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 rbcL and accD, 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.
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