Swoboda I, Scheiner O, Kraft D, Breitenbach M, Heberle-Bors E, Vicente O
Institute of Microbiology and Genetics, University of Vienna, Vienna Biocenter, Austria.
Biochim Biophys Acta. 1994 Oct 18;1219(2):457-64. doi: 10.1016/0167-4781(94)90072-8.
Bet v I, the major pollen allergen of birch (Betula verrucosa), shows high sequence homology to a family of pathogenesis-related (PR) proteins that have recently been identified in several other plant species. We have used a pollen Bet v I cDNA clone and anti-Bet v I antibodies as probes to study the expression of Bet v I genes in birch cell suspension cultures under different experimental conditions. Induction of Bet v I-related proteins was detected in immunoblots of cell extracts upon co-cultivation with microbial pathogens. Northern analysis revealed the rapid induction of Bet v I transcripts in the presence of bacteria and fungi, but not by stress treatments (heat shock, metal ions) or by chemical elicitors. RNase protection experiments showed that the pathogen-inducible RNAs did not correspond to the pollen cDNA clone but most likely to the products of transcription of other members of the Bet v I gene family, sharing high sequence homology with the pollen-specific gene within the 5'-half of the coding region. We conclude that the Bet v I gene family of pollen allergens includes a subset of defense-related genes that are transcriptionally activated in the presence of microbial pathogens.
桦树（疣枝桦）的主要花粉过敏原Bet v I与最近在其他几种植物物种中鉴定出的一类病程相关（PR）蛋白具有高度的序列同源性。我们使用花粉Bet v I cDNA克隆和抗Bet v I抗体作为探针，研究了在不同实验条件下桦树细胞悬浮培养物中Bet v I基因的表达。在与微生物病原体共培养后，在细胞提取物的免疫印迹中检测到了Bet v I相关蛋白的诱导。Northern分析显示，在存在细菌和真菌的情况下，Bet v I转录本迅速被诱导，但在应激处理（热休克、金属离子）或化学激发子处理下则未被诱导。RNase保护实验表明，病原体诱导的RNA与花粉cDNA克隆不对应，而最有可能对应于Bet v I基因家族其他成员的转录产物，在编码区5'端的一半区域内与花粉特异性基因具有高度的序列同源性。我们得出结论，花粉过敏原的Bet v I基因家族包括一组与防御相关的基因，这些基因在微生物病原体存在时会被转录激活。
