What is an example of a plant adaptation that occurs due to mineral deficiencies?

Leaf scorch is a clear example of a plant adaptation that occurs due to mineral deficiencies, particularly a lack of essential nutrients such as potassium, magnesium, or calcium. When plants do not receive sufficient minerals from the soil, they may not be able to effectively carry out physiological processes, leading to drying and browning at the leaf margins—a condition known as leaf scorch. This adaptation is the plant's response to stress, where it might conserve water or reduce leaf area to minimize vapor loss.

The other choices highlight different plant conditions that may arise but do not directly exemplify adaptations resulting from mineral deficiencies. For instance, root rot typically results from overwatering or poor drainage rather than a nutrient shortage. New growth can occur in healthy plants or those recovering from deficiencies but isn't specifically an adaptation to nutrient lack. Bark peeling might indicate stress due to environmental factors but is also not a direct adaptation related to mineral deficiencies. Thus, leaf scorch stands out as the most relevant adaptation linked to the lack of essential minerals in plant nutrition.