The Nonspecific Lipid Transfer Protein AtLtpI-4 Is Involved in Suberin Formation of Arabidopsis thaliana Crown Galls.
Plant Physiol
; 172(3): 1911-1927, 2016 11.
Article
em En
| MEDLINE
| ID: mdl-27688623
ABSTRACT
Nonspecific lipid transfer proteins reversibly bind different types of lipid molecules in a hydrophobic cavity. They facilitate phospholipid transfer between membranes in vitro, play a role in cuticle and possibly in suberin formation, and might be involved in plant pathogen defense signaling. This study focuses on the role of the lipid transfer protein AtLTPI-4 in crown gall development. Arabidopsis (Arabidopsis thaliana) crown gall tumors, which develop upon infection with the virulent Agrobacterium tumefaciens strain C58, highly expressed AtLTPI-4 Crown galls of the atltpI-4 loss-of-function mutant were much smaller compared with those of wild-type plants. The gene expression pattern and localization of the protein to the plasma membrane pointed to a function of AtLTPI-4 in cell wall suberization. Since Arabidopsis crown galls are covered by a suberin-containing periderm instead of a cuticle, we analyzed the suberin composition of crown galls and found a reduction in the amounts of long-chain fatty acids (C180) in the atltpI-4 mutant. To demonstrate the impact of AtLtpI-4 on extracellular lipid composition, we expressed the protein in Arabidopsis epidermis cells. This led to a significant increase in the very-long-chain fatty acids C24 and C26 in the cuticular wax fraction. Homology modeling and lipid-protein-overlay assays showed that AtLtpI-4 protein can bind these very-long-chain fatty acids. Thus, AtLtpI-4 protein may facilitate the transfer of long-chain as well as very-long-chain fatty acids into the apoplast, depending on the cell type in which it is expressed. In crown galls, which endogenously express AtLtpI-4, it is involved in suberin formation.
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Coleções:
01-internacional
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MEDLINE
Assunto principal:
Tumores de Planta
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Proteínas de Transporte
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Arabidopsis
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Proteínas de Arabidopsis
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Proteínas de Transferência de Fosfolipídeos
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Lipídeos
Idioma:
En
Revista:
Plant Physiol
Ano de publicação:
2016
Tipo de documento:
Article