Genome-Wide Analysis and Expression Profiling of SlHsp70 Gene Family in Solanum lycopersicum Revealed Higher Expression of SlHsp70-11 in Roots under Cd2+ Stress

Background: Tomato is an important part of daily food, rich source of multitude nutrients, suitable candidate for bio-pharmaceutical production due to berry size and has numerous health benefits. Transcriptional regulation of metalloregulatory heat shock protein-70 family plays pivotal role in plants tolerance against abiotic stress factors including salinity, heat, cold, drought and trace metal elements such as cadmium (Cd2+). Methods: Here, we provide comprehensive report on in-silico identification of SlHsp70 family genes in tomato (Solanum lycopersicum) and their expression in tomato via qPCR analysis under broad range of trace metal elements. Results: In-silico analysis revealed 23 SlHsp70 family genes in tomato, phylogenetically divided into four groups I-IV and displayed expression in all tissues. Gene Ontology (GO) analysis revealed that SlHSP70 proteins were membrane localized which were involved in metal ions translocation and oxidoreductase activity to counter hyper-accumlation of reactive oxygen species (ROS). Conclusions: Cd2+ is a widespread heavy metal soil contaminent which is continously polluting fertile soils, a knotty issue which has serious implications over photosynthesis, nitrogen assimilation, minerals and water absorption by plants. Plants exposure to Cd2+ and subsequent qRT-PCR analysis revealed increased expression of SlHsp70-11 in tomato roots, which can be employed in breeding low Cd2+ enriched tomato varieties.