Isolation of regulatory DNA regions related to differentiation of nematode feeding structures in Arabidopsis thaliana

In order to identify promoter sequences related to the differentiation of nematode feeding sites, a collection of Arabidopsis thaliana plants transformed with a promoterless gus-construct was screened by infection with the root-parasitic nematode Heterodera schachtii. Line # 884 showed gus activity in nematode feeding structures (NFS), leaf hydathodes, and stipules. The most frequent gus activity in NFS was detected 7 days after infection. DNA gel blot analysis indicated a single copy of the T-DNA in line #884. Using inverse PCR, a 963 bp fragment 5' to the T-DNA was isolated and used to screen a genomic library of A, thaliana. A 4.2 kb fragment containing the insertion site was isolated. Sh fusion constructs consisting of different sequences of the isolated genomic clone and the gus gene was transformed into Arabidopsis plants. In this way it was possible to identify regulatory regions which are essential to gus expression in NFS. (C) 1998 Academic Press.