Genome-Wide Identification and Characterization of Light HarvestingChlorophyll a/b Binding Protein Genes in Barley (Hordeum vulgare L.)

Light harvesting chlorophyll a/b binding proteins (LHC) play an important role in photosynthesis and development of plant. However, limited data is available for this important gene family in barley, especially for their biological functions. In this study, sequences of rice and Arabidopsis LHCs were used as queries to identify the respective orthologues from available barley genomic database. Total 17 non-reduntant HvLHCs were identified. Genomic sequences of these genes were ranged from 780 bp to 2779 bp in length, and ORF sequence of 738 bp to 933 bp. The phylogenetic relationship of members from barley, rice and Arabidopsis revealed that most of them were common to the three species, while some of them were specific to Arabidopsis or the poaceae family. Cis-element analysis showed that along with the universal transcription initiation and enhancement relevant elements, there were also light as well as biotic and abiotic stresses responsive elements in promoter regions of these HvLHCs. Additionally, these genes exhibited quite similar expression pattern during the development of barley plant according to the public normalized RNA-seq and barley array datasets, but responded distinctively to different treatments including dark, heat, salinity and drought, which were confirmed by quantitative real-time PCR analysis. This is the first report of identification of HvLHCs at the genome level, and results presented here would be useful not only for determining the precise role of HvLHCs during barley development and abiotic stress responses, but also for using them in molecular breeding of barley varieties with high yield or high tolerance to stresses.