The Effect Of HMC-Toxin To The Structure And Function Of Mitochondria In Maize With CMS And Normal Cytoplasm

The mitochondria from the normal cytoplasm (N) and CMS-C of Maize treated with C-toxin were observed by a transmission electron microscope (TEM) . The result showed that the outer membrane of C cytoplasmic mitochondria, after treated with C-toxin, appeared intact, the inner mitochondria! membranes were destroyed, and the cristae showed fragmentation to form small vesicles. But the outer membranes of N cytoplasmic mitochondria also appeared intact, and inner membranes were destroyed slightly. The outer and inner membranes of mitochondria not treated with C-toxin all appeared intact, and the cristae showed complete.The respiratory control ratios (RCR) were determined in the presence and absence of C-toxin with a Clark Oxygen electrode. The result showed that RCR declined equal to or more than 0.22 in the presence of C-toxin in C cytoplasm and respiratory ratio declined equal to or more than 20%; but in N cytoplasm RCR declined equal to or less than 0.06 in the presence of C-toxin and respiratory ratio declined equal to or less than 5%.From the above results, it is very clear that C-toxin is specificity to the structure and function of N and C cytoplasmic mitochondria. The site with C cytoplasm exists possible in the membrane of C cytoplasmic mitochondria. But the inference needs to study further in molecular level.