The herbicide glyphosate, N-(phosphonomethyl)glycine, induced phenylalanine ammonia-lyase (PAL) activity in the roots of dark-grown maize seedlings. This enzyme induction was shown to precede glyphosate-reduced fresh weight gain in the roots by 24--48 h. Feeding aromatic amino acids with glyphosate further inhibited growth while slightly lowering glyphosate-enhanced PAL activity. Soluble protei...

Pea (Pisum sativum L. cv Alcan) endocarp tissue challenged with an incompatible fungal pathogen, Fusarium solani f. sp. phaseoli or fungal elicitors results in the induction of pathogenesis-related (PR) genes and the accumulation of pisatin, a phytoalexin. Essentially the same response occurs in pea tissue exposed to DNA-specific agents that crosslink or intercalate DNA. In this study, the effe...

Glyphosate showed a remarkable effect inducing the change of flower symmetry from the actinomorphic to the zygomorphic type in Petunia hybrida. Glyphosate [N-(phosphonomethyl)glycine] reduced the anthocyanin content and showed a weak inhibitory effect against phenylalanine ammonia-lyase (PAL) activity. L-2-Aminooxy-3-phenylpropionic acid (APA), an inhibitor of PAL activity, reduced the anthocya...

The bacterial spot of tomato, caused by Xanthomonas spp., is a very important disease, especially in the hot and humid periods of the year. The chemical control of the disease has not been very effective for a number of reasons. This study aimed to evaluate, under greenhouse conditions, the efficacy of leaf-spraying chemicals (acibenzolar-S-methyl (ASM) (0.025 g.L(-1)), fluazinam (0.25 g.L(-1))...

Acrylic acids and alanines substituted with heteroaryl groups at the beta-position were synthesized and spectroscopically characterized (UV, HRMS, (1)H NMR, and (13)C NMR spectroscopy). The heteroaryl groups were furanyl, thiophenyl, benzofuranyl, and benzothiophenyl and contained the alanyl side chains either at the 2- or 3-positions. While the former are good substrates for phenylalanine ammo...

The molecular mechanism of enzyme (phenylalanine ammonia-lyase; EC 4.3.1.5) formation mediated by phytochrome in mustard seedlings was investigated by labeling the enzyme with deuterium followed by high resolution CsCl density gradient analysis. A favorable relationship between induced rise of activity and turnover of this short-lived enzyme (half-life 3-4 hr) was achieved by labeling pre-irrad...

Poplar (Populus tremula x alba) trees (clone INRA 717-1-B4) were cultivated for 1 month in phytotronic chambers with two different levels of ozone (60 and 120 nL L(-1)). Foliar activities of shikimate dehydrogenase (EC 1.1.1.25), phenylalanine ammonia lyase (EC 4.3.1.5), and cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.195) were compared with control levels. In addition, we examined lignin con...

Two Myb-related transcription factors, Myb305 and Myb340, are expressed specifically in flowers of Antirrhinum. The proteins are structurally very similar throughout their DNA binding domains, implying that they bind to common target motifs. This binding has been demonstrated experimentally. Myb305 has been shown to activate the gene encoding the first enzyme of phenylpropanoid metabolism, phen...

In a recent study of N-acylphosphatidylethanolamine (NAPE) metabolism in elicitor-treated tobacco (Nicotiana tabacum L.) cells, we identified a rapid release and accumulation of medium-chain N-acylethanolamines (NAEs) (e.g. N-myristoylethanolamine or NAE 14:0) and a compensatory decrease in cellular NAPE (K.D. Chapman, S. Tripathy, B. Venables, A.D. Desouza [1998] Plant Physiol 116: 1163-1168)....