Differences between primary and secondary cell wall in plants

S.N. Primary cell wall Secondary cell wall
1. It is formed in a growing cell. It is formed in a mature cell.
2. It lies inner to the middle lamella. It lies inner to the primary cell wall outside the cell membrane.
3. It is present in all the plant cells. It is present in certain cells only. E.g. cells involved in mechanical support and water transportation.
4. It is elastic and capable of expansion in a growing cell. It is rigid and incapable of expansion.
5. It grows in thickness by intussusception (growth by the deposition of cellulose). It grows in thickness by accretion (growth or increase by the gradual accumulation of additional layers or matter).
6. It consists of a single layer of wall material. It consists of 3 or more layers of wall material.
7. It is 1-3µm thick. It is 5-10µm thick.
8. Its cellulose micro-fibrils are short, wavy and loosely arranged. Its cellulose micro-fibrils are long, straight and compactly arranged.
9. It lacks pits. It has pits at certain places.
10. It lacks additional materials. It has additional materials like lignin, suberin etc.
11. Its water content is about 60%. Its water content is about 30-40%.
12. It has relatively low cellulose content. It has relatively high cellulose content.
13. It has relatively high hemicellulose, protein and lipid contents. It has relatively low hemicellulose, protein and lipid contents.
                            Primary and secondary cell wall

Differences between primary and secondary cell wall in plants