Pathogenesis-related proteins in Brazilian wheat genotypes: protein induction and partial gene sequencing

Abstract

Leaves from 14 Brazilian genotypes of Triticum aestivum L. were treated with salicylic acid to induce pathogenesis-related (PR) proteins. Inter and intracellular extracts were then obtained and investigated through polyacrilamide gel electrophoresis. Seven bands were observed. Material related to two of them (of 40 and 24 kDa) occurred in intracellular spaces only. DNA from these same genotypes was then amplified through PCR using primers developed from three sequences encoding PR proteins, and compared with previously described sequences. The fragments presented homologies to PR groups 1, 3 (chitinases), and 5 (thaumatinlike). The PR3-like sequence also showed a site characteristic of PRs induced by ethylene and a portion without homology with previous sequences. No variation among genotypes were observed, either for protein extracts or DNA sequences.

Preliminary analysis of expressed sequences of genes in Genipa americana L. plant roots exposed to cadmium in nutrient solution

“…The PR proteins occur in a wide variety of plant species, whose induction usually follows the development of a local or systemic resistance after infection by a great number of pathogens (Freitas et al, 2003). The effect of Cd in plant species mimics the response of plants to pathogen attack, in that an increase in reactive oxygen species is observed, followed by reactions of secondary defenses (Schützendübel and Polle, 2002).…”

Molecular investigations of pathogenesis-related Bet v 1 homologues in Passiflora (Passifloraceae)

“…The major allergenic compound of the pollen of Betulaceae (Bet v 1) and related proteins (Bet v 1 homologues) belong to this class of substances, that has been classified as PR10. The genomic characterization and molecular structure of PRID have been performed by Breiteneder et al (1989), Faber et al (1996, Wen et al (1997), Friedl-Hajek et al (1999), Freitas, Koehler and Salzano (2003a, Freitas, Bonatto and Salzano (2003b) and (N.M. Scherer et al, in press). PRID biological function is still being debated, but at least some of them show ribonuclease activity (Moiseyev et al, 1994(Moiseyev et al, , 1997Bufe et al, 1996).…”