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.

Automated summary

This study provides comprehensive information on in-silico identification and expression analysis of the SlHsp70 family genes in tomato under different trace metal elements. The results showed that these genes are widely expressed in various tissues of tomato and are involved in metal ions translocation and oxidoreductase activity. Cd2+ is a widespread heavy metal soil contaminant that severely affects tomato growth, and the increased expression of SlHsp70-11 may be used for breeding low Cd2+ enriched tomato varieties.