Abstract
A comparative study of mitochondrial function in wheat seedlings was undertaken with the object to elucidate some biochemical bases of heterosis. Heterosis has been demonstrated in polarographic studies of mitochondria from a wheat hybrid 31MS x 28 and its parents. Mitochondria of the hybrid exceeded mitochondria of 31MS and 28 in oxidative phosphorylation, when they utilized alpha-ketoglutarate, malate, pyruvate plus malate, glutamate plus malate, succinate, and NADH as substrates. ADP:0 ratios greater than the "theoretical" maximum with four citric cycle intermediates--alpha-ketoglutarate, malate, pyruvate, and succinate were consistently observed in mitochondria of the hybrid. The high ADP:0 ratios of mitochondria of the hybrid indicated that these organelles are extremely energetic. Mixtures of parental mitochondria exceeded averages of the parents, i.e., they exhibited complementation and reflected activities of hybrid mitochondria except when succinate and NADH were used as substrate. Heterosis was observed with both NAD and FAD- linked substrates, whereas complementation was observed only with NAD-mediated substrates. The results were discussed from the point of view that the NAD and FAD- linked enzymes of the mitochondria may operate as regulatory systems to control energy flow through the electron transport pathway by the degree of "molecular" coupling..
Srivastava, Hari Krishna (1971). Studies of biochemical bases of mitochondrial heterosis in wheat (Triticum aestivum, Linn.). Doctoral dissertation, Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -181208.