Arabidopsis thaliana plant defensin AtPDF1. 1 is involved in the plant response to biotic stress

• Published in: The New phytologist Vol. 187; no. 4; pp. 1075 - 1088
• Main Authors: De Coninck, Barbara M. A., Sels, Jan, Venmans, Esther, Thys, Warmes, Goderis, Inge J. W. M., Carrón, Delphine, Delauré, Stijn L., Cammue, Bruno P. A., De Bolle, Miguel F. C., Mathys, Janick
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing 01-09-2010
• Subjects: Antifungals; Fungi; Genes; Inoculation; Leaves; Pathogens; Plant diseases; Plants; Promoter regions; Transgenic plants
• ISSN: 0028-646X; 1469-8137

Previously, it was shown that the Arabidopsis thaliana plant defensins AtPDFI .1 (At1g75830) and AtPDFI .2a (At5g44420) exert in vitro antimicrobial properties and that their corresponding genes are expressed in seeds and induced in leaves upon pathogen attack, respectively. In this study, the expression profile of both AtPDFI. 1 and AtPDFI. 2a is analysed in wild-type plants upon different stress-related treatments and the effect of modulation of their expression in transgenic plants is examined in both host and nonhost resistance. AtPDFI. 1 , which was originally considered to be seed-specific, is demonstrated to be locally induced in leaves upon fungal attack and exhibits an expression profile distinct from that of AtPDFI. 2a, a gene frequently used as marker for the ethylene/jasmonate-mediated signaling pathway. Transgenic plants with modulated AtPDFI. 1 or AtPDFI. 2a gene expression show no altered phenotype upon Botrytis cinérea inoculation. However, constitutive overexpression oí AtPDFI. 1 in A. thaliana leads to a reduction in symptoms caused by the nonhost Cercospora beticola causing non-spreading spots on A. thaliana leaves. These results indicate that AtPDFI. 1 and AtPDFI. 2a clearly differ regarding their expression profile and functionality in planta. It emphasizes the additional level of complexity and fine-tuning within the highly redundant plant defensin genes in A.thaliana.