Analysis of Genetic Diversity at the arom Locus in Isolates of Pneumocystis carinii

ABSTRACT. The DNA sequences of a portion of the 5-enolpyruvyl shikimate phosphate synthase domain of the arom gene, encoding the pentafunctional AROM protein, were determined from isolates of Pneumocystis carinii from five mammalian host species (rat, human, ferret, rabbit and mouse). High levels of genetic divergence were found among P. carinii derived from different hosts species, 7–22% at the DNA sequence level, and 7–26% at the derived amino acid sequence level. Two separate and distinct sequences were isolated from infected ferret lungs. Low levels of divergence were seen in human-derived organisms.     

CHLOROPHYLL FORMATION IN ISOLATED PUMPKIN COTYLEDONS IN THE PRESENCE OF KINETIN AND CHLORAMPHENICOL

Investigations have been made on the changes in the levels ofprotochlorophyll, chlorophyll a and chlorophyll b in relationto the kinetin induced expansion of isolated pumpkin cotyledonsin the presence and absence of chloramphenicol. It has been shown that rise in pigment level keeps pace withexpansion growth of the cotyledons. Kinetin markedly promotes the synthesis of protochlorphyll withoutmuch affecting the rate of its photoreduction to chlorophyll. Chloramphenicol strongly inhibits the development of both chlorophylla and b. The inhibition seems to be due to its interferenceboth with the synthesis of protochlorophyll and its subsequentconversion to chlorophyll. The inhibitory effect of chloramphenicol on the formation ofchlorophyll a is greater than on that of chlorophyll b, suggestingthereby the probability of divergent pathways for the formationof the two chlorophylls. (Received December 21, 1966; )     

Enhancement in Growth and Yield of Wheat (Triticum aestivum L.) by Pre-sowing Chill Treatment to Grains

Pre-sowing chill treatments to grains of Wheat (Triticum aestivumL. cvs Kalyan sona and cv. 4530) induce enhancements in growth,tillering and yield. Further, levels of several biochemicalcomponents are also higher in the grains harvested from plantsgrown from chill-treated grains. This method applied in thelaboratory and on a farm scale, effective also in other plants,can be conveniently used for yield enhancement and improvementof seed quality. Triticum aestivumL., wheat, chill treatment