Endodermal silicon deposits and their linear distribution in developing roots of Sorghum bicolor (L.) Moench.

Sangster, A.G. and Parry, D.W. (1976) Endodermal silicon deposits and their linear distribution in developing roots of Sorghum bicolor (L.) Moench. Annals of Botany, 40 (166). pp. 361-371.

[img] PDF
Restricted to ICRISAT researchers only


Sorghum seedlings were grown in nutrient solution containing 100 ppm SiO2 and over periods up to 14 days the progressive accumulation of Si deposits was recorded by means of an electron-probe microanalyser and a scanning electron microscope along the seminal root length. An acropetal linear gradient of Si deposits developed in the endodermis beginning at the proximal end of the root after 1 day, and subsequently extended distally until after 7 days the total silicified endodermal zone occupied the proximal 75% of the root length, a value which then remained relatively constant despite root extension. No Si was detected below this zone towards the apex. This result was believed to be related directly to the asynchronous gradient of cell maturation exhibited by the endodermis behind the apex, and specifically to the degree of wall development there. Opaline silica was deposited only in the endodermis, initially on the inner tangential wall surface after only 1 day, as spherical masses of coalesced primary particles for which the term 'silica aggregate' was proposed. A thin layer of silica over the wall surface was formed as a secondary phase. The aggregates reached mature size after approximately 7 days. Conditions favourable to the inception of silica deposition are discussed including the significance of the chemical composition of the aggregates and the importance of the degree of cellulosic thickening as well as the surface characteristics of the inner tangential wall

Item Type: Article
Author Affiliation: School of Plant Biology, University College of North Wales, Bangor, Gwynedd, UK
Subjects: Plant Production > Croping Systems
Divisions: Sorghum
Depositing User: Ms K Syamalamba
Date Deposited: 29 Aug 2012 07:40
Last Modified: 02 May 2017 08:04
URI: http://eprints.icrisat.ac.in/id/eprint/7577

Actions (login required)

View Item View Item