Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/10/2008
Publication Date: 1/10/2009
Citation: Chen, X. Brenneman, T. Culbreath, A. Holbrook, Jr. C.C. Guo, B. 2009. Two peanut germin-like genes and the potential superoxidase dismutase and oxalate oxidase activities. Plant and Animal Genome XVII Conference, San Diego, CA. on January 10-14, 2009.
Interpretive Summary: not required
Technical Abstract: Germins and germin-like proteins (GLPs) genes are members oflarge multi gene families. These genes have been reported to play a role directly or indirectly in plant defense response. A number of GLPs have been demonstrated to have superoxidase dismutase (SOD) or oxalate oxidase (OxO) activity leading to production of hydrogen peroxide. Two peanut germin-like genes, AhGERL, originating from peanut leaf cDNA libraries, and AhGERS from seed libraries, were identified. The AhGERL including 991 bp cDNA sequences encodes a 219 amino acid protein with a 21-residue signal peptide. After cleavage of the signal peptide, it has a mass of 20.84 kDa. The AhGERS comprised of 744 bp cDNA encodes a protein with 220 amino acid residues containing a putative signal peptide of 24 residues, with a mass of 20.63 kDa after removal of the signal peptide. The two proteins both contain three motifs, Q/NDL/FCVAD, G(X)5HXH(X) 11G and G(X)5P(X)4H(X)3N, which are characteristic to germin-like proteins. Furthermore, the deduced protein of AhGERL consists of the "germin box" (HI/THPRATEI), which is a conserved sequence shared by germins within the motif G(X)5HXH(X)11G. Searches of GenBank database indicate that AhGERL and AhGERS, with approximately 37% of amino acid similarity to each other, exhibit respectively up to 76% and 82% amino acid identity to certain plant germin-like proteins. Southern blot analysis showed that the two genes possibly exist at least four copies in the peanut genome. Northern blots conducted with total RNA from seed and leaf tissues indicated that AhGERS is mainly expressed in peanut seed. Enzyme assay indicated that the coding sequence of AhGERL exhibited superoxide dismutase activity but no detectable oxalate oxidase activity, while either activity was not detected for AhGERS. The potential function related to disease resistance will be studied.