3.4. Al effect on the root tip ultrastructure
The characteristics of soybean root tip cell ultrastructure
showed that Al toxicity harmed Z.3 more severely than Z.2. Without
Al stress, the configuration of the root tip cells was well structured
and the ultrastructural characteristics were normal: the nuclei
were found in random locations within the cell space, the nuclei
and karyotheca structures were clearly seen, the mitochondria’s
rounded kidney-shaped was well defined, the mitochondria were The root tip cells of Z.2 and Z.3 grown in the 10 mg L1 Al
solutions had a mixture of normal and abnormal characteristics
(Fig. 6): the cell wall had irregular thickness, the mitochondria and
vacuole inclusions were more than those observed in the check,
and the external membrane of the nuclei were swollen and its
borders had less clarity than those of the check. The mitochondria,
however, showed normal configurations and an abundant and
well-organized inner membrane system. Except for a large proliferation
of endoplasmic reticulum in Z.2, there was no other
observable difference between the two cultivars