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Abstract

Molecular characterization has been accomplished for five members of the peroxidase gene family in French bean. The most important of these, designated FBPI, corresponds to the isoform believed to be responsible for the apoplastic oxidative burst demonstrated by suspension-cultured cells in response to fungal elicitor. Identification was made by a complete match of six peptide sequences derived from the native protein to the translated sequence of the cDNA. Modelling of the surface structure in comparison with two other members of the peroxidase family did not reveal any unusual features which might account for its role in the oxidative burst. However, FBP1 when expressed in Pichia pastoris generated H2O2 using cysteine at pH 7.2, a specific property of the native protein when isolated from suspension-cultured cells. FBP1, together with other members of the family, were all induced in cell cultures by elicitor action although they all showed some expression in non-induced cultured cells. They were also expressed in all tissues examined with varying levels of intensity of detection in northern blots. This was confirmed by in situ hybridization and FBP1 expression was confirmed in tissues where it has been previously detected by immunolocalization methods. Assigning roles to individual peroxidases is an important goal and molecular identification of the oxidative burst peroxidase allows further exploration of the relative roles of the different systems involved in generating reactive oxygen species.

Genotype-Specific Growth and Proteomic Responses of Maize Toward Salt Stress

“…Class III peroxidases are enzymes secreted into the apoplast, where they oxidize (take electrons from donor molecules) phenolics, lignin precursors or other secondary metabolites. They also oxidize the growth hormone auxin, as well as other substrates ( Gaspar et al, 1982 ) and produce hydrogen peroxide ( Blee et al, 2001 ) and hydroxyl radicals ( Chen and Schopfer, 1999 ), two activated oxygen species involved in oxidative burst and in cell elongation. It is a multigenic complex family ( Hiraga, 2001 ), with roles in several plant developmental processes, including regulation of cell elongation, cell wall construction and defense against pathogens ( Mika et al, 2004 ; Passardi et al, 2004a ).…”

In silico comparison of genomic regions containing genes coding for enzymes and transcription factors for the phenylpropanoid pathway in Phaseolus vulgaris L. and Glycine max L. Merr

“…A number of enzymes are involved in the lignin/lignan branch of the phenylpropanoid pathway, in most cases, encoded by small gene families. Only few sequences for lignin peroxidases were available for common bean at the beginning of this study (Blee et al, 2001). The flavonoid/anthocyanin branch, which encodes the enzymes involved in the production of anthocyanins and proanthocyanidins (condensed tannins) associated with seed coat color as well as different flavonoids involved in nodulation and plant defense, is probably the most studied segment of the phenylpropanoid pathway.…”

Effects of feeding Clostera anachoreta on hydrogen peroxide accumulation and activities of peroxidase, catalase, and ascorbate peroxidase in Populus simonii × P. pyramidalis ‘Opera 8277’ leaves

“…The result indicated that the high activities of these enzymes resulted in the relatively low content of H 2 O 2 at 0.5 and 6 h. But the content of H 2 O 2 and the activities of these enzymes were all higher than control at three time points. Though POD has also been shown to efficiently produce H 2 O 2 (Blee et al 2001;Bolwell et al 2002), in poplar plants after herbivory damage it mainly The content of H 2 O 2 in herbivore-wounded leaves (hw) after DPI treatment. The contents in control leaves (ck), herbivorewounded leaves (hw), leaves treated only by DPI, and herbivorewounded leaves after DPI treatment (hw ?…”