Physiological roles of tryptophan decarboxylase revealed by overexpression of SlTDC1 in tomato
Physiological roles of tryptophan decarboxylase revealed by overexpression of SlTDC1 in tomato
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DOI：
10.1016/j.scienta.2020.109672
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发表时间：
2021-01
影响因子：
4.3
通讯作者：
Y. Tsunoda;Shohei Hano;Nozomi Imoto;T. Shibuya;Hiroki Ikeda;Kayoko Amagaya;K. Kato;H. Shirakawa-H.-S
中科院分区：
文献类型：
--
作者：
Y. Tsunoda;Shohei Hano;Nozomi Imoto;T. Shibuya;Hiroki Ikeda;Kayoko Amagaya;K. Kato;H. Shirakawa-H.-S
SlTDC1是番茄中色氨酸脱羧酶（TDC）的候选基因，是本研究的重点，因为SlTDC1可能在血清素的生物合成中发挥作用（Hano et al., 2017），血清素因其抗肥胖作用而成为一种新的功能成分；此外，它的发育作用在很大程度上是未知的。用sltdc1 （TDX系）转化番茄，研究其酶促功能、sltdc1和血清素的发育作用以及分子育种的可能性。转化使果实血清素浓度增加3倍或更多，而无生长抑制；相反，作为血清素生物合成底物的色氨酸的浓度下降。结果表明，sltdc1在生产富含血清素的水果中的作用及其实用性。此外，我们的转基因研究表明，色胺5-羟化酶可能是5-羟色胺生物合成的关键酶。在TDX系中观察到卷曲的叶缘，这可能是色氨酸浓度降低的结果。经5 -羟色胺处理的TDX果实和野生型果实从开花到破环成熟期的天数减少，实时荧光定量PCR和rna -测序结果显示，TDX果实中成熟相关基因的表达增加，表明5 -羟色胺在成熟过程中发挥了作用。总的来说，我们的研究结果揭示了TDC在水果中的园艺重要性及其生化和生理作用。
SlTDC1, a candidate gene for tryptophan decarboxylase (TDC) in tomato, was the focus of this study becauseSlTDC1may play a role in the biosynthesis of serotonin (Hano et al., 2017), which is a novel functional ingredient because of its anti-obesity effects; further, its developmental roles are largely unknown. Tomato was transformed withSlTDC1(TDX lines) to demonstrate its enzymatic function, the developmental roles ofSlTDC1and serotonin, and the possibility of molecular breeding. Transformation increased serotonin concentration three times or more in fruit without growth inhibition; in contrast, the concentration of tryptophan, which is the substrate of serotonin biosynthesis, decreased. The results showed the roles ofSlTDC1and its usefulness in producing serotonin-rich fruits. In addition, our transgenic studies indicated that tryptamine 5-hydroxylase might be a key enzyme in serotonin biosynthesis. Curling leaf margins were observed in TDX lines, which may result from a decrease in tryptophan concentration. The number of days from flowering to the breaker ripening stage decreased in TDX fruit and wild-type fruit treated with serotonin, and the expression of ripening-related genes was promoted in TDX fruit in real-time PCR and RNA-sequencing analyses, indicating the role of serotonin in ripening. Collectively, our results revealed the horticultural importance of TDC in fruit with its biochemical and physiological roles.