Occurrence of hydroxycinnamoylputrescines in xylogenic bamboo suspension cells

抄録

To explore the chemical basis of xylogenesis in bamboo cells, we compared secondary metabolite compositions between xylogenic and non-xylogenic suspension cell cultures of bamboo (Phyllostachys nigra), which we developed previously. Two compounds, one major and one minor, showed large-scale increases in the cells cultured under two lignification (xylogenic) conditions, compared with cells cultured under proliferation (non-xylogenic) conditions. Based on spectroscopic analyses, the major compound was identified as feruloylputrescine (FP) and the minor compound was identified as p-coumaroylputrescine (pCP). We examined the accumulation profiles of these hydroxycinnamic acid amides during a 16-day culture period. When cells were kept in proliferation conditions for 16 days, the contents of FP and pCP peaked at 2 days (0.32 and 0.25 nmol mg⁻¹ fresh weight, respectively) and decreased to trace levels thereafter. In contrast, the FP content increased throughout the 16-day culture period, reaching maximum levels of 4.3 and 6.8 nmol mg⁻¹ fresh weight in the two xylogenic conditions. The pCP content was lower than that of FP under both xylogenic conditions. The pattern of FP accumulation resembled that of lignin accumulation, as monitored by phloroglucinol-HCl staining. It is likely that FP plays a role in xylogenesis in suspension-cultured bamboo cells.