Plant Cell Walls

Question 1

What are the different types of stains used to visualize cell wall components? What do they stain and what cells can be see ?

Answer 1

Sudan III- stains hydrophobic components. Such as Suberin and cutin. Will stain cork, casparian strip and epidermis cells.

Ruthernium Red- has positive charge and bings to acidic polysaccharides such as Pectins. Pectin is present in primary cell walls so any cell walls with a primary cell wall.

Calcoflour white- intercalate with polysaccharides that have 1,4 bonds. Therefore stains any cell with cellulose

Question 2

More stains

Answer 2

Phloroglucinol- HCl: reacts with phenolic aldehydes, will stain lignin, structures like xylem and fiber will appear.

Lectin-binding: recognises specific sugar and when dyed and applied to a specimen it binds to the polysaccharide with that specific sugar.

Antibody-binding: antibodies are specific for the cell wall type, it recognises specific epitopes and will highlight specific cell types.

Question 3

Characteristics of Cellulose and Xyloglucan

Answer 3

Cellulose-
beta- 1,4 linked glucose
Forms rigid microfibrils
Highly crystalline structure
Provides structural support

Xyloglucan
It helps cross link cellulose microfibrils
More flexible than cellulose
Contains other sugars in its side chains
Also has a beta 1,4 linked glucose backbone