According to most recent findings, growth regulating factors (GRFs) are
plant-specific transcription factors (TFs) that play important roles in many
processes, including abiotic and biotic stress response mechanisms.
Completion of the common bean (Phaseolus vulgaris) genome project has
provided researchers with the opportunity to identify all GRF genes in this
species. With this aim, a genome-wide in silico study was performed and 10
GRF proteins (called PhvGRFs) were identified in the common bean genome.
Conserved and mandatory motifs (QLQ and WRC) were confirmed in all identified
PhvGRFs and two segmental duplication events were determined. Most of the
PhvGRFs were found to be more similar to Arabidopsis thaliana GRFs than to
Zea mays GRFs in a phylogenetic tree. According to the expression analysis of
10 PhvGRFs, inversely related expression patterns were observed in the roots
of Yakutiye and Zulbiye cultivars based on their capacity to adopt to drought
stress. After drought treatment of the Zulbiye cultivar, a drought-sensitive
common bean cultivar, PhvGRF1, PhvGRF2, PhvGRF3, PhvGRF5, PhvGRF6, PhvGRF9
and PhvGRF10 genes were upregulated 2- to 4-fold in root tissues, as compared
to the untreated control. The trend of PhvGRF1, PhvGRF2, PhvGRF3, PhvGRF5,
PhvGRF6, PhvGRF7, PhvGRF9 and PhvGRF10 genes showed a consistent decline of
2- to 6-fold in root tissues of the drought-tolerant Yakutiye cultivar
subjected to 24 h of drought stress. We demonstrated that the expression
patterns of the identified PhvGRFs correlated with the drought-stress
response in a cultivar-specific manner in the common bean. We suggest that
members of the GRF family can also be used for genetic engineering
applications in the common bean.
Peer Review #1 of "Genome-wide in silico identification of membrane-bound transcription factors in plant species (v0.1)"
