The following points highlight the five phenomenon that takes place because of the chemical changes in the cell wall. The phenomenon are: 1. Lignification 2. Cutinization 3. Suberinization 4. Mineralization 5. Mucilaginous Change. Phenomenon # 1. Lignification: In this phenomenon lignin is the substance of impregnation. Lignin is a phenolic polymer and contains three subunits namely-coumaryl, guiacyl and sinapyl-propane. It [...]
In this article we will discuss about the origin of cell wall in plants. Initially middle lamella creates a new boundary between the two-daughter nuclei of a dividing cell. The components of cell wall deposit on either side of middle lamella to form the cell wall. In a non-vacuolated cell, nucleus is usually present at the centre where it divides. [...]
In this article we will discuss about the layers of the spore and pollen wall. Sporoderm stratification (Erdtman's concept): Sporoderm (L. sporodermis), i.e. the spore and pollen wall is composed of distinct layers or subdivisions, the sequence of which is as follows from outside inwards in a fresh pollen grain and spore. Sclerine (Gr. Scleros means hard-Fig. 4.1 A & [...]