Spontaneous chlorophyll mutants of Pennisetum americanum: Genetics and chlorophyll quantities

Summary Thirteen spontaneously occurring chlorophyll deficient phenotypes have been described and their genetic basis was established. Ten of these — white, white tipped green, patchy white, white virescent, white striping 1, white striping 2, white striping 4, fine striping, chlorina and yellow virescent showed monogenic recessive inheritance and the remaining three — yellow striping, yellow green and light green seedling phenotypes showed digenic recessive inheritance. The genes for (i) white tipped green (wr) and yellow virescent (yv) and (ii) patchy white (pw) and white striping 1 (wst 1) showed independent assortment. Further, the genes for white (w), white tipped green (wr) and yellow virescent (yv) were inherited independently of the gene for hairy leaf margin (Hm).In the mutants — white tipped green, patchy white, white striping 1, white striping 2, fine striping, chlorina, yellow virescent, yellow striping, yellow green and light green phenotypes total quantity of chlorophyll was significantly less than that in the corresponding controls, while in white virescent there was no reduction in the mature stage. For nine of the mutants the quantity of chlorophyll was also estimated in F₁'s (mutant x control green). In F₁'s of six of the mutants — white tip, patchy white, chlorina, yellow virescent, fine striping and yellow striping the quantity of chlorophyll was almost equal to the wild type. In the F₁'s of three of the mutants — white striping 1, white striping 2 and light green an intermediate value between the mutant and wild types was observed. In yellow virescent retarded synthesis of chlorophyll, particularly chlorophyll a was observed in the juvenile stage. Reduced quantity of chlorophyll was associated with defective chloroplasts. In the mutants — white tipped green, white virescent, fine striping, chlorina, yellow striping, yellow green and light green defective plastids were also observed. In patchy white secondary destruction of chlorophylls and the presence of defective plastids were found to be associated with reduced chlorophyll quantity at maturity.Paper chromatographic studies of leaf flavonoids revealed some variation between the inbreds, but there were three common spots, 7, 8 and 9, except for PDP in which the spot 8 was absent. Chlorophyll deficient mutants differed from their respective controls in the absence of one or more of the spots present in the controls and in the presence of new spots in some of the mutants.Most of the chlorophyll mutants showed higher survival rate in the Kharif season than in Rabi season which was attributed to the higher mean day temperature and longer day light period in the Kharif season than in Rabi season.     

The formation of peptides from the 2′(3′)-glycyl ester of a nucleotide

Summary We have synthesized 2(3)-O-(glycyl)-adenosine-5-(O-methylphos-phate), an analogue of the 3-terminus of aminoacylated tRNA. A 0.4M solution of this compound maintained at pH 8.2, yields 5.5% of diglycine and 11.5% of diketopiperazine, in addition to the hydrolysis products glycine and adenosine-5-(O-methylphosphate). Under the same conditions, glycine ethyl ester reacts much more slowly, but ultimately gives similar yields of diglycine and diketopiperazine.The aminolysis of 2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate) by free glycine is relatively inefficient, but serine reacts 20 times more rapidly and yields up to 50% of N-glycylserine. The prebiotic significance of these reactions is discussed.Abbreviations MepA adenosine-5-(O-methylphosphate) - MepA-gly 2(3)-O-(glycyl)-adenosine-5-(O-methylphosphate) - MepA-bis-gly 2,3-O-(bis-glycyl)-adenosine-5-(O-methylphosphate) - DKP diketopiperazine - gly Et glycine ethyl ester - gly-ser N-glycylserine - O-gly-ser O-glycylserine - O-(gly)-gly-ser O-(glycyl)-glycylserine - Boc-gly N-tert-butyloxycarbonylglycine - MepA-Boc-gly 2(3)-O-(Boc-glycyl)-adenosine-5-(O-methylphosphate) - MepA-bis-Boc-gly 2,3-O-(bis-Boc-glycyl)-adenosine-5(O-methylphosphate) - (gly)₂ diglycine - (gly)₃ triglycine     

Comparative Modulation by 3α,5α and 3β,5β Neurosteroids of GABA Binding Sites During Avian Central Nervous System Development

Neurosteroids are endogenous Central Nervous System (CNS) compounds which act mainly by allosteric modulation of the GABA_A receptor complex. The presence of a 3-hydroxyl group and a 5-hydrogen atom have been found to be essential structural requirements for biological activity in mammals. In the present work we report the enhancing activity on [³H]GABA binding to its receptor sites in chick optic lobe produced by progesterone metabolites 3-hydroxy,5-pregnan-20-one (3,5-P) and 3-hydroxy,5-pregnan-20-one (3,5-P). Both steroids were found able to enhance [³H]GABA binding along ontogeny, displaying a similar profile at early developmental stages, while in adulthood 3,5-P had greater potency (EC₅₀ 0.22 M) and enhancing effect (E_max: 122%). In adult synaptic membranes, the two compounds displayed a complex interaction with the GABA_A receptor, disclosed by a Schild plot with slope below one and an incomplete displacement of 3,5-P by its 3,5 isomer. Such complexity could be related to the steroidogenic profile in avian CNS, with 5-reduced progesterone metabolites present since early development, while 3,5-P is found only in adulthood. Bearing in mind differences between avian and mammalian steroidogenic profiles and the relevance of 5-steroids in early avian development, we propose that 3,5-P, instead of the classical potent 3,5-steroids, may be the endogenous modulator of GABAergic activity in developing avian brain.     

On age morphological changes of males of Chydoridae (Cladocera)

Summary Young and adult males of 11 species of Chydoridae are studied, their figures being published here (fig. 1–15). The necessity is stressed to distinguish young forms of males and gynandromorphic individuals.Pleuroxus balatonicus is considered to be described from the population ofPleuroxus unicatus having under Balaton Lake conditions retarded transformation of young males into adult form, and accordingly having unusually numerous young males. \qO\qs\qn\qo\qv\qn\qy\ye \qr\ye\qz\qu\ql\Qj\qt\qa\qt\qy 11 (. 1–15). . , Pleuroxus uncinatus , Pleuroxus balatonicus.     

Variation of seed α-amylase inhibitors in the common bean

Variation of seed -amylase inhibitors was investigated in 1 154 cultivated and 726 non-cultivated (wild and weedy) accessions of the common bean, Phaseolus vulgaris L. Four -amylase inhibitor types were recognized based on the inhibtion by seed extracts of the activities of porcine pancreatic -amylase and larval -amylase and larval -amylase of the Mexican bean weevil, Zabrotes subfasciatus Boheman. Of the 1 880 accessions examined most (1 734) were able to inhibit porcine pancreatic -amylase activity, but were inactive against the Z. subfasciatus larval -amylase; 41 inhibited only the larval -amylase activity, 52 inhibited the activities of the two -amylases, and 53 did not inhibit the activity of either of the -amylases. The four different inhibitor types were designated as AI-1, AI2, AI-3, and AI-0, respectively. These four inhibitor types were identified by the banding patterns of seed glycoproteins in the range of 14–20 kDa by using SDSpolyacrylamide gel electrophoresis. Additionally, four different banding patterns were recognized in accessions with AI-1, and were designated as AI-1a, 1b, 1c, and 1d. Two different patterns of the accessions lacking an -amylase inhibitory activity were identified and designated as AI-0a and AI-0b. The largest diversity for seed -amylase inhibitors was observed in non-cultivated accessions collected from Mexico where all eight inhibitor types were detected. The possible relationships between the variation of seed -amylase inhibitors and bruchid resistance are discussed.     

Carbon and nitrogen isotope ratios in different compartments of a healthy and a declining Picea abies forest in the Fichtelgebirge,NE Bavaria

Summary Natural carbon and nitrogen isotope ratios were measured in different compartments (needles and twigs of different ages and crown positions, litter, understorey vegetation, roots and soils of different horizons) on 5 plots of a healthy and on 8 plots of a declining Norway spruce (Picea abies (L.) Karst.) forest in the Fichtelgebirge (NE Bavaria, Germany), which has recently been described in detail (Oren et al. 1988a; Schulze et al. 1989). The ¹³C values of needles did not differ between sites or change consistently with needle age, but did decrease from the sun-to the shade-crown. This result confirms earlier conclusions from gas exchange measurements that gaseous air pollutants did no long-lasting damage in an area where such damage was expected. Twigs (¹³C between-25.3 and-27.8) were significantly less depleted in ¹³C than needles (¹³C between-27.3 and-29.1), and ¹³C in twigs increased consistently with age. The ¹⁵N values of needles ranged between-2.5 and-4.1 and varied according to stand and age. In young needles ¹⁵N decreased with needle age, but remained constant or increased in needles that were 2 or 3 years old. Needles from the healthy site were more depleted in ¹⁵N than those from the declining site. The difference between sites was greater in old needles than in young ones. This differentiation presumably reflects an earlier onset of nitrogen reallocation in needles of the declining stand. ¹⁵N values in twigs were more negative than in needles (-3.5 to-5.2) and showed age- and stand-dependent trends that were similar to the needles. ¹⁵N values of roots and soil samples increased at both stands with soil depth from-3.5 in the organic layer to +4 in the mineral soil. The ¹⁵N values of roots from the mineral soil were different from those of twigs and needles. Roots from the shallower organic layer had values similar to twigs and needles. Thus, the bulk of the assimilated nitrogen was presumably taken up by the roots from the organic layer. The problem of separation of ammonium or nitrate use by roots from different soil horizons is discussed.     

The incorporation and characterization of powdery mildew resistance from Aegilops longissima in common wheat (T. aestivum L.)

Summary In the progeny of a hybrid between monotelosomic line 3B of Chinese Spring wheat and Chinese Spring — Aegilops longissima ditelosomic addition line G a cytologically stable strain was selected consisting of 20 wheat chromosome pairs, one pair of telosomic chromosome 3BL and one pair of telosomic longissima chromosome G. Inoculating Chinese Spring — Aegilops longissima addition and substitution lines with ten different powdery mildew isolates, partial resistance was observed. The infection grade as well as the number of spores/cm² leaf area were significantly reduced.     

Two-dimensional 1H NMR study of two cyclobutane type photodimers of thymidylyl-(3′→5′)-thymidine

2D NMR spectroscopy and J coupling constant analysis are applied to resolve the structure of two photoproducts of thymidylyl-(35)-thymidine. These products are cyclobutane type thymine dimers possessing the cis-syn (the predominant one) and trans-syn geometry. The cis-syn is formed in an ANTI-ANTI conformation about the N-glycosyl linkages and resembles the normal base-stacked configuration. The glycosidic conformation in solution of the 5 terminal fragment differs from the crystal in which the less common SYN conformation is observed. In this isomer only the sugar pucker of the 3 terminal fragment is changed substantially with respect to the dinucleotide. The trans-syn isomer is formed in a SYN-ANTI glycosidic conformation. In this isomer the sugar puckers of both deoxyribose rings are affected and a preference for a pure 2-endo conformation is observed.Abbreviations dTpdT 2-deoxythymidylyl-(35)-2-deoxythymidine - dTp[]dT cyclobutane type photodimers of dTpdT - dTp- and dTp[]- their 5' terminal fragments (fragment A) - -pdT and-[]pdT their 3 terminal fragments (fragment B) - RP-HPLC reversed-phase high-performance liquid chromatography - COSY two-dimensional correlated spectroscopy - 2D NOE two-dimensional nuclear Overhauser spectroscopy     

Energy conservation in whole cells of the methylotrophic bacterium Methylophilus methylotrophus

Respiratory chain phosphorylation has been investigated in the methylotrophic bacterium Methylophilus methylotrophus following the addition of oxidisable substrates to aerobic, whole cell suspensions. Initial-rate experiments showed that ATP synthesis occurred at the overall expense of AMP and inorganic phosphate via the sequential action of the ATP phosphohydrolase and adenylate kinase; some of the nascent ATP was rapidly used to synthesis nonadenine nucleoside triphosphates. After being corrected for ATP turnover, Pi/O quotients of 0.46 to 0.54, 0.77 and 1.37 nmol/ng-atom O were obtained for the oxidation of methanol dehydrogenase-linked substrates (methanol, ethanol and acetaldehyde), duroquinol and formate (NAD⁺-linked) respectively. These values were proportional to the H⁺/O and/or K⁺/O quotients exhibited by these substrates, and yielded an average H⁺/ATP (H⁺/Pi) quotient of 4.2 ng-ion H⁺/nmol. Steady-state experiments showed that the extent of cellular energisation varied with the respiration rate but was always in the order methanol > duroquinol > acetaldehyde, thus indicating that under these longer-term conditions methanol was completely oxidised to yield PQQH₂ and 2NAD(P)H. These results are discussed in terms of the various reactions which lead to the generation or utilisation of the protonmotive force in this organism.Abbreviations FCCP carbonylcyanide p-trifluoromethyxyphenyl-hydrazone - bulk phase, transmembrane electrochemical potential difference of protons ( ) - pH bulk phase, transmembrane pH difference (pH_in–pH_out) - bulk phase, transmembrane electrical potential difference (_in - _out) - [P] concentration of anhydride phosphate bonds in adenine nucleotides (2[ATP]+[ADP]) - FPLC fast protein liquid chromatography - PQQ pyrroloquinoline quinone - Gp phosphorylation potential     

Substitutions of the Conserved Thr42 Increased the Roles of the ε-Subunit of Maize CF1 as CF1 Inhibitor and Proton Gate

The conserved residue Thr42 of -subunit of the chloroplast ATP synthase of maize (Zea mays L.) was substituted with Cys, Arg, and Ile, respectively, through site-directed mutagenesis. The over-expressed and refolded -proteins were purified by chromatography on DEAE-cellulose and FPLC on mono-Q column, which were as biologically active (inhibiting Ca²⁺-ATPase activity and blocking proton gate) as the native subunit isolated from chloroplasts. The T42C and T42R showed higher inhibitory activities on the soluble CF₁(–) Ca²⁺-ATPase than the WT. The T42I inhibited the Ca²⁺-ATPase activity of soluble CF₁ and restored photophosphorylation activity of membrane-bound CF₁ deficient in the most efficiently. Far-ultraviolet CD spectra showed that the portions of -helix and -sheet structures of the three mutants were somewhat different from WT. Thus the conserved residue Thr42 may be important for maintaining the structure and function of the -subunit and the basic functions of the -subunit as far as an inhibitor of Ca²⁺-ATPase and the proton gate are related.     

The influence of lactation products on the temporal expression of histo-blood group antigens in the intestines of suckling pigs: lectin histochemical and immunohistochemical analysis

Summary Lectins and carbohydrate-specific monoclonal antibodies were used as cytochemical probes to investigate the possible influence of lactation products on the expression of intestinal membrane and secretory glycoconjugates in suckling piglets. Two different lactational regimes were compared; the first involved normal rearing of piglets for 8 weeks on a single dam and the second involved repeated cross-fostering of littermates onto recently farrowed sows, thereby restricting them to early milk. Five histo-blood group phenotypes were recognized within the piglet population: two immature phenotypes, O immature or Oi and A immature or Ai, and three mature forms, O, A and -. Under the normal suckling regime the transition from immature to mature OA phenotypes was evident at the fifth weekpost partum. However, in the repeatedly cross-fostered piglets this transition was evident much earlier at 3 weekspost partum. It is suggested that qualitative or quantitative variations in milk composition during the sow's lactation may significantly influence the expression of intestinal histo-blood group antigens in her suckling young.Abbreviations GalNac N-acetylgalactosamine - Gal Galactose - GlcNac N-acetylglucosamine     

The taxonomic significance of the trunk limbs of the chydoridae (Cladocera)

Summary The differences in the structure of the trunk limbs allow to outline three sections of Chydoridae (see table I and fig. 1), coinciding with the sections distinguished according to the structure of the head pores.

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Chydoridae (Cladocera)

Chydoridae (. ), , .

     

Genetic analysis of brown planthopper resistance in twenty varieties of rice,Oryza saliva L.

Summary The inheritance of resistance to brown planthopper, Nilaparvata lugens (Stol.), of 20 rice cultivars was studied. Single dominant genes that are allelic to Bph 3 condition the resistance in cultivars Ptb 19, Gangala (Acc. 7733), Gangala (Acc. 15207), Horana Mawee, Kuruhondarwala, Mudu Kiriyal and Muthumanikam. Single recessive genes that are allelic to bph 4 govern the resistance in cultivars Gambada Samba, Heenhoranamawee, Hotel Samba, Kahata Samba, Kalukuruwee, Lekam Samba, Senawee, Sulai, Thirissa and Vellai Illankali. The resistance in Ptb 33, Sudu Hondarwala, and Sinna Sivappu is governed by one dominant and one recessive gene which segregate independently of each other. The dominant resistance genes in these cultivars appear allelic to either Bph 1 or Bph 3. Similarly, the recessive genes in these cultivars seem allelic to either bph 2 or bph 4. Further investigations are needed to conclusively determine the allelic relationships of resistance genes in Ptb 33, Sudu Hondarwala and Sinna Sivappu.     

Effects of drought on the yellowing status and the dynamics of mineral elements in the xylem sap of declining spruce (Picea abies L.)

In order to test the effects of drought on the occurrence of spruce yellowing, in the Vosges Mountains (northeastern France), the soil of a plot of a 30-year-old spruce stand was protected from throughfall input by a roof for two months during the summer. The degree of yellowing of the trees from the dry and control plots was measured before and after the experiment. Sap flow and sap concentrations were measured in the control plot during the whole of the growing season, and in the dry plot during the drought period. Drought brought about an increase of needle yellowing linked to a reduction in Mg uptake. A decrease in sap concentration of concentration of Ca, Mg and K occurred in the dry plot as compared with the control plot at the end of the drought period. It is concluded that climatic stress could have been the triggering factor of spruce yellowing in the Vosges during the eighties.     

The aerobic nitrogen-fixingSynechococcus RF-1 containing uncommon polyglucan granules and multiple forms of α-amylase

The aerobic nitrogen-fixing unicellular cyanobacteriumSynechococcus RF-1 (pcc 8801) contains numerous irregular polyglucan granules ranging in size from 0.1 to 0.4 m. These morphologically unusual polyglucan granules are not found in the sheathed nitrogen-fixing unicellular cyanobacteriumGloeothece RF-6 (pcc 8803). Two forms of -amylase, ethyleneglycolbis-(-aminoethyl ether)-N,N,N,N-tetraacetic acid (EGTA)-sensitive and EGTA-insensitive, were found in theSynechococcus RF-1. In addition to their EGTA sensitivity, the two forms of -amylase also differed in their reactive pH range and in their zymogram disc gel electrophoresis. Each form of -amylase was stable and constant in concentration through a diurnal light/dark cycle.     

One-bond carbon-proton coupling constants: Angular dependence in β-linked oligosaccharides

Summary The angular dependence of¹J_C,H in model compounds related to -linked oligosaccharides has been established by FPT INDO quantum chemical calculations. Values calculated for models of (1 1)-, (1 2)-, (1 3)- and (1 4)-linked disaccharides were compared, and the effect of the orientation of HO-2 elucidated. The angular dependence of¹J_C,H on the torsional angles ^H and ^H and the solvent dielectric constant (s) was characterized in the form:¹J_C,H = A cos2+B cos + C sin2 + D since + E + Fe. The¹J_C,H values, measured by DEPT methods for C-1-H-1 and C-X-H-X in cellobiose, cyclic trisaccharide and hexopyranoses were used to adjust the calculated angular dependences. Based on the occurrence of the conformers for agarobiose, neoagarobiose, mannobiose and methyl -xylobioside, the thermodynamically averaged <¹J_C,H > values were calculated. The results obtained (<¹J_C-1,H-1 > 162.4, <¹J_{C-4, H-4} > 147.6 Hz for methyl -xylobioside; <¹J_C-1,H-1 > 162.4 and <¹J_C-4,H-4] > 147.6 Hz for mannobiose; <¹J_C-1,H-1 > 162.8 Hz for neo agarobiose and <¹J_C-1,H-1 > 163.2 Hz for agarobiose) agree well with the experimental values of 162.7, 147.5, 160.4, 147.2, 160.9 and 165.7 Hz, respectively.     

A novel PH-CT-COSY methodology for measuring JPH coupling constants in unlabeled nucleic acids. Application to HIV-2 TAR RNA

A quantitative analysis of J_PH scalar couplings in nucleic acids is difficult due to small couplings to phosphorus, the extreme overlap of the sugar protons and the fast relaxation of the spins involved in the magnetization transfer. Here we present a new methodology that relies on heteronuclear Constant Time Correlation Spectroscopy (CT-COSY). The three vicinal ³J_PH3, ³J_PH5 and ³J_PH5 scalar couplings can be obtained by monitoring the intensity decay of the P_i-H3_{i – 1} peak as a function of the constant time T in a 2D correlation map. The advantage of the new method resides in the possibility of measuring the two ³J_PH5 and ³J_PH5 scalar couplings even in the presence of overlapped H5/H5 resonances, since the quantitative information is extracted from the intensity decay of the P-H3 peak. Moreover, the relaxation of the H3 proton is considerably slower than that of the H5/H5 geminal protons and the commonly populated conformations of the phosphate backbone are associated with large ³J_PH3 couplings and relatively small ³J_{PH5 / H5}. These two facts lead to optimal signal-to-noise ratio for the P-H3 correlation compared to the P-H5/H5 correlation.The heteronuclear CT-COSY experiment is suitable for oligonucleotides in the 10–15 kDa molecular mass range and has been applied to the 30mer HIV-2 TAR RNA. The methodology presented here can be used to measure P-H dipolar couplings (D_PH) as well. We will present qualitative results for the measurement of P-H_base and P-H2 dipolar couplings in the HIV-2 TAR RNA and will discuss the reasons that so far precluded the quantification of the D_PHs for the 30mer RNA.     

Hydrolysis of 2-substituted aryl and heteroaryl alkanoates by Candida rugosalipase

sThe hydrolysis of several esters catalyzed by lipase of Candida rugosa was used to analyse the interaction between the ester substrate and the active site and the geometry and steric restrictions of alk, ar and h subsites. Using 4-R-C H -CH(R)-COOEt and ethyl trans-cinnamate, the presence of a low electronic density zone in the ar pocket is described, the dimensions of the pocket produced by Phe-296 and Leu-297 in the alk subsite and the size of the h subsite are described.     

Formation of P1, P2-dinucleoside 5′-pyrophosphates under potentially prebiological conditions

Summary Organic pyrophosphates such as UppA and NAD are formed when a solution containing a nucleotide, a nucleoside 5-polyphosphate, Mg²⁺ and imidazole are allowed to dry out. We suggest that this synthesis may have occured concurrently with oligonucleotide formation.Abbreviations Im Imidazole - CDI 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride - EDTA ethylenediaminetetraacetic acid - A adenosine - U uridine - p_nA adenosine 5-poly-phosphate containing n phosphate residues - pU uridine 5-phosphate - AppA P₁,P₂-diadenosine 5-pyrophosphate - UppA P₁-(uridine 5)-P₂-(adenosine 5)-pyrophosphate - ImpA adenosine 5-phosphorimidazolide - NMN nicotinamide mononucleotide - NAD nicotinamide-adenine dinucleotide     

Limits of artificial selection under unbalanced mating systems

Summary The influence of unbalanced mating systems — factorial mating (FM) and random loss of families after a full diallel crossing (RS) — on the ultimate probability of gene fixation (u()) and the time required to fix or lose a gene (t()) are investigated. The average u() of these systems is smaller than that of random mating, and the range of u() for a given initial parental genotype combination is very large (close to one for most initial genotypic combinations). The average u() of different parental genotypic combinations of a given gene frequency are different. These systems accelerate the t().This article was written and prepared by U.S. Government employees on official time, and it is therefore in the public domain