Emerging roles in plant biotechnology for the second messenger cGMP - guanosine 3’, 5’-cyclic monophosphate

Second messengers are small transient molecules that transmit and/or modulate environmental or hormonal signals linking them to complex and often systemic physiological responses. Recent reports have renewed interest in the second messenger guanosine 3’, 5’-cyclic monophosphate (cGMP) since it has been shown to directly mediate an ever increasing number of plant responses ranging from themodification of cyclic nucleotide gated ion channels to the regulation of tran scription of many cGMP responsive genes. Here some of these cGMP dependent responses will be reviewed emphasising their role in plant stress responses. Finally, potential applications of cGMP in plant biotechnology will be discussed.