Arbuscular mycorrhizas formed by Asphodelus fistulosus and Glomus coronatum: Three-dimensional analysis of plant nuclear shift using laser scanning confocal microscopy

Two main morphological types of arbuscular mycorrhizas (AM) are recognised, the Arum-type and the Paris-type. Most research has focused on the Arum-ty pe, including studies of the influence of colonisation on the plant at the cellular level. Modifications in the size, position and shape of plant nucl ei in colonised and uncolonised cells of the Paris-type AM formed by Asphod elus fistulosus L. inoculated with Glomus coronatum Giovannetti were invest igated in this study. The plants were grown in nurse pots to achieve near s ynchronous colonisation. Laser scanning confocal microscopy (LSCM) was used to visualise root material and to quantify plant nuclear shift in three di mensions, which has not been achieved in the past. In each colonised cell c ontaining arbusculate coils there was a quantifiable increase in the distan ce from the centre of the nucleus to the closest cell wall and in the volum e of the plant nucleus. Similar effects occurred in cells with hyphal coils but were not quantifiable because of small numbers. The position and size of the nucleus did not change in uncolonised cells of either inoculated or uninoculated plants. The significance of the results is discussed with resp ect to the development of Paris-type AM.