Genetics and Mechanism of Resistance to Meloidogyne arenaria in Peanut Germplasm

Segregation of resistance to Meloidogyne arenaria in six BC₅F₂ peanut breeding populations was examined in greenhouse tests. Chi-square analysis indicated that segregation of resistance was consistent with resistance being conditioned by a single gene in three breeding populations (TP259-3, TP262-3, and TP271-2), whereas two resistance genes may be present in the breeding populations TP259-2, TP263-2, and TP268-3. Nematode development in clonally propagated lines of resistant individuals of TP262-3 and TP263-2 was compared to that of the susceptible cultivar Florunner. Juvenile nematodes readily penetrated roots of all peanut genotypes, but rate of development was slower (P = 0.05) in the resistant genotypes than in Florunner. Host cell necrosis indicative of a hypersensitive response was not consistently observed in resistant genotypes of either population. Three RFLP loci linked to resistance at distances of 4.2 to 11.0 centiMorgans were identified. Resistant and susceptible alleles for RFLP loci R2430E and R2545E were quite distinct and are useful for identifying individuals homozygous for resistance in segregating populations.     

Implicit associations with social status: the effects of relationship involvement

The study tested the proposition that relationship involvement influences the implicit responses of women to high- and low-status professions. It was hypothesized that when a high-involvement context was primed, women would have more positive implicit associations with high-status occupations than when a low-involvement context was primed. In contrast, when a high-involvement context was primed, women would have more negative associations with low-status occupations than when a low-involvement context was primed. To test the hypothesis, 123 female participants received a high or low relationship involvement prime. Then the participants completed a single category implicit associations test designed to measure the participants' associations with either high- or low-status occupations. As predicted, the relationship involvement prime influenced the positivity of associations made with high- and low-status occupations. The study pointed to the possibility that persons possess evolutionary-based implicit associations.     

Cortinarius sarcoflammeus sp. nov, a new species of subgenus Dermocybe (Agaricales) growing in Sphagnum bogs

 Cortinarius sarcoflammeus is proposed as a new species belonging to subgenus Dermocybe, on the basis of its morphological, chemical and ecological characters. The strong red-orange colour of the context and stipe base, large spores, sphagnicolous habitat and high dermorubin content are characteristic for the new species. Holotypes of C. huronensis and C. huronensis var. olivaceus have been examined for comparison, and their differences discussed. Photographs and line drawings of C. sarcoflammeus are added. Received February 13, 2001 Accepted March 23, 2001     

Phosphoenzyme conformational states and nucleotide-binding site hydrophobicity following thiol modification of the Ca2+-ATPase of sarcoplasmic reticulum from skeletal muscle

Enhanced fluorescence of the ATP analogue 2',3'-O-(2,4,6-trinitrocyclohexyldienylidine)adenosine 5'-triphosphate (TNP-ATP), bound to the Ca2+-ATPase of skeletal muscle sarcoplasmic reticulum, is closely related to phosphoenzyme levels (Bishop, J. E., Johnson, J. D., and Berman, M. C. (1984) J. Biol. Chem. 259, 15163-15171) and has an emission maximum consistent with decreased polarity of the TNP-ATP-binding site. The phosphoenzyme conformation responsible for increased nucleotide-binding site hydrophobicity has been studied by redistribution of phosphoenzyme intermediates following specific thiol group modification. N-Ethylmaleimide, in the presence of 50 microM Ca2+, 1 mM adenyl-5'-yl imidodiphosphate, pH 7.0, at 25 degrees C for 30 min, selectively modified the SH group essential for phosphoenzyme decomposition, which resulted in decreased ATPase activity, Ca2+ uptake, and a decrease in ATP-induced TNP-ATP fluorescence. Phosphorylated (Ca2+, Mg2+)-ATPase levels from [gamma-32P] ATP remained relatively unaffected (3.1 nmol/mg), but the ADP-insensitive fraction decreased from 56 to 15%. Phosphoenzyme levels from 32Pi were also decreased to the same extent as turnover, with equivalent loss of Pi-induced TNP-ATP fluorescence. The E1 to E2 transition, as monitored by the change in intrinsic tryptophan fluorescence, was unaffected. Modification of thiol groups of unknown function did not modify turnover-induced TNP-ATP fluorescence. It is concluded that the ADP-insensitive phosphoenzyme, E2-P, is responsible for enhanced TNP-ATP fluorescence. This suggests that the conformational transition, 2Ca2+outE1 approximately P----2Ca2+inE2-P, is associated with altered properties of the noncatalytic, or regulatory, nucleotide-binding site.     

Dependence on blood acetate concentration of the metabolic effects of ethanol in perfused rat liver

Unprotected oligonucleotides and oligodeoxynucleotides terminated with an unhindered 5'-phosphate group react with nucleoside 5'- phosphorimidazolides in aqueous solution to give 'capped' pyrophosphates in at least 70% yield. If adenosine 5'- phosphorimidazolide is used as a substrate in the reaction, ligase intermediates are obtained as products.     

Fatty acid composition and content of individual lipid fractions in adipose and muscle tissue of albino rats with alloxan diabetes

A study was made of the fatty acid composition and the content of triglycerides, phospholipids and nonesterified fatty acids (NFA) in adipose and muscle tissues of rats with alloxan diabetes. The concentration of NFA in alloxan diabetes was found to be considerably reduced in both adipose and muscle tissues. Meanwhile the content of NFA and phospholipids did not experience any substantial changes. The fatty acid composition of triglycerides of the tissues under study was characterized by considerable alterations under diabetes.     

A copper-containing protein that inhibits nitrite reductase from Pseudomonas aeruginosa

A non-blue copper-containing glycoprotein was isolated from Pseudomonas aeruginosa. The protein has a molecular mass of 10 kDa and contains 1 atom of EPR-detectable type II copper. The protein inhibits oxidation of both azurin and cytochrome c-551 catalyzed by nitrite reductase from Ps. aeruginosa. Thus, it may be considered as an endogenous inhibitor of nitrite reductase.