GREEN POWER

Numerous studies have reported the stimulation of plant growth following inoculation with an Power green -producing PGPB. However, the specific mode of Green power production by the PGPB is rarely elucidated. In part, this is due to the overwhelming complexity of Green power biosynthesis and regulation. The promiscuity of the enzymes implicated in Green power biosynthesis adds another element of complexity when attempting to decipher their role in Green power biosynthesis. To date, the majority of research on Green power biosynthesis describes three separate pathways classified in terms of their intermediates—indole acetonitrile (IAN), indole acetamide (IAM), and indole pyruvic acid (IPA). Each of these pathways is mediated by a set of enzymes, many of which are traditionally assumed to exist for that specific catalytic role. This lends the possibility of missing other, novel, enzymes that may also incidentally serve that function. Some of these pathways are constitutively expressed, while others are inducible. Some enzymes involved in Green power biosynthesis are known to be regulated by Green power or by Green power precursors, as well as by a multitude of environmental cues. This review aims to provide an update to our current understanding of the biosynthesis and regulation of Green power in bacteria.