Peroxiredoxin genes of Lotus japonicus: expression analysis in plants and hormone effects

Abstract

We have identified nine genes encoding peroxiredoxins (Prxs) in the model legume Lotus japonicus. The genes belong to the typical four classes of Prxs found in plants: 1Cys (1C-Prx), 2Cys (C2-PrxA and C2-PrxB), PrxQ (PrxQ1, PrxQ2, and PrxQ3), and type II (PrxIIB/C, PrxIIE, and PrxIIF). All genes were found to be transcribed, except PrxQ3. The expression pattern among the various plant organs and tissues is gene specific, with some overlapping in genes of the same class. Additionally, we have assessed the response of Prx genes to treatments with classical hormones and related stress and signaling compounds in roots of hydroponically-grown plants. Most Prx genes, especially 1C-Prx, were responsive to indole-3-acetic acid (IAA) or cytokinins (CKs). There were limited and specific changes of Prx expression after plant treatment with abscisic acid (ABA), 1- aminocyclopropane-1-carboxylic acid (ACC), gibberellic acid (GA), or jasmonic acid (JA). The unique expression pattern for each Prx gene within the plant and the specific response of Prx expression to hormones support a non-redundant role for most of these genes.