Analysis Of Differential Expression Genes Assosiated To Starch Metabolism Enzyme Of Yam(Dioscoreaopposite Thunb.) Tuber And Cloning Of BAM1 Gene

Dioscorea opposita tuber is the main factor to measure the quality and yield of yam.Yam is a cash crop with great market prospects and industrial development potential.The research on its yield and quality has attracted more and more attention from scholars at home and abroad.The accumulation and metabolism of starch in tuber is important factor affecting the yield of yam and the quality of tuber.In this study,Bikeqi yam tuber was selected as experimental materials,the content of starch in tuber,the enzyme activity related to starch metabolism and the expression of enzyme gene were determined,and the regularity of starch metabolism in tuber of yam was analyzed,and the candidate genes which played a key role in starch metabolism of yam were provided.The cDNA length of starch metabolism related enzyme ?-amylase gene BAM 1 was cloned by RACE technique and analyzed by bioinformatics.The full-length gDNA of BAM 1 gene was cloned by RT-PCR technology.Bikeqi yam and Dahechangyu yam with significant differences in starch content as experimental materials,and qRT-PCR technology was used to compare the expression difference of BAM 1 gene during yam tuber expansion.Based on the study of ?-amylase gene BAM 1,the degradation process of starch during tuber expansion of yam was analyzed to provide some theoretical basis for exploring tuber expansion of yam.The main findings are as follows:(1)The starch content of Bikeqi yam showed a rising trend and then a decreasing trend,reaching a maximum value at 135 days,and the starch content accounted for 87.44%of the dry weight.The change trend of amylose and amylopectin was similar to that of total starch content.After 135 days,the ratio of amylopectin to amylose content decreased.(2)AMY,ADPGase,SSS,and SPS all play important roles in the starch metabolism pathway.ADPGase plays an important role in the synthesis of starch and amylose,SSS is very positively correlated with amylopectin,which regulates amylopectin synthesis.Isoamylase3 and SPS1 were significantly negatively correlated with starch content and played an important regulatory role in starch decomposition.Starch synthase 3 and Isoamylase 3 have a significant or very significant negative correlation with amylopectin content,which negatively affects amylope(?)in synthesis.(3)The full-length cDNA sequence of ?-amylase gene BAM 1 was cloned from Bikeqi Yam.The gene was 2863bp in length,containing a complete Coding sequence(CDS),1629 bp in length,5 ' untranslated region was 1148 bp in length,3' untranslated region is 42bp in length.(4)The CDS sequence of yam BAM 1 was cloned,encoding 543 amino acids,and the theoretical molecular weight of protein was 622.92 kD,and the isoelectric point was 5.60.Predicting their subcellular localization in mitochondria,A phylogenetic analysis of amino acid sequences of BAM 1 genes in 10 plants,such as yam and oil palm,showed that the relationship between yam and cypress was the most recent and the most distant relationship with grape.The BAM 1 gDNA full-length sequence was cloned with a length of 3422 bp,and the alignment with the cDNA encoded sequence showed that the gDNA consisted of six exons and five introns.(5)Analysis of the expression of BAM 1 showed that the gene expression level of BAM 1 in Dahechangyu yam with high ?-amylase activity was significantly higher than that of Bikeqi yam with low ?-amylase activity.And there was a very significant positive correlation between ?-amylase activity and the expression level of BAM 1 gene in Dahechangyu yam.BAM 1 the same gene during the expansion period,there were specific differential expression between different organs.