Independence of Imbibitional Chilling Injury and Energy Metabolism in Corn1
- Marc Alan Cohn and
- R. L. Obendorf2
Energy metabolism of 5 (low) and 13% (high) moisture Zea mays L. inbred ‘Oh51A’ kernels was measured at 0, 12, 24, and 48 hours at 25 C subsequent to imbibition at 5 C. Radicle growth was measured at 1, 2, 3, and 4 days. The interaction of low kernel moisture with imbibition at 5 C resulted in reduced radicle growth in seedlings. Oxygen uptake of whole kernels after imbibitional chilling was independent of initial kernel moisture. Differences in initial moisture also did not alter ATP levels of embryos and embryonic axes after chilling. ATP increased about 20-fold and adenylate energy charge of embryos increased from 0.2 to 0.8 during hydration at 5 C irrespective of initial moisture content. Mitochondria isolated from embryos of low moistttre kernels exhibited slightly higher respiratory rates 24 hours after cold imbibition but not at other sampling times. ADP/O .ratios and respiratory control ratios (succinate substrate) of isolated mitochondria were not altered by initial kernel moisture. A disruption of energy metabolism is not a primary cause of kernel moisture-mediated imbibitional chilling injury.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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