Potential new enzymes in plant NO biosynthesis

本项目旨在确定多胺诱导的一氧化氮（NO）的源酶。多胺诱导的NO合成是在PI的实验室中发现的，并且是前所未有的。与已发表的关于植物NO合成酶的信息相反，外源精氨酸在诱导快速NO合成方面不如多胺（腐胺、精胺、亚精胺）有效。由于多胺对NO合成的诱导非常迅速，这表明可能已知的植物NO生物合成酶或用于NO生物合成的新酶群使用多胺作为底物。搜索将包括已知的AtNOS基因家族和多胺氧化酶基因家族。鉴定的蛋白质将被重组纯化并作为NO合酶进行测试，并在拟南芥中在化学控制的启动子下表达，从而可以证明NO生物合成和表型的变化。由于多胺在植物中具有广泛的生理意义，本项目将为植物多胺生物学研究提供新的基础。

This project aims at identifying the source enzyme(s) of polyamine-induced nitric oxide (NO). Polyamine-induced NO synthesis was discovered in the lab of the PI and is unprecedented. In contrast to published information about plant NO synthesizing enzymes, exogenous arginine is less effective than polyamines (putrescine, spermine, spermidine) in inducing rapid NO biosynthesis. As polyamine induction of NO synthesis is very rapid this indicates that perhaps known enzymes of plant NO biosynthesis or a new enzyme group for NO biosynthesis use polyamines as a substrate. The search will encompass the known AtNOS gene family and the polyamine oxidase gene family. The protein identified will be recombinantly purified and tested as a NO synthase and expressed under a chemically controlled promoter in Arabidopsis so that changes in NO biosynthesis and phenotype can be demonstrated. As polyamines have a wide-spread physiological significance in plants the project will give a new foundation to polyamine biology in plants.