Mechanism of resistance in cowpea to the root-knot nematode, Meloidogyne incognita Race 1: II: De Novo Synthesis of phenylalanine ammonia lyase (E.C. 4.3.1.5.) Sirohi Anil, Dasgupta D.R. Division of Nematology Indian Agricultural Research Institute, New Delhi-110 012. Abstract The evidence for nematode elicited de novo synthesis of macromolecules. PAL, protein and RNA, during post-infection period was sought through ACTD treatment by incorporation of radiolabelled PAL substrate, leucine and uridine respectively in Pusa Do Fasli and C-152 compatible and incompatible cowpea cultivars under inoculated and uninoculated conditions. ACTD treatment resulted in cessation of radiochemical incorporation into PAL reaction product (trans-cinnamic acid), protein and RNA, implying that the de novo synthesis of new PAL, protein and RNA species were totally inhibited in ACTD treated tissues, especially in inoculated C-152. Comparative data on gel electrophoresis of:PAL and it's treatment with radiolabelled substrate in inoculated. ACTD treated and untreated root samples indicated de novo synthesis of PAL isozyme in C-152 in response to nematode mediated gene activation at transcriptional level. From the investigation it can be said that interaction between root-knot nematode, Meloidogyne incognita and it's host results in derepression of novel genes, subsequently leading to the de novo synthesis of RNA and protem molecules under the influence of elicitors released by the parasite. Top Key words Phenylalanine ammonia lyase (PAL), cowpea, Meloidogyne incognita, de novo synthesis, protein, RNA, isozyme, ACTD, resistance. Top |