Functional Exploration of Chaperonin (HSP60/10) Family Genes and their Abiotic Stress-induced Expression Patterns in .

Background: , the C4 dry-land cereal, important for food, fodder, feed and fuel, is a model crop for abiotic stress tolerance with smaller genome size, genetic diversity, and bio-energy traits. The heat shock proteins/chaperonin 60s (HSP60/Cpn60s) assist the plastid proteins, and participate in the folding and aggregation of proteins. However, the functions of HSP60s in abiotic stress tolerance in remain unclear.

Methods: Genome-wide screening and characterization of SbHSP60s were carried out along with tissue and stress-specific expression analysis.

Results: A total of 36 genes were identified in . They were subdivided into 2 groups, the and co-chaperonins encoded by 30 and 6 genes, respectively. The genes are distributed on all the chromosomes, chromosome 1 being the hot spot with 9 genes. All the HSP60s were found hydrophilic and highly unstable. The genes showed a large number of introns, the majority of them with more than 10. Among the 12 paralogs, only 1 was tandem and the remaining 11 segmental, indicating their role in the expansion of . Majority of the genes expressed uniformly in leaf while a moderate expression was observed in the root tissues, with the highest expression displayed by . From expression analysis, for drought, for salt, and for heat and and have been found implicated for cold stress tolerance and appeared as the key regulatory genes.

Conclusion: This work paves the way for the utilization of chaperonin family genes for achieving abiotic stress tolerance in plants.