Rhizosheaths in desert plants: Natural mechanisms and bioinspired technologies for water harvesting and dryland restoration

Rhizosheaths, which are sand sheaths formed around plant roots, represent a critical adaptation in many desert species, enabling survival under arid conditions through enhanced water and nutrient retention. Although rhizosheaths also occur in crops such as wheat and maize, this review emphasizes desert-adapted grasses and sedges that exhibit highly specialized rhizosheath structures and functions. We synthesize current knowledge on rhizosheath formation, microbial and biochemical interactions, and mechanisms of soil and atmospheric water harvesting. Our analysis shows that rhizosheaths significantly enhance local moisture availability, support beneficial microbial communities, and contribute to nutrient cycling in sandy soils. We also highlight the key role of mucilage chemistry and root-microbe interactions in stabilizing rhizosheaths under drought. The review highlights their ecological functions as nutrient-rich microhabitats and their role in supporting drought-adapted microbial consortia. We further explore how rhizosheath biology inspires bioinspired technologies such as hydrogels, root-zone irrigation systems, and exopolysaccharide-based seed coatings. In conclusion, we identify key knowledge gaps—particularly in mucilage composition, microbiome specificity, and the scalability of synthetic rhizosheaths—and propose future directions for climate-resilient agriculture and dryland restoration.