The growth and behaviour in vitro of isolated plant cells

Abstract

Individual plant cells from tissue cultures of carrot, sunflower crown and Parthenocissus were cultured in nutrient solutions containing sucrose and mineral salts supplemented with IAA and coconut milk. The vacuolated cells which could be isolated in this way were studied by phase-contrast microscopy. Both cyclosis and massive movements of the nucleus and cytoplasm were observed. Though these isolated cells frequently grew in size they were not observed to divide. The capacity for cell division was found to reside only in the cambial cells which, in the original tissue culture, formed spherical layers generating tracheids towards the interior and large cortical cells towards the exterior. Small numbers of such cambial cells would proliferate in the medium used. The smallest group of such cells which gave rise to a cell colony contained ten to fifteen cells. The cell colonies produced maintained the spherical cambial structure of the tissues from which they were derived. They continued to grow for as long as four months and gave rise to numerous secondary colonies all of which followed the same pattern of growth. It was not found possible to develop true cell cultures by any of the techniques employed. Even when very few cambial cells were transferred the structure obtained was always an organized tissue with formed elements generated by a spherical cambium. The differentiated cells were not observed to divide but showed active cyclosis for as long as 4 months.