Successful fertilisation in the angiosperms depends on pollen tubes finding their way to the ovule. In vivo, pollen tubes frequently change their direction of growth until they finally reach the micropyle. Once in the female tissues, changes in growth direction must arise from the perception of ill-characterised spatial, mechanical electrical and chemical cues from the stigmatic environment. Exactly how these signals are perceived and transduced is not yet known.
It is interesting that when addressing the reluctance of cAMP signalling pathways in plants, Bolwell (1995) already put forward this same intimacy between AC and stress signalling […] Even more significant to this work is that the same rationale could be applied to pollen tubes: localised interaction with environmental cues at the very tip, where reorientation can occur within a few minutes.
Sete anos depois, ocorre-me: será que isto faz de mim uma perita em relacionamentos?