Identification of stress repressive zinc finger gene family and its expression analysis in rice under abiotic constraints

Background: Stress repressive zinc finger (SRZ) gene family in rice is one of the plant defense gene families that play a pivotal role in plant growth regulation and development, particularly under stressful conditions. However, there is no genome-wide survey regarding SRZ gene family in rice (OsSRZ) till date. Results: We studied, herein, this gene family by performing a genome-wide screening and we identified 25 OsSRZ gene members using Japonica cultivar as an investigating material. Their chromosome localizations, phylogenetic relationships, genomic structures, conserved domains and promoter cis-regulatory elements were analyzed. Besides, their spatio-temporal expression profiles and expression patterns under various hormones and stress treatments were also assessed. Based on the phylogeny and domain constitution, the OsSRZ gene family was classified into five groups (I-V). Conserved domains analysis demonstrates that OsSRZ proteins contain at least one highly conserved SRZ domain. The analysis of expression patterns of the SRZ gene family reveal that OsSRZ genes display tissue-specific expression patterns at various rice developmental stages and exhibit differential responses to both phytohormones and abiotic stresses. Furthermore, q-RT-PCR analysis reveals that Os SRZ genes exhibit different expression patterns under various abiotic stresses. We notice the presence of a single specific gene considerably or strongly up-regulated for each kind of abiotic stress. Over 12 OsSRZ genes analyzed with q-RT-PCR, solely 4 genes (OsSRZ 1, 2, 10 and 11) were found to be substantially or strongly up-regulated following abiotic stress. Notably, OsSRZ 10 and 11 were up-regulated under heat stress by 7 and 5 times, respectively. However, OsSRZ2 was up-regulated by 7 and 3.5 folds under salt and cold stresses, respectively. Interestingly, OsSRZ1 was up-regulated by about 3~11 times in 24 h following artificial oxidative stress application using 1 mM H2O2 . Conclusions: We deduce that some members of OsSRZ gene family function as abiotic stress marker in rice. At the genomic level and expression pattern, our genome-wide survey could provide promising and valuable insights to widen and strengthen further future investigation by leading a cutting edge research regarding the biological and molecular functions of this gene family.