褪黑素调控缺氮胁迫下单针藻中油脂积累的影响

Effects of melatonin on regulating lipid accumulation in Monoraphidium sp. QLY-1 under nitrogen deficiency stress

研究缺氮条件下外源添加褪黑素(melatonin,MT)对单针藻Monoraphidium sp. QLY-1中油脂积累及相关基因表达水平的影响。结果表明,缺氮胁迫联合MT诱导,微藻的生物量比对照组(0. 89 g/L)提高了1. 12倍;油脂含量提高了1. 22倍,且最高可达51. 8%。此外,外源MT上调了rbcL和accD的表达水平及内源信号分子赤霉素(gibberellic acid,GA)的含量,同时下调pepc表达水平并抑制脱落酸(abscisic acid,ABA)的合成。研究表明,在缺氮胁迫条件下,微藻中油脂的大量积累可能与MT调控细胞内信号分子及相关酶基因的表达有关。

The effects of exogenous melatonin(MT)on lipid accumulation and lipid-related gene expression in Monoraphidium sp.QLY-1 under nitrogen deficiency conditions were investigated.The results showed that MT treatment together with nitrogen deficiency enhanced the biomass concentration of microalgae by 1.12-fold than that of control(0.89 g/L).Moreover,the lipid content increased by 1.22-fold with the lipid maximum of 51.8%.Furthermore,the exogenous MT up-regulated the expression levels of rbc L and acc D,and increased the accumulation of gibberellin acid(GA),which is an endogenous signal molecule.Simultaneously,the pepC expression level was down-regulated and the synthesis of abscisic acid(ABA)was restrained.These findings showed that massive accumulation of lipid in microalgae might be correlated with the regulation of intracellular signaling molecules and lipid-related enzyme gene expression by MT under nitrogen deficiency stress condition.