Allomones confer resistance to Musa cultivar Pisanglilin against infestation by Odoiporus longicollis [Oliver] and characterization of Allomones

In bioassay guided extraction of pseudostem powder of Pisanglilin by organic solvents we found the larvicidal activity in acetone extract, whose column chromatography by methanol-chloroform mixture separated the extract into 9-fractions, of which the 8th fraction showed larvicidal activity. Subfractionation of the active fraction by column chromatography resulted in the isolation of two larvicidal molecules [Stigmasterol-3-O-glucoside (SOG) and Sulfoquinovosyl diacylglycerol (SQDG)]. Yield of SOG was 0.002 % and SQDG was 0.005 % and both were highly toxic to O. longicollis larvae with LD50 of 0.40 and 0.378 ppm, respectively. Larvae fed these compounds stopped feeding on third day and died within one week. SOG inhibited the amylase and protease activity of gut and induced histolysis in the mid gut. While SQDG inhibited the leucine amino peptidase and trypsin like serine protease activities, which decreased the content of total free amino acids. Imbalance in the activities of aspartate amino transferase and alanine amino transferase disrupted the aminoacid metabolism and the compound inhibited the activity of tyrosinase (an enzyme involved in cuticle development). SQDG toxicity caused accumulation of 20-hydroxyecdysone, the active moulting hormone in the hemolymph. Simultaneous action of two allomones present in Pisanglilin effectively resisted the attack of endophytic larvae in the pseudostem and thereby conferred resistance against infestation by O.longicollis. Preliminary study by intrapseudostem injection of Pisanglilin extract in susceptible M.paradisiaca cultivar Kappa, gave complete protection to it from attack by this pest, under field condition.

Metabolic substrates alter attachment and differentiated functions of proximal tubule cell culture.

Proximal tubules cultured in vitro gradually lose their differentiated functions. Because standard culture media lacks several substrates important for renal proximal tubule oxidative metabolism, whether a mixture of substrates including butyrate, alanine, and lactate (BAL) would modify growth and/or differentiated function of proximal tubular cells in culture was examined. Tubules cultured in media supplemented with 2 mM butyrate, alanine, and lactate exhibited enhanced attachment but did not exhibit an altered growth rate. Higher levels of phosphoenolpyruvate carboxykinase and leucine-amino peptidase were sustained, although these activities were still diminished in comparison with that in fresh tubules. Sodium-dependent glucose uptake and dome formation--other reflections of epithelial cell differentiated function--also were enhanced. These studies demonstrate that the substrates used to culture proximal tubules can modify both their attachment and their manifestation of differentiated function in culture.

ALLOZYME INHERITANCE AND DIVERSITY IN SOUR CHERRY

Starch gel electrophoresis was employed to study inheritance and diversity of allozyme loci in a sour cherry (2n=4×=32) germplasm collection. Segregation data was collected for alcohol dehydrogenase (ADH), glucose phosphate isomerase (GPI), isocitrate dehydrogenase (IDH), leucine amino peptidase (LAP), malate dehydrogenase (MDH), peroxidase (PX) (cathodal activity), phosphoglucomutase (PGM), 6-phosphogluconic dehydrogenase (6-PGD), and shikimate dehydrogenase (s k d h).Data suggest that alleles can be assigned to many of the enzyme systems being studied: ADH, GPI, IDH, LAP, PGM, and 6-PGD. Most loci are diallelic and often exhibit the unbalanced heterozygous condition. MDH, PX, and 6-PGD are highly polymorphic. Progeny segregation data fit disomic inheritance models, indicating that sour cherry is an allotetraploid.