The Class III Peroxidase (POD) Gene Family in Cassava: Identification, Phylogeny, Duplication, and Expression.

Yan Yan,Hai Yang,Chunlai Wu,Yu Wang,Xupo Ding,Zehong Ding,Wei Hu,Weiwei Tie

doi:10.3390/ijms20112730

Abstract

The class III peroxidase (POD) enzymes participate in plant development, hormone signaling, and stress responses. However, little is known about the POD family in cassava. Here, we identified 91 cassava POD genes (MePODs) and classified them into six subgroups using phylogenetic analysis. Conserved motif analysis demonstrated that all MePOD proteins have typical peroxidase domains, and gene structure analysis showed that MePOD genes have between one and nine exons. Duplication pattern analysis suggests that tandem duplication has played a role in MePOD gene expansion. Comprehensive transcriptomic analysis revealed that MePOD genes in cassava are involved in the drought response and postharvest physiological deterioration. Several MePODs underwent transcriptional changes after various stresses and related signaling treatments were applied. In sum, we characterized the POD family in cassava and uncovered the transcriptional control of POD genes in response to various stresses and postharvest physiological deterioration conditions. These results can be used to identify potential target genes for improving the stress tolerance of cassava crops.

Highlights

Peroxidases (EC 1.11.1.X) form a large family of enzymes that are widely distributed in living organisms and catalyze the oxidoreduction reaction between hydrogen peroxide (H2O2) as an electron acceptor and diverse electron donors, such as auxin, phenolic compounds, or secondary metabolites [1,2]
According to the 211 POD protein sequences from Arabidopsis and rice genome databases, 91 POD members were predicted from the cassava genome using BLAST and Hidden Markov Model-based search (HMMER) methods
To examine the expression profiles of MePOD genes after the plants were exposed to stress and related signaling treatments, the 60-day-old Arg7 variety was treated with 100 μM methyl jasmonate (MeJA) for 0, 2, 6, 10, and 24 h; 300 mM NaCl for 0 h, 2 h, 6 h, 3 days, and 14 days; a low temperature (4 ◦C) for 0, 2, 5, 15, and 48 h; 100 μM salicylic acid (SA) for 0, 2, 6, 10, and 24 h; 200 mM mannitol for 0 h, 2 h, 6 h, 3 days, and 14 days; 100 μM abscisic acid (ABA) for 0, 2, 6, 10, and 24 h; 10% H2O2 for 0, 2, 6, 10, and 24 h; or Xanthomonas axonopodis pv manihotis (Xam) for 0, 2, 6, 12, and 24 h

Summary

Introduction

Peroxidases (EC 1.11.1.X) form a large family of enzymes that are widely distributed in living organisms and catalyze the oxidoreduction reaction between hydrogen peroxide (H2O2) as an electron acceptor and diverse electron donors, such as auxin, phenolic compounds, or secondary metabolites [1,2]. According to their protein sequences and structure, peroxidases are classified as either non-heme peroxidases or heme peroxidases [3]. Prx proteins are involved in a variety of physiological processes, such as the cross-linking of cell wall components, salt tolerance, defense against pathogen attack, the oxidation of toxic reductants, and the metabolism of phytohormones [2,3,13,14,15,16,17]

Methods

Results

Conclusion