In this study it was aimed to investigate inducibility of secondary metabolism in Astragalus chrysochlorus by yeast extract which is known to cause the synthesis of defensive phenolic metabolites. Cell suspension cultures of Astragalus chrysochlorus responded to elicitor treatment (10 gl(-1) yeast extract) by increasing phenylalanine ammonia lyase (PAL E.C. 4.3.1.5) activity the key enzyme of p...

Etiolated hypocotyls of the resistant soybean (Glycine max [L.] Merr.) cultivar Harosoy 63 became susceptible to Phytophthora megasperma (Drechs.) f.sp. glycinea (Hildeb.) Kuan and Erwin race 1 after treatment with abscisic acid. Susceptibility was expressed by increases in lesion size and a major decrease in accumulation of the isoflavonoid phytoalexin, glyceollin. In untreated hypocotyls, act...

A cDNA clone for phenylalanine ammonia-lyase (PAL) induced in wounded sweet potato (Ipomoea batatas Lam.) root was obtained by immunoscreening a cDNA library. The protein produced in Escherichia coli cells containing the plasmid pPAL02 was indistinguishable from sweet potato PAL as judged by Ouchterlony double diffusion assays. The M(r) of its subunit was 77,000. The cells converted [(14)C]-l-p...

Wheat (Triticum aestivum L. cv Fremont) grown in hydroponic culture under 24-hour continuous irradiation at 560 to 580 micromoles per square meter per second from either metalhalide (MH), high pressure sodium (HPS), or low pressure sodium (LPS) lamps reached maturity in 70 days. Grain yields were similar under all three lamps, although LPS-grown plants lodged at maturity. Phenylalanine ammoni...

Given the essential role played by phenol metabolism in many resistance responses to different types of stress, the aim of the present work was to determine how different application rates of calcium may influence this metabolic process. Increased calcium in the nutrient solution in which tobacco plants were grown considerably reduced the foliar concentration of phenolic compounds. Calcium clea...