Wednesday, February 2, 2011

Siderophore Production by Trichoderma

This post is in continuation to Competition and Rhizosphere Competence of Trichoderma: A Magical plant health manager.

Siderophores (Gr. “iron-bearers”) are defined as ‘low molecular weight, virtually ferric specific legends, the biosynthesis of which is carefully regulated by iron and the function of which is to supply iron to the cell’. Iron is generally present in the microbial environment as the ferric ion (Fe (III)), which is virtually insoluble in the presence of O2 and therefore, is not available for microbial growth. Siderophore chelate Fe (III) and microbial membrane receptor proteins specifically recognize and take-up the siderophore-Fe-complex. This results in making iron unavailable to rhizosphere microorganisms, including plant pathogens, which produce less or different siderophores with lower binding coefficients. The result is less pathogen infection and biological control. Siderophores also help in improving antagonistic activities, rhizosphere competence and plant growth.
Trichoderma virens is reported to produce three types of hydroxymate siderophores: a monohydroxamate (cis- and trans-fusarinines), a dipeptide of trans-fusarinine (dimerum acid), and a trimer disdepsipeptide (copragen).

In coming post I shall be discussing more about