Germins: A diverse protein family important for crop improvement

The germin protein family is comprised of two main subgroups in plants, oxalate oxidases (OXOs) and germin-like proteins (GLPs). These proteins are implicated in a variety of plant processes including germination, development, pollen formation, and response to abiotic and biotic stress. Here, we examine the phylogenetic relationships and functional diversity of the germin gene family across diverse genera, and then focus on rice (Oryza sativa) as amodel. In general, germin genes are expressed in all tissue types and are induced by biotic and/or abiotic stresses. In rice, many of the stress-induced germin genes physically co-localize with quantitative trait loci (QTL) for disease resistance, and emerging evidence suggests that small RNAs may regulate their transcript abundance. We analyze the extensive sequence, gene expression and functional data for germin family proteins and relate them to QTL map locations to predict additional candidate germin genes for future crop improvement. 2009 Elsevier Ireland Ltd. All rights reserved.