Background
The class III peroxidase (PRX) gene family is a plant-specific member of the PRX superfamily that is closely related to various physiological processes, such as cell wall loosening, lignification, and abiotic and biotic stress responses. However, its classification, evolutionary history and gene expression patterns are unclear in wheat and
Aegilops tauschii
.
Results
Here, we identified 374, 159 and 169 PRXs in
Triticum aestivum
,
Triticum urartu
and
Ae. tauschii
, respectively
.
Together with PRXs detected from eight other plants, they were classified into 18 subfamilies. Among subfamilies V to XVIII, a conserved exon-intron structure within the “001” exon phases was detected in the PRX domain. Based on the analysis, we proposed a phylogenetic model to infer the evolutionary history of the exon-intron structures of PRX subfamilies. A comparative genomics analysis showed that subfamily VII could be the ancient subfamily that originated from green algae (
Chlamydomonas reinhardtii).
Further integrated analysis of chromosome locations and collinearity events of PRX genes suggested that both whole genome duplication (WGD) and tandem duplication (TD) events contributed to the expansion of
T. aestivum
PRXs (
Tae
PRXs) during wheat evolution. To validate functions of these genes in the regulation of various physiological processes, the expression patterns of PRXs in different tissues and under various stresses were studied using public microarray datasets. The results suggested that there were distinct expression patterns among different tissues and PRXs could be involved in biotic and abiotic responses in wheat. qRT-PCR was performed on samples exposed to drought, phytohormone treatments and
Fusarium graminearum
infection to validate the microarray predictions. The predicted subcellular localizations of some
Tae
PRXs were consistent with the confocal microscopy results. We predicted that some
Tae
PRXs had hormone-responsive
cis
-elements in their promoter regions and validated these predicted
cis
-acting elements by sequencing promoters.
Conclusion
In this study, identification, classification, evolution, and expression patterns of PRXs in wheat and relative plants were performed. Our results will provide information for further studies on the evolution and molecular mechanisms of wheat PRXs.
Electronic supplementary material
The online version of this article (10.1186/s12864-019-6006-5) contains supplementary material, which is available to authorized users.