In the section of a monocot leaf shown in the given diagram, what would be true for the structures labeled X?

1. They regulate the opening and closing of the stomata in the adaxial surface of the leaves
2. Due to presence of lignin in their walls they provide support to the leaf surface in windy conditions
3. They are involved in folding and unfolding of leaf tissue to control light intensity and reduce overall water loss
4. They are abnormal cells produced during healing of the adaxial surface after injury and are common portals of entry of viruses into the plants