Study On The Function Of StAN1 Gene And StCHS Gene Of Colored Potatoes In Anthocyanin Synthesis,Heat And Drought Tolerance

Anthocyanin is an important secondary metabolic substance in plants,playing a significant role in plant pollination and resisting external non-biological stress,while rich in anthocyanin can help people have effectively prevent cancer,cardiovascular,cerebrovascular,hypertension and the occurrence of diabetes.Colored potatoes can meet people’s intake of anthocyanin and supplements in the amount of staple food.During the synthesis of anthocyanin,the light plays a key role.The leaf is an important photosensitive organ of the plant.The colored potato leaves are also anthocyanin synthesis and accumulated organs,which can be transferred to other tissue parts to store.At present,there are few studies on the synthesis and regulation of anthocyanins in colored potato leavesIn this study,the third generation nucleic acid sequencing technology was used to sequence the transcriptome of Shepody,Red R3 and Purple R2,to improve the regulatory mechanism of anthocyanin synthesis and accumulation in colored potato leaves.Clustering analysis was carried out on the differences between the transcript,database annotations,mining with colorful potato leaf in the structure of the anthocyanin synthesis pathway related genes and transcription factors.Subcellular localization of related gene St CHS and construction of overexpression material,as well as related transcription factor StAN1 transgenic tobacco were subjected to drought and high temperature stress.Physiological indexes such as malondialdehyde and the expression levels of stress resistance genes LEA and ERF were determined.In order to provide a theoretical basis for the molecular mechanism and regulation mechanism of anthocyanin synthesis in colored potato and the molecular breeding of potato stress resistance.Through the above research,the results are as follows:(1)Analyze the results of transcriptome data and improve the annotation information of potato database.4925 differentially expressed transcripts were detected in the three potato leaves,and multiple genes and transcription factors related to the pathway of flavonoid metabolism and anthocyanin synthesis were identified.It was also found that there were fusion transcripts and alternative splicing of m RNA in the anthocyanin metabolic pathway of Red Rose 3 and Purple Rose 2,which directly affected the expression of genes related to anthocyanin synthesis.(2)Based on the transcriptome sequencing result,differentially expressed genes related to ways of anthocyanin synthetase chalcone St CHS gene cloning research,in the colored potatoes on the gene cloning,the comparison of different color in the potato,after the sequence of the gene encoding protein highly conservative,only a single amino acid difference.The result of subcellular localization indicated the protein expressed by this gene was expressed in the cell nucleus and cell membrane.After analyzing the overexpressed St CHS gene material,it was found that the St CHS gene cloned in this study had less significant regulation effect on anthocyanins than the transcription factor StAN1.(3)The positive rate of transgenic tobacco was 83%,and the expression level of StAN1 in different transgenic tobacco was 17.3 times higher than wild type on average.Transgenic identification and q RT-PCR detection were carried out to ensure the successful transfer and expression of gene.Comparison of total anthocyanin content between transgenic tobacco and wild-type tobacco showed that the content of anthocyanin in the over-expressed StAN1 gene was 4.8 times than the wild-type tobacco.(4)In order to further study whether StAN1 gene can improve the ability of plants to scavenging reactive oxygen species by increasing anthocyanin content,thus enhance the regulation of plant tolerance to abiotic stress.The StAN1 transgenic tobacco was treated with drought and heat stress in this study.When mannitol concentration for 150 mmol/L,transgenic tobacco seed germination rate is significantly higher than wild type tobacco.After drought stress treatment,superoxide dismutase(SOD)activity and proline content of transgenic tobacco seedlings were 1.6 times and 2.1 times than wild-type tobacco seedlings at the 9th day,and the expression levels of ERF and LEA genes in response to stress were also significantly up-regulated.These results indicated that StAN1 gene could promote anthocyanin synthesis and improve the tolerance of plants to drought and heat stress.The above experiments showed that the St CHS gene cloned in this experiment has no obvious regulatory effect on anthocyanins,while the StAN1 gene participates in the pathway of anthocyanin regulation,which significantly increased the content of plant anthocyanins and can enhance plant tolerance to drought and high temperature.