Genome-Wide Analysis of the Chickpea Peroxiredoxin Gene Family Reveals Subfamily-Specific Expression Partitioning

Peroxiredoxins (Prxs) are thiol-dependent peroxidases that couple hydrogen peroxide (H2O2) detoxification with redox signalling, but the family has not been characterized in chickpea (Cicer arietinum L.). Here, we performed a genome-wide analysis of the CaPrx family integrating phylogeny, gene structure, conserved motifs, duplication history, promoter architecture, and public RNA-seq data. Eight CaPrx genes were identified and classified into the four canonical Prx subfamilies. The duplicated pair Ca2CPrxA/Ca2CPrxB showed significant purifying selection (Ka/Ks = 0.058; p < 10−20), whereas Ca1CPrxA and Ca1CPrxB differed at only three nucleotide positions, which is consistent with a very recent duplication. In a 32-tissue expression atlas, expression was partitioned by subfamily: Ca2CPrxA, Ca2CPrxB, and CaPrxQ were most abundant in photosynthetic tissues, the 1-Cys Prx transcript accumulated strongly during late seed maturation, and CaPrxIIA was highly and constitutively expressed. In the roots of a drought-sensitive and a drought-tolerant genotype, no CaPrx gene changed by more than two-fold under drought. These results provide a curated genomic and expression reference for the chickpea Prx family and point to subfamily-specific expression domains, particularly the seed-associated 1-Cys Prx, as priorities for functional studies.