Structural and Functional analyses of Dehydrin8208;like proteins in the necrotrophic fungus Alternaria brassicicola

Ref ID: 18533

Author:

Stéphanie Pochon,
Sandrine Pigné,
Nelly Bataillé-Simoneau,
Marjorie Juchaux,
Emmanuel Jaspard,
Philippe
Simoneau,
Thomas Guillemette

Author address:

Research Institute Horticulture and Seed – UMR 1345 -Fungisem, Faculté des Sciences, 2 Bd Lavoisier, F-49045
ANGERS (France).
SFR QUASAV – IMAC Platform, 2 Bd Lavoisier, F-49045 ANGERS (France)
Research Institute Horticulture and

Full conference title:

11 th European Conference on Fungal Genetics

Abstract:

Dehydrins (DHN) are a protein subclass of Late Embryogenesis Abundant proteins (LEA) which, in plants, are
involved in the salt and hydric stress resistance. In fungi, dehydrin8208;like proteins have been identified in Tuber
borchii and Aspergillus fumigatus and a signature pattern has been described for these proteins (1,2). Using this
sequence motif, we have identified three DHN8208;encoding genes in the genome of the necrotrophic fungus
Alternaria brassicicola. Sequence analysis confirmed that they all shared the characteristic features of dehydrins:
high glycine, threonine and serine content, low cysteine and tryptophan content, high hydrophilicity, absence of
secondary structures and a high proportion of disordered amino acids. Measures of the expression levels of the
three DHN genes in conditions previously reported to induce fungal DHNs transcription (low temperature, salinity
and oxidative stress) revealed that they were all up regulated in these conditions. To study their subcellular
localization, dehydrin8208;like proteins were fused to eGfp at their carboxy8208;terminal end and expressed in A.
brassicicola under control of their own promoters. Fluorescent protein fusions showed that at least one dehydrin
was associated with peroxisomes. A functional analysis has been performed by the construction of knockout
mutants deficient for each DHN. Although none of the dehydrin8208;like mutants were found more susceptible to NaCl
than the WT strain, they were all characterized by a stronger susceptibility towards oxidative stress (menadione or
H2O2). A double8208;mutant strain exhibited reduced virulence on host leaves and decreased seed transmission rates
compared to the parental strain, indicating a role of DHNs in pathogenicity.
1. Abba, S., Ghignone, S. and Bonfante, P. (2006) A dehydration8208;inducible gene in the truffle Tuber borchii
identifies a novel group of dehydrins. BMC Genomics, 7, 398208;54.
2. Wong Sak Hoi J, Lamarre C, Beau R, Meneau I, Berepiki A, Barre A, Mellado E, Read ND, Latgí© JP. (2011) A novel
family of dehydrin8208;like proteins is involved in stress response in the human fungal pathogen Aspergillus fumigatus.
Mol Biol Cell., 11:18968208;906.

Abstract Number: PR8.54

Conference Year: 2012

Link to conference website: http://www.ecfg.info/images/Abstract_Book_Electronic.pdf

New link: NULL

Conference abstracts, posters & presentations

Showing 10 posts of 17325 posts found.

  • Title

    Author

    Year

    Number

    Poster