Premium
Local expression of enzymatically active class I β‐1, 3‐glucanase enhances symptoms of TMV infection in tobacco
Author(s) -
Bucher Gregor L.,
Tarina Corina,
Heinlein Manfred,
Di Serio Francesco,
Meins Fred,
Iglesias Victor Alejandro
Publication year - 2001
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.2001.01181.x
Subject(s) - callose , tobacco mosaic virus , plasmodesma , virus , tobamovirus , biology , virology , hypersensitive response , mutant , cell , cell wall , microbiology and biotechnology , gene , biochemistry , plant disease resistance
Summary Mutant tobacco plants deficient for class I β‐1,3‐glucanase (GLU I) are decreased in their susceptibility to virus infection. This is correlated with delayed virus spread, a reduction in the size exclusion limit of plasmodesmata and increased cell‐wall deposition of the β‐1,3‐glucan callose. To further investigate a role of GLU I during cell‐to‐cell movement of virus infection, we inserted the GLU I coding sequence into TMV for overexpression in infected cells. Compared with the size of local lesions produced on plants infected with virus expressing either an enzymatically inactive GLU I or a frameshift mutant of the gene, the size of local lesions caused by infection with virus expressing active GLU I was consistently increased. Viruses expressing antisense GLU I constructs led to lesions of decreased size. Similar effects were obtained for virus spread using plants grown at 32°C to block the hypersensitive response. Together, these results indicate that enzymatically active GLU I expressed in cells containing replicating virus can increase cell‐to‐cell movement of virus. This supports the view that GLU I induced locally during infection helps to promote cell‐to‐cell movement of virus by hydrolyzing callose. Moreover, our results provide the first direct evidence that a biological function of a plant β‐1,3‐glucanase depends on its catalytic activity.