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Differential gene expression in nematode‐induced feeding structures of transgenic plants harbouring promoter— gus A fusion constructs
Author(s) -
Goddijn Oscar J.M.,
Lindsey Keith,
Lee Fréderique M.,
Klap Joke C.,
Sijmons Peter C.
Publication year - 1993
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1993.04050863.x
Subject(s) - heterodera schachtii , biology , arabidopsis , gene , chimeric gene , transgene , meloidogyne incognita , gene expression , beta glucuronidase , promoter , gus reporter system , microbiology and biotechnology , genetically modified crops , genetics , nematode , ecology , mutant
Sedentary plant‐parasitic nematodes are able to induce specialized feeding structures in the root system of their host plants by triggering a series of dramatic cellular responses. These changes presumably are accompanied by a reprogramming of gene expression. To monitor such changes, a variety of promoter— gus A fusion constructs were introduced into Arabidopsis and tobacco. Transgenic plants were analysed histochemically for GUS activity in the nematode feeding structures after infection with either Heterodera schachtii or Meloidogyne incognita . Promoters of the Cauliflower Mosaic Virus 35S gene, the bacterial nopaline synthase, rooting loci ( rol ) and T‐ cyt genes and the plant‐derived phenylalanine ammonia‐lyase I gene, which are highly active in non‐infected roots, were all downregulated in the feeding structures as indicated by the strong decrease of GUS activity inside these structures. Less stringent down‐regulation was observed with chimeric gus A fusion constructs harbouring truncated rol B and rol C promoter sequences. Similar observations were made with transgenic Arabidopsis lines that carried randomly integrated promoterless gus A constructs to identify regulatory sequences in the plant genome. Most of the lines that were selected for expression in the root vascular cylinder demonstrated local down‐regulation in feeding structures after infection with H. schachtii . The reverse pattern of GUS activity, a blue feeding structure amidst unstained root cells, was also found in several lines. However, GUS activity that was entirely specific for the feeding structures was not observed. Our data show that the expression of a large number of genes is influenced during the development of the nematode feeding structures.