Pea embryonic tissues show common responses to the replication of a wide range of viruses

The response of pea embryonic tissues to the replication of a range of diff erent viruses was investigated using in situ hybridization to analyze chang es in the expression of two host genes, heat shock protein 70 (hsp70) and l ipoxygenase (lox1). Excised pea embryos were infected using microprojectile bombardment with a nonseed transmissible strain of Pea seed-borne mosaic p otyvirus, or with Pea early browning tobravirus (PEBV), White Clover mosaic potexvirus, or Beet curly top geminivirus. Collectively these examples rep resent families of viruses with differing genomic features, differing numbe rs 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 direc t inducer of these common responses or the induction is indirectly the resu lt of a generic feature of virus infection. By exploiting the bipartite nat ure of the PEBV genome, the coat protein gene and genes involved in vector transmission were excluded as potential inducers. (C) 2000 Academic Press.