Aggregation-resistant proteins are adjusted during drought in sugarcane plants

During drought stress, plant cells reorganize their proteomes to counteract the adverse impacts of stress. Given that the intracellular environment differs between drought-stressed cells and cells under optimal growth conditions, it has been proposed that the physicochemical characteristics of proteins could also differ under stress. To test this hypothesis, we determined whether the number of proteins resistant to aggregation increases under drought stress conditions in sugarcane, a relevant agricultural species. To do this, we used nanoLC-MS/MS proteomic analysis to identify and count the number of aggregation-resistant proteins produced by sugarcane in response to drought stress. We found that the number of these types of proteins was almost three times higher under drought stress than under control conditions, most of which were predicted to be intrinsically disordered proteins. Under drought stress, we also detected many proteins that are recognized as drought stress-responsive proteins, including enzymes involved in the oxidative response. Interestingly, we found that although most of these enzymes are globular proteins, several of them are predicted to be intrinsically disordered proteins. These results back the idea that, in sugarcane, drought stress can trigger the induction of aggregation-resistant proteins. We propose that the accumulation of aggregation-resistant proteins could be part of the drought stress response, making our approach a potentially useful strategy for discovering novel drought-responsive proteins in other plant models.