GPP

半乳糖-1-磷酸(GPP)

GPP(L-半乳糖-1-磷酸)首先从猕猴桃中分离, 并且GPP蛋白在具有高AsA含量的猕猴桃中以二聚体存在, 但是在具有低含量的苹果中以单体形式存在。然而, 当GPP基因被抑制时, 可以检测到AsA含量和GPP活性, 表明存在其他AsA合成途径或其他具有GPP样催化活性的酶, GPP是唯一一个表达与AsA含量变化一致的基因。因此, GPP的转录调节在调节AsA的合成和蓄积中担当着重要角色。

L-galactose-1-phosphate(GPP)

GPP (L-galactose-1-phosphate) was first isolated from kiwifruit, and GPP protein exists as a dimer in kiwifruit witha high AsA content, but exists in mono-mer form in apple with low content .However, when the GPP gene was suppressed, the AsA content and GPP activity could be detected, indicating that there were other AsA synthesis pathways or other enzymes with GPP-like catalytic activity. In the studies of tomato, apple leaves, and AsA over accumulation mutant lines of Arabidopsis, GPP was the only gene whose expression was consistent with changes in AsA content. Therefore, the transcriptional regulation of GPP plays an important role in regulating the synthesis and accumulation of AsA.