Identification of ultrastructural and biochemical cuticular markers influencing temperature of ice nucleation in selected genotypes of corn.

Corn is an economically important yet frost-sensitive crop, injured at the moment of ice nucleation. However, the influence of autumn temperatures on subsequent ice nucleation temperature is unknown. A 10-day chilling treatment under phytotron conditions ("mild", 18/6°C) or ("extreme", 10/5°C) generated no-visible damage but induced changes in the cuticle of the four genotypes in this study.

Allium fistulosum as a novel system to investigate mechanisms of freezing resistance.

Allium fistulosum was investigated as a novel model system to examine the mechanism of freezing resistance in cold hardy plants. The 250 × 50 × 90 µm average cell size and single epidermal cell layer system allowed direct observation of endoplasmic reticulum (ER), functional group localization during acclimation, freezing and thawing on an individual cell basis in live intact tissues. Cells increased freezing resistance from an LT50 of -11°C (non-acclimated) to -25°C under 2 weeks of cold acclimation.