Plant Defensin type 1 (PDF1): protein promiscuity and expression variation within the Arabidopsis genus shed light on zinc tolerance acquisition in Arabidopsis halleri

• Published in: The New phytologist Vol. 200; no. 3; pp. 820 - 833
• Main Authors: Shahzad, Zaigham, Ranwez, Vincent, Fizames, Cécile, Marquès, Laurence, Martret, Bénédicte, Alassimone, Julien, Godé, Cécile, Lacombe, Eric, Castillo, Teddy, Saumitou‐Laprade, Pierre, Berthomieu, Pierre, Gosti, Françoise
• Format: Journal Article
• Language: English
• Published: England New Phytologist Trust 01.11.2013; Wiley Subscription Services, Inc; Wiley
• Subjects: Adaptation, Physiological - genetics; Amino Acid Sequence; Antifungal activity; Antifungals; Arabidopsis; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis genus; Arabidopsis halleri; Arabidopsis Proteins - genetics; Arabidopsis Proteins - isolation & purification; Arabidopsis Proteins - metabolism; Arabidopsis Proteins - pharmacology; Bioactive compounds; biotic and abiotic stresses; comparative genomics; Defensins; Defensins - genetics; Defensins - metabolism; Disease Resistance - genetics; Evolution; Evolution, Molecular; Evolutionary genetics; Functionals; Fungicides; Fusarium - drug effects; Fusarium oxysporum; gene duplication; Gene Expression; Gene Expression Regulation, Plant; Genes; Genes, Plant; Genetic loci; Genome, Plant; Genomes; Genomics; Heavy metals; Life Sciences; Molecular Sequence Data; orthologues; paralogues; Plant Defensin type 1; Plants; Pollution tolerance; Properties; Proteins; Stress, Physiological - genetics; Transcription; Vegetal Biology; Yeasts; Zinc; zinc (Zn) tolerance; Zinc - metabolism; orthologues; Arabidopsis genus; paralogues; gene duplication; Plant Defensin type 1; Arabidopsis halleri; zinc (Zn) tolerance; biotic and abiotic stresses; comparative genomics
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.12396

Plant defensins are recognized for their antifungal properties. However, a few type 1 defensins (PDF1s) were identified for their cellular zinc (Zn) tolerance properties after a study of the metal extremophile Arabidopsis halleri. In order to investigate whether different paralogues would display specialized functions, the A. halleri PDF1 family was characterized at the functional and genomic levels. Eleven PDF1s were isolated from A. halleri. Their ability to provide Zn tolerance in yeast cells, their activity against Fusarium oxysporum f. sp. melonii, and their level of expression in planta were compared with those of the seven A. thaliana PDF1s. The genomic organization of the PDF1 family was comparatively analysed within the Arabidopsis genus. AhPDF1s and AtPDF1s were able to confer Zn tolerance and AhPDF1s also displayed antifungal activity. PDF1 transcripts were constitutively more abundant in A. halleri than in A. thaliana. Within the Arabidopsis genus, the PDF1 family is evolutionarily dynamic, in terms of gain and loss of gene copy. Arabidopsis halleri PDF1s display no superior abilities to provide Zn tolerance. A constitutive increase in AhPDF1 transcript accumulation is proposed to be an evolutionary innovation co-opting the promiscuous PDF1 protein for its contribution to Zn tolerance in A. halleri.