Abstract
The relationship between photopigments and the terpene‐derived secondary metabolite, 2‐methylisoborneol (MIB), was analyzed in photoacclimated cultures of Pseudanabaena articulata Skuja throughout growth, during the diel cycle, and following chemical‐induced inhibition of the isoprenoid pathway. Accumulation of MIB coincided with the accumulation of lipophilic and phycobilin pigments during the early to mid‐exponential portion of the growth cycle with the greatest accumulation of MIB during the late‐exponential phase. Cellular release of MIB occurred as culture populations entered mid‐ to late‐logarithmic phase of growth and was greatest in irradiance‐stressed cultures. The greater correspondence of MIB accumulation with photopigments was seen in cultures transferred from a 12:12 h LD photoperiod alone and the consistent relationship between MIB and photopigment accumulation under varying irradiance suggested a photopigment‐dependent regulation for MIB synthesis. However, the consistent allocation of carbon into MIB during instances of phytofluene and tetrapyrrole biosynthetic inhibition within P. articulata and Oscillatoria perornata Skuja indicated that MIB accumulation is not limited by isopreniod‐carbon availability and does not appear to serve as an “overflow” product. Rather, MIB accumulation simply appears to reflect overall carbon accumulation resulting from increased cell metabolism.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have