Effects of tensile force and nutrient availability on carbon uptake and cell wall synthesis in blades of juvenile Egregia menziesii (Turn.) Aresch. (Phaeophyta)

Abstract

Although field studies have demonstrated that algal morphology and biomechanics are correlated with water motion, the physical cue(s) eliciting those whole plant responses are unknown, as are the physiological changes that underlie the responses. Because changes in morphology and biomechanics involve changes in C metabolism, juvenile feather boa kelp Egregia menziesii Turn. (Aresch.) were incubated in the presence of H 14CO 3 − to identify experimentally synthesized materials. Four combinations of nutrient availability and tensile force (both varying with water motion) were employed to investigate the incorporation of 14C into whole tissue and cell wall compounds. Force significantly increased 14C incorporation into whole tissue, while nutrient availability and tissue age had no significant effect. The synthesis of cell wall materials was significantly increased by force application, was greater at low nutrient levels, and greater in younger tissue adjacent to the meristem. Tissue age and nutrient availability had significant interactive effects on cell wall synthesis.