BIO 1130 Lecture Notes - Lecture 21: Vessel Element, Devonian, Lignin

• School: University of Ottawa
• Department: Biology
• Course: BIO 1130
• Professor: Jon Houseman

Document Summary

Large plants that we would see today as ferns and plants that do not have vascular tissue, from there, the beginning of vascular tissue. Lignified secondary wall, tracheary cells and sieve elements long-lived sporophyte. Lignin ends up inside the cellulose cell wall (as a secondary cell wall), and therefore there is no water leaking into the cell wall. The cohesive properties of water, working with a hydrophobic tube-like structures is the beginning of the vascular system in plants: indigestible. A lot of cross-linking, very difficult to break down. Therefore there is a large amount of plants because there is nothing to break it down: bacterial and fungal lignases. Figured out a way to break lignin down: toxic to bacteria. They come in pairs and they are alive and stay alive. There is always a companion cell beside each sieve cells. The companion cell is pouring sugar into the sieve element, and the element is also receiving water from the xylem.