Physiological responses associated with Fe‐deficiency stress in different plant species

Abstract

Experiments with a few crop plants have revealed the existence of different mechanisms of Fe‐stress tolerance. However, there are some physiological responses obtained in common, like pH reduction, release of reductant chemicals, and chlorosis recovery in the Fe‐efficient cultivars. Five cultivars of tobacco were subjected to Fe‐deficiency stress in nutrient culture. All of them exhibited varying degrees of chlorosis, released riboflavin into the medium at different stages of growth, and reduced the pH. Studies with ash gourd and pumpkin showed that the former was susceptible and the latter tolerant to Fe‐stress. The pH of the medium was reduced followed by release of riboflavin and formation of swelling and yellowing of root‐tip in pumpkin. The ash gourd cultivar CO‐2 responded to treatment with 100 ppm phthalic acid by producing new green leaves.

Key words:

• Chlorosis
• pH reduction
• Root‐tip swelling
• Riboflavin
• Phthalic acid
• Ash gourd
• Pumpkin