Potential stress tolerance roles of barley germins and GLPs

Germins and germin-like proteins (GLPs) known as germination markers are encoded by multigene families in several plant species, including barley. To date, functional analysis has revealed germins and GLPs are involved in diverse processes such as embryonic development and stress responses. The aim of this study was the analysis of barley germins and GLPs. In this study, 80 putative germins and GLPs have been identified in barley by using known 17 germins and GLP sequences. Analysis of germins and GLPs showed all germins and GLPs are distributed on all seven chromosomes that most of them spread through chromosome 3, 4 and 7 with 16, 18 and 12 proteins on each, respectively. The protein sizes varied between 185 and 335 amino acids, with an average length of 225 aa. Twelve conserved motifs were found. While germin motifs 1 and 3 were detected in all germins and GLPs, some motifs were found to be related to signalization. Interestingly, protein-protein interaction analysis demonstrated some GLPs are associated with RAB6-interacting golgin, oligopeptide transmembrane transporter activity, beta-glucuronidase activity, protein N-linked glycosylation, multi-pass membrane protein, and proteins containing zinc finger (Znf) domain and RING (really interesting new gene)-type zinc finger domains. Our findings suggest that barley germins and GLPs may have diverse functions that make them important candidates for crop improvement.