Phylogenomic Relationships of Rice Oxalate Oxidases to the Cupin Superfamily and Their Association with Disease Resistance QTL

Abstract

Rice oxalate oxidase genes (OXO) may play a role in resistance to Magnaporthe oryzae. Genome analyses showed four tandemly duplicated OXO genes, OsOXO1-OsOXO4, which mapped to a blast resistance QTL in chromosome 3. These genes have >90% nucleotide and amino acid identity, but they have unique gene structures, conserved motifs, and phylogeny compared to the 70 other members of the cupin superfamily in the Nipponbare genome, which were divided into several classes. In resistant and susceptible Vandana/Moroberekan advanced backcross lines, only OsOXO4 was expressed during rice-M. oryzae interactions, and its expression increased earlier in resistant than susceptible lines. The earlier expression of OsOXO4 in resistant lines correlated with a 26-bp promoter insertion containing an additional copy of the bacterial responsive nodulation cis-element. Our results showed that OsOXO1-4 are in a separate class of rice cupin genes and supports a role for the promoter variant of OsOXO4 in resistance to M. oryzae.

Germin-like proteins (GLPs) in cereal genomes: gene clustering and dynamic roles in plant defence

“…4), with the duplications likely to be recent and less likely to have evolved new functional attributes. Tandem duplication of genes from the closely related OXO cupin subclasses has also been reported (Carrillo et al 2009). …”

“…The clustering of proteins in a structure-based phylogeny study of bicupin-containing proteins revealed that N-and C-terminal cupin domains had evolved independently of each other (Agarwal et al 2009). Sequence-based phylogenetic analyses of all cupindomain-containing proteins in rice can clearly separate monucupins and bicopins, despite >90% amino acid and nucleotide identity Carrillo et al (2009).…”

“…Structural characteristics of these proteins offer a more robust system of classification due to the clustering of proteins with conserved functions (Agarwal et al 2009). The well-conserved homogeneous group of so-called 'true germins' are those found to have OXO activity and are almost exclusively found within cereal plant species (Lane et al 1991;Woo et al 2000;Bernier and Berna 2001;Carrillo et al 2009;Davidson et al 2009). The heterogeneous GLP group of proteins have a far wider taxonomic range in plants and include germin-motif Fig.…”

Application of an Improved Proteomics Method for Abundant Protein Cleanup: Molecular and Genomic Mechanisms Study in Plant Defense

“…S6A and B). Os03g48770 also shares 97% similarity with Os03g48780, which encodes an oxalate oxidase involved in ROS signaling (16). It will be interesting to further study if this gene is involved in rice defense against both insect and pathogen, and how the up-stream and downstream regulation is involved.…”

“…The cupinlike protein was previously reported to be important for reactive oxygen species (ROS) production during the defense response. For example, in a study researched by Carrillo et al, a cupin-like protein Os03g48470 was demonstrated to be an oxalate oxidase to produce H 2 O 2 (16). However, it was not clear which one of more than 100 cupin-like proteins in the protein family was actually involved in plant defense against herbivorous insects (17)(18)(19).…”