WHEAT, BRIAN P.* and JAMES L. SEAGO. Department of Biology, SUNY at Oswego, Oswego, NY, 13126. - Selected aspects of root development in a cotton variety and its genetically modified forms.
We examined root development in a variety of cotton and three of its
genetically modified derivatives, RR, Bt, and RRBt. The cortex in all
was essentially the same; Casparian bands developed in the endodermis
at 5-10 mm behind the root tip. There was then rapid development of
suberin lamellae opposite the protophloem; passage cells remained
opposite protoxylem. Further develpoment resulted in an endodermis
with Casparian bands, suberin lamellae, and some secondary wall
thickening. The cortex in the genetically modified forms was slightly
smaller than the control; none had an exodermis. The stele in the
control had fewer cells with lignified walls than the GMO's; secondary
growth quickly followed.
Key words: cell wall modifications, cotton, GMO's, root development