Construction Of Quinoa Regeneration System And Polymorphism Analysis And Content Determination Of ?-aminobutyric Acid Transaminase (GABA-T)

Chenopodium quinoa has rich and comprehensive nutrition,it's "whole-nutrition food".It is of great significance to cultivate high-quality and disease-resistant quinoa varieties and realize germplasm innovation to improve the production and quality of quinoa.Conventional breeding methods can't meet the needs of quinoa production,genetic transformation technology has become an important means for improvement of quinoa varieties,the establishment of an efficient regeneration system is the premise and basis of genetic transformation.Quinoa is a plant that is difficult to regenerate.At present,there are few studies on the in vitro culture and plant regeneration of quinoa,so it is necessary to explore the in vitro culture and plant regeneration conditions of different varieties and explants.This experiment explored the establishment of quinoa regeneration system in order to lay a foundation for the genetic transformation and breeding of quinoa.Gamma-aminobutyric acid(GABA)is an important inhibitory neurotransmitter in animals and a secondary metabolite and signal molecule in plants.Recent studies have shown that GABA may inhibit the expression of Vir gene.It is speculated that GABA may inhibit T-DNA transfer,and the content of GABA may affect the regeneration and transformation system of plants.The activity of GABA transaminase(GABA-T)was closely related to the content of GABA.Because functional gene polymorphism and secondary product metabolism are very important,we analyzed the polymorphism of GABA-T gene,the key enzyme for GABA degradation,and studied its correlation with GABA content.This experiment aims to screen out the varieties of quinoa that are easy to transform,and the results are as follows:(?)research on the regeneration system of quinoa1.Best sterilization method of quinoa seeds: 0.2% hg chloride,5 min.2.Selection of best explants: hypocotyl.3.Optimal conditions for callus induction: 16 h light,8h darkness,temperature(25 ±2)?;0.5 mg/ 2,4-D,0.05 mg/l,6-ba +MS,the highest callus induction rate was above 90%.The hormone ratio is also suitable for secondary culture.4.Six varieties suitable for differentiation: Cq-55?Cq-77?Cq-80?Cq-85?Cq-106?and Cq-300.The callus of Cq-28,Cq-101,Cq-125 and Cq-144 were not good and should not be used for differentiation.5.Differentiation of quinoa callus: there were three differentiation states: green dense type,yellow dense type and pink purple dense type.In 0.25mg/l KT+MS differentiation medium,and the combination of 2,4-D and KT,Cq-77 callus differentiated into more roots.(?)exploration of the relationship between GABA-T and genetic transformation1.GABA-T polymorphism identification: 796 quinoa varieties were tested for polymorphism,and the results showed that GABA-T polymorphism was found in different quinoa varieties.2.Correlation between GABA content and GABA-T gene differences: The gene sequences of the varieties with low GABA content were more different.The structure and function of the GABA-T protein were predicted,which was consistent with the known function.3.Multiple sequence alignment of GABA-T: CqGABA-T3 of quinoa and So GABA-T3 of Spinacia oleracea had the highest homology.Phylogenetic analysis shows that the two species are in the same evolutionary branch and are closely related.4.GABA content analysis of different quinoa varieties: the GABA content of Cq-1712 and Cq-1963 was the least,only containing 7 mg/100 g,while the content of Cq-735 and Cq-2249 was the highest,containing 21 mg/100 g.Cq-1712 and Cq-1963 may be suitable for constructing genetic regeneration system.