Tree maturation characterized by in vivo studies in Pinus radiata on pH patterns at the apex and systemic electrophysiological responses

Pinus radiata plants of different ages (juvenile and adult) were analysed to identify developmental stage specific physiological markers. Patterns of cytoplasmic pH measured in the apical meristem using the fluorescent probe carboxy SNARF-1 and confocal laser-scanning microscopy became more homogeneous during development with the average pH shifting during maturation to more acidic values in all tested genotypes. Electrophysiological responses to external signals were measured as surface compound potential changes using surface electrodes. The responsiveness to light and temperature signals decreased during development in all genotypes, with the exception of a non-flowering one.