Effects of Na2SO4, K2SO4 and KCl on Growth and Ion Uptake of Callus Cultures of Vaccinium corymbosum L. cv. Blue Crop

Non-selected and Na₂SO-, K₂SO₄- or KCl-selected callus culturesof Vaccinium corymbosum L. cv. Blue Crop were grown on mediasupplemented with 0, 25 and 50 mM Na₂SO₄ (non-selected and Na₂SO(-selectedonly), 0, 25 and 50mMK₂SO₄ (non-selected and K₂SO₄-selectedonly) or 0, 50 and 100 mM KCl (non-selected and KCl-selectedonly). On all media, growth of selected callus (on a fresh-weightor dry-weight basis) was greater than that of non-selected callus,and selected callus grew optimally on the level and type ofsalt on which it was selected. Selected callus was friable andmaintained a higher f. wt:d. wt ratio. Tissue water potentialin selected callus was more negative than in non-selected callus. Flame photometry and chloridometry showed Na⁺, K⁺ and Cl^–accumulated in callus to concentrations equal to or greaterthan the initial concentration in the medium. Turbidometry showedthat tissue SO₄^2- concentration was lower than the concentrationin the medium. In most cases selected callus accumulated moreNa⁺, K^sup, SO₄^2– or Cl^– than non-selected callus.Vacuolar ion concentration was measured by electronprobe X-raymicroanalysis, and on most media selected callus had highervacuolar ion concentrations than non-selected callus. SO₄^2–and Cl^– were accumulated in the vacuoles at concentrationshigher than the external medium, but vacuolar Na⁺ concentrationdid not reach external concentration on Na₂SO₄ and on potassiumsalts was maintained between 12 and 17 mM. Vacuolar K⁺ concentration(approx. 142–191 mM on no salt) decreased on Na₂SO₄ andincreased on K₂SO₄ and KCl. There was no precise correlation between total or specific ionaccumulation (Na⁺, K⁺, SO₄^2– and Cl^– and fresh-weightyield. Results suggest that selection results in adaptationin response to decreased water potential of the medium. Vaccinium corymbosum, blueberry, electronprobe X-ray microanalysis, callus, in vitro selection, salt tolerance, KCl, K₂SO₄, Na₂SO₄     

固氮蓝藻高光放氢突变种的筛选和放氢特点

作者以前报道过几种快速生长的固氮蓝藻在某种条件下能好气光放氢,其速度可以达到光合放氧速度的10—15%,但这种活性只有在不积累氢气的流动气相下或在短时间内发生。本文报道用亚硝基胍诱变所得到的Anabaena spp。Strain CA的高光放氢突变种——N9A和18A——的筛选和氢代谢特点。在达生长饱和光照以后,野生型的光放氢活性与光照强度的增加成正相关,而其吸氢活性则与之成负相关,显示高光照强度可能抑制吸氢酶的活性。无论在什么光强下,均测不到两个突变种的吸氢活性,暗示在突变种中,吸氢酶或有关系统受损伤。把细胞固相化在琼脂上,在密闭系统中,高光强下培养50个小时,两个突变种光释放和积累的氢分别为野生型的2倍(N9A)和6倍(18A),后者等于氢占气相(1%CO_2的空气)的1.8%。两个突变种在生长速度、叶绿素含量、乙炔还原活性以及光合放氧方面与野生型无明显不同。当以含50—100nM的镍离子的培养基培养时,野生型的好气净产氢活性完全丢失,其吸氢活性却增加约10倍。培养基中镍离子的存在,对两个突变种的高光放氢活性则毫无影响,而且在此情况下,仍测不出其吸氢活性。实验结果表明,这两个突变种系吸氢酶缺陷型突变种。     

Tissue 11In vitro Bud Formation on Explants from the Inflorescence of Nicotiana tabacum L.

Croes, A. F., Creemers-Molenaar, T., van den Ende, G., Kemp,A. and Barendse, G. W. M. 1985. Tissue age as an endogenousfactor controlling in vitro bud formation on explants from theinflorescence of Nicotiana tabacum L.—J. exp. Bot. 36:1771–1779. The in vitro formation of generative buds was studied on explantsfrom flower and fruit stalks and from internodes of the floralramifications of tobacco. A floral gradient was found to existalong the axis of the branch. The gradient concerns the numberof flower buds formed in vitro and is present in both typesof tissues. The number of flower buds is greater on tissuesfrom the apical than from the basal portion of the branch. Thecapacity to generate these buds is largely determined by tissueage at the moment of the excision. Consequently, the gradientmoves along the axis during the outgrowth of the inflorescence. The alternative possibility that some apex-derived stimuluspredetermines the morphogenetic capacity of the tissue priorto excision is excluded by the observation that the gradientremains virtually unaltered if the apex is removed one weekbefore the onset of culturing. Auxin affects the floral gradient Increasing the auxin concentrationin internode tissue culture causes a steeper gradient of flowerbud generation by almost completely abolishing bud formationon older tissues. Key words: Auxin, flower buds, gradient, tissue culture, tobacco     

Fluorescein-Conjugated Folate as an Indicator of Specific Folate Binding to Paramecium1

Normal Paramecium tetraurelia cells stained with fluorescein-conjugated folate show intense fluorescence that can be reduced to near background autofluorescence with excess K₂-folate, but not with excess KCl. Mutant d4–534, which is not attracted to folate and does not specifically bind ³H-folate, shows reduced fluorescence when stained. This method of monitoring specific folate binding to cells can be adapted to a microscale for rapid screening of clones since cells are routinely fixed and stained in microtiter wells.     

Floristic altitudinal zones in Malesia

From the altitudinal ranges of species recorded for the Malesian mountain flora, in Flora of Java and the 6 or so volumes of Flora Malesiana it was concluded that there are critical altitudes where the floristic composition shows rather abrupt demarcations, namely at 1000, 1500, 2400 and 4000 m altitude. In a generalized way this also holds for the structure and stature of the vegetation. For cultivated plants the altitudes of 1000 and 1500 m are also distinct demarcations.     

Proficiency testing of water microbiology laboratories in The Netherlands

In a 3-year period, four series of simulated water samples containing selected test strains were distributed to more than 50 laboratories in The Netherlands for bacteriological testing. Participating laboratories examined the samples by enrichment or membrane filtration methods, or both, for total coliform organisms, thermotol-erant coliform organisms, faecal streptococci and standard plate counts (37˙ and 22˙C) according to Dutch standard methods. The results were quantitatively satisfactory: the distribution of positive and negative results with subsamples conformed to stochastic variation; the standard deviation of membrane or plate counts was usually in the range which may be expected from a Poisson distribution, and there was good correspondence between average counts in participating laboratories and those expected from controls in the organizing laboratory. Problems of a qualitative nature were frequently encountered, however. Among them were a false positive response with a strain of Enterobacter cloacae in the thermotolerant coliform test; a false positive result with Clostridium perfringens in enrichment tests for total or thermotolerant coliform organisms and false positive results with Micrococcus varians in the faecal streptococcus test by membrane filtration. It is concluded that quality assessment should be a consistent activity in water microbiology laboratories. For this purpose, stable and well characterized reference materials are needed.     

Structure of the “Peroxy-Y Base” from Liver tRNA<Superscript>Phe</Superscript>

WE wish to report that reconstituted sperm whale myoglobin prepared by the method of Breslow¹ (except that pH 2 was found sufficient to remove all the haem) (I) crystallizes² in a different habit from those prepared by the method of Rossi-Fanelli et al.³ (II) using haemin of Sigma lot 77B-0220 and our own ⁵⁷Fe photoporphyrin preparation and the native myoglobin (III). Although all three form type A³ monoclinic prisms, the best developed plane is [001] for II and III, it is [100] for I. There seems to be great interest in reconstituted haemoproteins^4,5, so it is important that crystallization habit may be a sensitive test for subtle changes in protein structures.     

The effect of injury and infection by Gibberella zeae on the polyacrylamide gel electrophoretic pattern of soluble proteins in potato tuber tissue

Polyacrylamide gel electrophoretic patterns of soluble proteinsfrom intact potato tubers and from wounded tuber tissue wereidentical. The patterns from diseased tissue showed some minordifferences not before 3–4 days after inoculation. Itis concluded that primarily proteins of minor fractions areinvolved in protein synthesis after wounding or infection. (Received March 22, 1969; )     

The Respiratory Metabolism of Strelitzia juncea Ait. Seeds. The Effect of Dormancy Release by Oxygen on certain Glycolytic Enzyme Activities and Metabolite Concentrations

The activity of the glycolytic enzymes PFK, PFP, PK and aldolaseas well as the content of glucose, fructose, glucose-6-phosphateand fructose-6-phosphate were compared in the embryos of airand oxygen-incubated seeds of Strelitzia juncea. Determinationswere made during the first 4 d of incubation, prior to radicleemergence, which commences on day five for oxygen-treated seeds. No difference in PFK activity was found for the two treatments,and for both treatments PFK tended to increase with the incubationperiod. The fr2, 6P₂-stimulated PFP activity was slightly higherfor oxygen-incubated seeds, and showed a significant increasein activity over the 4 d incubation period for both treatments.No significant change in the general trend of PK and aldolaseactivity resulted from incubating the seeds in oxygen. The almost equimolar glucose and fructose contents of the embryoswere lower after 1 d of oxygen incubation of the seeds, andthe content decreased sharply during the incubation period.It is concluded that a moderate increase in the glycolytic capacityof embryos resulted from oxygen treatment of S. juncea seeds. Key words: Dormancy, glycolysis, Strelitzia juncea