Bacterial Flavoprotein Can Increase Plant Tolerance to Iron Starvation

Iron starvation in plants is a major concern in agriculture. It causes the decline of many photosynthetic activities and is manifested by chlorotic symptoms in young leaves and poor root formation. This ultimately leads to growth retardation, stasis, and death when disregarded.

To investigate whether plants can have an increased tolerance to iron deficiency, researchers engineered tobacco plants with bacterial flavodoxin (Fld). Fld is a flavin mononucleotide containing protein that is not found in plants. The compound was shown to counter the symptoms of iron deficit and can restore normal rates of growth and reproduction.

Results of the study indicate that transgenic tobacco plants expressing Fld in their chloroplasts grew normally on iron deficient media and did not show decline of photosynthetic components. Previous research has shown that plants with Fld have generalized tolerance to various sources of oxidative and environmental stresses. The researchers explained that the increased tolerance to iron starvation was because Fld permitted the redistribution of the limited amount of available iron to other demanding metabolic pathways, thereby helping the organism.

The paper published in the Proceedings of the National Academy of Sciences (USA) can be accessed at http://www.pnas.org/cgi/content/abstract/0704553104v1.