Plant cells are supported and strengthened primarily by their cell walls, which are rigid structures made up mainly of cellulose, hemicellulose, and pectin. The cell wall provides structural integrity, protects the plant cells, and helps maintain their shape.
In addition to cellulose, some plant cells may also contain lignin, which adds further strength and rigidity, especially in woody plants. The combination of these components enables the plant to withstand various environmental stresses and contributes to overall plant stability.
Furthermore, the vacuole in plant cells also plays a role in maintaining turgor pressure, which further supports the cell structure by pushing the cell membrane against the cell wall.