Polymerization degree of chitosan affects structural and compositional changes in the cell walls, membrane lipids, and proteins in the leaves of Ipomoea purpurea: An FT-IR spectroscopy study

• Published in: International journal of biological macromolecules 2020-11, Vol.162, p.715-722
• Main Author: Acemi, Arda
• Format: Article
• Language: English
• Subjects: Biopolymer; Cell Wall - chemistry; Chitosan - chemistry; Convolvulaceae; Ipomoea - chemistry; Ipomoea - growth & development; Membrane Lipids - chemistry; Morning glory; Plant Leaves - chemistry; Plant Proteins - chemistry; Polymerization; Polymerization degree; Polysaccharides - chemistry; Protein Structure, Secondary; Vibrational spectroscopy
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2020.06.171

This research aimed to investigate the polymerization degree (DP) –dependent effects of chitosan treatments on structural and compositional changes in certain cell wall polysaccharides (mainly lignin), membrane lipids, and proteins of in vitro–propagated Ipomoea purpurea leaves through FT-IR spectroscopy. The chitosan oligomer mixture (DP 2–15; CHI-OM) and chitosan polymer (DP 70; CHI-P) applied at 5, 10, and 20 mg L−1 concentrations induced different patterns of biomolecular changes in I. purpurea leaves. The chitosan variants enhanced the destabilization of cell membrane structures. CHI-P treatments increased the lipid structure and protein content of the membranes more than CHI-OM treatments. CHI-OM treatment was found to have the ability to induce the formation of β-sheet structures with a low number of strands, whereas CHI-P treatment was found to have the ability to trigger the formation of more extended α-helix structures in the secondary structure of proteins. CHI-P treatments increased lignin synthesis more than CHI-OM treatments. However, CHI-OM at 10 mg L−1 concentration was more effective than CHI-P treatments in the induction of cell wall polysaccharide synthesis. These findings suggest that the polymerization degree of chitosan plays a role in changing structures and compositions of the biomolecules present in the leaves of I. purpurea.