NON-DESTRUCTIVE EVALUATION OF PLANT CELL WALL ARCHITECTURE AND MECHANICAL PROPERTIES AT MICRO AND NANO LEVEL
Open Access
- Author:
- Xi, Xiaoning
- Graduate Program:
- Engineering Science and Mechanics
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- October 07, 2016
- Committee Members:
- Bernhard R.Tittmann, Dissertation Advisor/Co-Advisor
Bernhard R.Tittmann, Committee Chair/Co-Chair
Sulin Zhang, Committee Member
Samia A. Suliman, Committee Member
Seong H. Kim, Outside Member - Keywords:
- Mechanical properties
Elastic modulus
Atomic force microscopy
Nanoindentation
Scanning acoustic microscopy
Plant cell wall - Abstract:
- Fully hydrated primary plant cell walls in their natural state were characterized by Atomic Force Microscopy (AFM) imaging and Scanning Acoustic Microscopy (SAM) imaging. Nano level Cellulose microfibril organization and re-distribution during cell wall in different developing stages in onion bubbles were observed and provide insight understanding for wall growth. Results show that primary walls change their cellulose microfibrils architecture dynamically during growth. AFM based nanoindentation were developed and applied successfully to study the modulus properties of single layer hydrated walls in their natural state. Liquid media were changed and their effect on wall properties were captured by this nanoindentation technique. SAM micro level V(z) curve studies were carried out on fully hydrated cell walls and modulus properties were obtained. Effect of enzyme on cell wall property were reflected on the experimental results. The modulus results show that the pectins have great impact on out-of-plane modulus property with small deformation displacement while they have little effect on in-plane micro level modulus property. These non-destructive evaluation techniques open the door for accurate and efficient quantitative study of wall properties during cell wall growth and development.