The response of pea embryonic tissues to the replication of a range of different viruses was investigated using in situ hybridization to analyze changes in the expression of two host genes, heat shock protein 70 (hsp70) and lipoxygenase (lox1). Excised pea embryos were infected using microprojectile bombardment with a nonseed transmissible strain of Pea seed-borne mosaic potyvirus, or with Pea early browning tobravirus (PEBV), White Clover mosaic potexvirus, or Beet curly top geminivirus. Collectively, these examples represent families of viruses with differing genomic features, differing numbers of genomic components and differing replication strategies. In all cases, there was an induction of hsp70 associated with virus replication and, in most cases, a downregulation of lox1. Hence, either each virus has a direct inducer of these common responses or the induction is indirectly the result of a generic feature of virus infection. By exploiting the bipartite nature of the PEBV genome, the coat protein gene and genes involved in vector transmission were excluded as potential inducers.
Copyright 2000 Academic Press.