Lignificados

Lignificados is a term used in botany to describe plant tissues that have undergone lignification, a process where lignin, a complex polymer, is deposited within the cell walls. This process strengthens and hardens the cell walls, providing structural support and rigidity to the plant. Lignified tissues are crucial for the overall architecture and stability of plants, particularly in woody species.

The primary function of lignification is to impart mechanical strength. This allows plants to grow taller and withstand environmental stresses such as wind and gravity. Lignin also plays a role in water transport; it makes the xylem vessels rigid, preventing them from collapsing under negative pressure as water is pulled up from the roots to the leaves. Furthermore, lignin acts as a defense mechanism, making plant tissues more resistant to pathogen attack and herbivory due to its recalcitrant nature.

Lignification typically occurs in secondary growth, leading to the formation of wood and bark. Mature xylem and sclerenchyma cells are heavily lignified. The process involves the oxidative polymerization of phenylpropanoid units, primarily coniferyl alcohol, sinapyl alcohol, and p-coumaryl alcohol, which are cross-linked to form the lignin polymer. The specific composition of lignin can vary between plant species and even within different tissues of the same plant, influencing its properties. Understanding lignification is important in forestry, biofuel production, and the study of plant anatomy and physiology.