bundle sheath

A bundle sheath is a layer of cells that surrounds a vascular bundle in plants. Vascular bundles contain xylem and phloem, which are the plant's transport tissues for water, minerals, and food.12

In certain plants, like corn and sugarcane, these bundle sheath cells play a crucial role in a specialized form of photosynthesis called C4 carbon fixation. This process helps these plants conserve water, especially in hot and dry conditions, by concentrating carbon dioxide within the bundle sheath cells. This mechanism minimizes a process called photorespiration, allowing for efficient sugar production and leading to high biomass yields.3