Organ-specific proteomes of Selaginella convoluta provide insights into its desiccation tolerance mechanisms

Abstract

Selaginella convoluta is a desiccation-tolerant lycophyte capable of enduring water deprivation by arresting its metabolism when dry and reactivating it upon rehydration. Mechanisms to mitigate the harmful effects of desiccation have been investigated in an evolutionary context; however, plants have additional species-specific strategies refined by environmental conditions. Previous metabolome analysis pointed out S. convoluta as a source of chemodiversity. Shotgun proteomic analysis, conducted using an Orbitrap Elite and analyzed with PatternLab for proteomics, compared shoots and roots under two hydration conditions. Our approach identified 1,176 proteins. Proteins associated with photosynthesis, stress, and defense (primarily Reactive Oxygen Species scavengers and chaperones) were enriched in the shoots’ proteome in both hydrated and desiccated states. Post-hydration, roots exhibited exclusive proteins involved in defense, metabolism, and protein trafficking (notably 14-3-3-like proteins, and a putative Bet_v_1 domain-containing protein, which was 15.6 times more abundant in dehydrated roots). These results demonstrate that S. convoluta, when harvested in its dried state from its natural habitat, serves as a valuable source of molecular data, reflecting a realistic multifactorial environmental scenario.