title: PsTRXh1 and PsTRXh2 are both pea h-type thioredoxins with antagonistic behavior in redox imbalances.
abstract: Thioredoxins (TRXs) are small ubiquitous oxidoreductases involved in disulfide bond reduction of a large panel of target proteins. The most complex cluster in the family of plant TRXs is formed by h-type TRXs. In Arabidopsis (Arabidopsis thaliana), nine members of this subgroup were described, which are less well known than their plastidial counterparts. The functional study of type-h TRXs is difficult because of the high number of isoforms and their similar biochemical characteristics, thus raising the question whether they have specific or redundant functions. Type-h TRXs are involved in seed germination and self incompatibility in pollen-pistil interaction. Their function as antioxidants has recently been proposed, but further work is needed to clarify this function in plants. In this study, we describe two new h-type TRXs from pea (Pisum sativum; stated PsTRXh1 and PsTRXh2). By functional complementation of a yeast (Saccharomyces cerevisiae) trx1Delta trx2Delta double mutant, we demonstrate that PsTRXh1 is involved in the redox-imbalance control, possibly through its interaction with peroxiredoxins. In contrast, PsTRXh2 provokes a phenotype of hypersensitivity to hydrogen peroxide in the yeast mutant. Furthermore, we show differential gene expression and protein accumulation of the two isoforms, PsTRXh1 protein being abundantly detected in vascular tissue and flowers, whereas PsTRXh2 gene expression was hardly detectable. By comparison with previous data of additional PsTRXh isoforms, our results indicate specific functions for the pea h-type TRXs so far described.
authors.affiliation: Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, 18008 Granada, Spain. jose.traverso@isv.cnrs-gif.fr
authors.forename: José A
authors.initials: JA
authors.lastname: Traverso
authors.forename: Florence
authors.initials: F
authors.lastname: Vignols
authors.forename: Roland
authors.initials: R
authors.lastname: Cazalis
authors.forename: Amada
authors.initials: A
authors.lastname: Pulido
authors.forename: Mariam
authors.initials: M
authors.lastname: Sahrawy
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Cejudo
authors.forename: Yves
authors.initials: Y
authors.lastname: Meyer
authors.forename: Ana
authors.initials: A
authors.lastname: Chueca
mesh_terms: D000595:Amino Acid Sequence; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009154:Mutation; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D018532:Pisum sativum / Q000033:anatomy & histology / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D013879:Thioredoxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D013879:Thioredoxins