Interdisciplinary Program of Bioenergy and Biomaterials, Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, South Korea.
J Pineal Res. 2013 Aug;55(1):40-5. doi: 10.1111/jpi.12021. Epub 2012 Oct 30.
The regulation of reproduction-stage inducible melatonin biosynthesis in rice (Oryza sativa cv. Dongjin) was investigated. The flag leaf and panicle (flower) were collected from field-grown rice at three different reproductive stages: the preflowering stage, flowering stage, and postflowering stage. Melatonin synthesis was induced in the panicle, whereas no induction was observed in the flag leaf during the reproductive stages. The panicle displayed a peak melatonin level of 0.4 ng/g fresh weight (fw), which was six times that found in the flag leaf. The induction of melatonin biosynthesis was paralleled by the induction of corresponding genes and proteins such as tryptophan decarboxylase, tryptamine 5-hydroxylase, and N-acetylserotonin methyltransferase. In addition, melatonin induction was preceded by the accumulation of its precursor, tryptophan, in the panicle. These results suggest that the induction of melatonin during flower development is regulated by the transcriptional control of its biosynthesis genes and that melatonin may participate in flower development.
我们研究了水稻（Oryza sativa cv. Dongjin）生殖阶段诱导型褪黑素生物合成的调控。从田间生长的水稻的三叶期（旗叶）和抽穗期（花）收集到三个不同生殖阶段的样本：抽穗前阶段、开花阶段和抽穗后阶段。在生殖阶段，褪黑素在穗中被诱导合成，而在旗叶中则没有观察到诱导。穗中褪黑素的峰值水平为 0.4ng/g 鲜重（fw），是旗叶中的六倍。褪黑素生物合成的诱导伴随着相应基因和蛋白质的诱导，如色氨酸脱羧酶、色胺 5-羟化酶和 N-乙酰血清素甲基转移酶。此外，褪黑素的诱导先于其前体色氨酸在穗中的积累。这些结果表明，花发育过程中褪黑素的诱导是由其生物合成基因的转录控制调节的，并且褪黑素可能参与花的发育。
