Analysis Of Volatile Components And Expression Of Flower Scent Synthase Gene RhNUDX1 In Rosa L.

Germplasm resources of Rosa L.widely distribute all over the world,they have an important ornamental,edible and medicinal value.As one of the important ornamental characters of plants,flower scent not only plays an important role in reproduction,but also can improve the ornamental and economic value.Due to the limitation of traditional cross breeding and the focus of breeding experts on flower shape and colors,most modern roses do not have obvious scent.Currently,due to the demand of market,the genetics breeding on rose scent research will prove to be an important direction.Based on this situation,firstly,we analyzed the differences of flower scent components and releases among main germplasm resources of Rosa L.to explore the changes of scent substances in rose during long-term breeding.On this basis,the expression and structural differences of RhNUDXl,a key flower scent related enzyme gene,were further analyzed in different materials.The main results are as follows:1.The differences of flower scent components of petals at blooming stage in 50 samples of Rosa L.were analyzed by Headspace Solid-Phase Micro extraction and gas chromatography-mass spectrometry.The results showed that all samples detected mainly contain alcohols,terpenes and aromatic hydrocarbons.The main components of flower scent and the amount of release have changed in different varieties,they show 9 common components,such as geraniol,citronellol,phenylethanol,4-methoxystyrene,cadinene,3,5-dimethoxytoluene.In addition,the wild resources also include benzyl alcohol,eugenol methyl ether and so on.Old garden rose also include citral and octadiene.Modern rose includes ionone and theaspirane.2.The gene expression of RhNUDXl in 38 different samples was analyzed by real-time fluorescent quantitative PCR.The results showed that the amount of geraniol released was related to the gene expression level of RhNUDX1 in 33 samples.It was verified that RhNUDXl gene was involved in the release of geraniol,was the key synthase gene in rose scent metabolism pathway.At the same time,the expression of RhNUDX1 gene in 5 samples was not correlated with the amount of geraniol released.3.The genomic sequence of RhNUDXl was cloned from R.chinensis’Old Blush’and R.multiflora Thunb.The results showed that the genomic sequence of RhNUDXl in R.cheninsis’Old Blush’ and R.multiflora Thunb.was different,especially in four amino acids,which may contributed to the inability of RhNUDXl gene expression in R.multiflora Thunb.