Transformation Of CYP83A1 And CYP83B1 And Effects Of Exogenous Sulfur On Glucosinolate Synthesis In Pakchoi

Glucosinolates ?GSs? are a group of the important secondary metabolites rich in nitrogen and sulfur, mainly found in cruciferous plants. GSs have been proved to have strong relations with Brassica vegetable's defense system. GSs also have beneficial effects on human health. Modifying the GS profiles and concentrations by genetic engineering and other factor, to get more beneficial GS for human health, or to promote the capacity of plant defense to external stress, has become a research hotspot in recent years. In order to improve the nutritional quality and strengthen the function of vegetables and plant defense, it is really important to study the effect of exogenous substance on plant GSs synthesis.Pakchoi ?Brassica campestris L. ssp. chinensis var. communis Tsen et Lee?, a traditional cruciferous vegeyable originated from China, is widely grown in the south of China. Pakchoi is a kind of people's favorite vegetable for rich in nutrition, which has short growth period and easy to cultivate.CYP83A1 and CYP83B1 are two key genes for the synthesis of core structure of GSs. The content of GSs can be regulated by those gens. In this research the expression and function of CYP83A1 and CYP83B1 were analyzed by the genetic transformation in Pakchoi. We also had studied the effects which are about the content of metabolite and mineral element and the expression of genes of GSs synthesis when we had treated the Pakchoi in different sulphur treatments.The major results were as follows:?1?The gene fragment which is related to CYP83A1 and CYP83B1 were cloned from'YOUQING 49' according the Brassica Database in NCBI. The antisense expression vector,pBI121-AntiCYP83A1 and pBI121-AntiCYP83B1, were constructed and authenticated.?2?The antisense expression, pBI121-AntiCYP83Bl, was introduced into pakchoi by agrobctterium-mediated method. The plant transformed was authenticated by PCR and the expression of CYP83A1 and CYP83B1 was analyzed by qRT-PCR in transformation plant. Finally,four Pakchoi were obtained, those Pakchoi all have contained pBI121-AntiCYP83B1.?3?The effects of different sources ?Na₂SO₄, NaHSO₃ and NaHS? and concentrations ?1.0,10 mM? of sulphur on metabolite and chemical element contents and GSs synthesis genes expression were studied in Pakchoi. The results shown that high concentrations of NaHS could significantly increase the content of glutathione, and the three kinds of high concentrations of sulfur could significantly increase the content of isoleucine. Meanwhile, CYP83A1 and CYP83B1, have been obviously affected. The expression of CYP83A1 and CYP83B1 can be improved by treatments in 3 hours, which might be one of the reasons that sulfur could increase the content of GSs.The results of the study would provide useful reference for future researches on GSs in pakchoi.