinase, respectively. Theinherent restriction/modification system genes, hsdMR and hsdMM,were mapped between groESL and gutRB, and we have identifiedtwo open reading frames (ORFs) encoding 5-methylcytosine formingDNA methyl transferase and an operon probably encoding a restrictionenzyme complex. The unusual genome structure of few ORFs andlower GC content around the restriction/modification genes stronglysuggests that the region originated from a bacteriophage integratedduring evolution.