2 MEMBERS OF THE BET-V-1 GENE FAMILY ENCODING BIRCH PATHOGENESIS-RELATED PROTEINS DISPLAY DIFFERENT PATTERNS OF ROOT EXPRESSION AND WOUND-INDUCIBILITY

Bet v 1-SC genes constitute a subset of a multigene family in birch (B etula pendula Roth) that includes the gene for the major pollen allerg en and encode proteins belonging to a new family of intracellular path ogenesis-related proteins. We have investigated the expression in birc h roots of the Bet v I-SCI and Bet v I-SC3 genes by northern and rever se-transcription-polymerase chain reaction analyses. Only Bet v I-SC3 was found to be highly expressed in roots under basal conditions but t his gene was not wound-inducible. Conversely the expression of the Bet v I-SCI gene was markedly transiently induced 8 to 9 h after the stre ss. Immunoblotting with polyclonal antiserum raised against the major birch pollen allergen confirmed that Bet v 1-related polypeptides are present in root extracts. This first report of Bet v I-SC gene express ion and wound-inducibility in birch roots suggests a possible function of proteins encoded by these genes in plant defense and/or root organ ogenesis.