Lupinus albus L. Pathogenesis-Related Proteins That Show Similarity to PR-10 Proteins

Abstract

, apt 31 O, Santarém, Portugal (M.P.P.); and Instituto Superior d e Agronomia, 1399 Lisboa Codex, Portugal (C.P.P.R.)We describe a group of three acidic proteins, pathogenesisrelated (PR)-pl6.5a, PR-p16.5b, and PR-pl6.5c, that accumulate in the leaves of Lupinus albus L. cv Rio Maior plants when infected with the fungus Colletotrichum gloeosporioides Penz. These proteins co-migrate in sodium dodecyl sulfate-polyacrylamide gels as a single band of 16.5 kD, behaving as charge isomers, and are related to several members of the defense-related PR-10 protein family. Localization of the proteins was investigated by techniques of tissue printing and immunogold electron microscopy; they are predominantly associated with the vascular system and are localized extracellularly. The accumulation of PR-pl6.5a, PR-p16.5b, and PR-~1 6 . 5~ also seems to be induced by cucumber mosaic virus and by two forms of abiotic stress, salicylic acid and ultraviolet, suggesting a general defense role for these proteins.

Proteome Analysis. Novel Proteins Identified at the Peribacteroid Membrane from Lotus japonicus Root Nodules

“…The PR-4 family is formed by small proteins with a signal peptide for extracellular targeting and with similarity to wound-inducible proteins (win; Linthorst et al, 1991). The PR-10 proteins have ribonuclease activity (Bantignies et al, 2000) and have also been localized extracellularly (Pinto and Ricardo, 1995). The observed PR-10 homolog is similar to MtPR10-1 that is constitutively expressed in roots of M. truncatula and does not respond during nodulation, but is pathogen inducible in leaves .…”

The Lupinus albus class-III chitinase gene, IF3 , is constitutively expressed in vegetative organs and developing seeds

“…6D). The PR-10 proteins were previously shown to be induced after infection of L. albus with C. gloeosporioides (Pinto and Ricardo 1995).…”

Immunohisto- and cytochemical localization of PR-10 proteins induced by heavy metals in lupine roots

“…The intracellular localization of PR-10 proteins has been confirmed by many investigators, but in those studies a biochemical approach was applied (Qiaojuan et al 2008;Saraste et al 1990;Sikorski 1997) and there is very little data concerning cytochemical localization of PR-proteins. For example, electron microscopic observations of immunogold-labeled leaves have revealed the localization of PR-p16.5 a, b and c proteins in Lupinus albus infected by Collototrichum gloeosporioides (Pinto and Ricardo 1995). Gold particles were predominantly localized in the cell wall, although a few gold particles could be found in the cytoplasm, so the cytoplasmatic localization of PR (L1-L6) proteins presented in our experiments is only partly in line with the results of PR-p16.5 distribution.…”

“…Furthermore, members of the PR-10 group share several conserved features, including a lack of signal peptides and hydrophobic helices, acidic pI values of 4.5-6.5, and a high resistance to protease activity (Bantignies et al 2000;Walter et al 1990), and their glycine residues are important to the conformation of the highly conserved region called the glycine-rich P-loop (Saraste et al 1990;Sikorski et al 1999). Most PR-10 proteins are classified as intracellular proteins (Qiaojuan et al 2008;van Loon et al 1994); however, several authors point to their extracellular localization (Pinto and Ricardo 1995;Tamás et al 1997). In our previous study, PR-10 proteins induced by lead ions in lupine seedlings were detected using a tissue printing method (Przymusiński et al 2001).…”