Microfibril orientation in differentiating and maturing fibre and parenchyma cell walls in culms of bamboo (Phyllostachys viridi-glaucescens (Carr.) Riv. & Riv.)

Abstract

Results of trials using chemical and enzymatic wall extractarits for thc remord of matrix materials for in titu ohsenations of newl>- deposited microfibrils are described. Obscnations were then made of the orientation of microfibrils on the inner walls of differcntiatins and maturing fibres and parenrhyma cells under the FESEkf. Orientation changes \wre similar in both cell types. During veq early primary call de\relopment. dcpositiori of microfibrils was in more or less axial alignment, which was latcr superseded by microfibrils in transversr orientation (90' to the long axis). A transverse orientation of microfibrils rcmaiiicd throughout much of primar) wall synthesis, until an abrupt shift occurred to a sloped orientation during late primary wall synthesis. Microfibrils of the first sccondaq- \Val1 laycr werc in axial al&gnmcnt or stecply sloped. In subsequent secondary wall deposition there was an altcrnatiori betwcen a trans\wse and a sloped or axial alignmcnt in maturing fihrcs and parenchyma cells.