HSP101 is vital in resolving protein aggregates formed under heat stress. However, the role of this protein has not been adequately analyzed in larger populations considering their variation in growth and survival under non-heat stress, heat stress, and post-heat stress recovery conditions. Employing 29 Arabidopsis thaliana accessions representing diverse locations of the globe, we analyzed the natural variations in the amino acid sequence of HSP101, expression levels of HSP101 protein, and the thermotolerance response. Taking the HSP101 amino acid sequence of Col-0 ecotype as a reference point, the HSP101 sequence of the analyzed accessions showed significant variations in terms of deletions and substitutions of amino acids. The HSP101 protein level was variable under non-heat stress, heat stress, and post-heat stress recovery conditions amongst the accessions. The seedling basal thermotolerance response was likewise variable among the accessions, and importantly, HSP101 levels showed a positive correlation with the survival of the seedlings during the post-heat stress recovery conditions. The HSP101 levels and the growth of the seedlings showed a negative correlation, indicating that there is a trade-off between the HSP101 levels and the growth of the seedlings.
Tripathi et al. (Sun,) studied this question.