Mapping Of Major Genes And Bioinformatics Analysis Of Candidate Genes In Tomato Internode Length

Tomato（Solanum lycopersicum L.）is one of the most widely cultivated horticultural crops in the world.Tomato（Solanum lycopersicum L.）is one of the most widely cultivated horticultural crops in the world.With the continuous expansion of the planting area,problems such as shortage of arable land and labor force have become increasingly apparent.The intensive way of raising seedlings increased the density of tomato seedlings,and shaded each other between plants,which promoted leggy growth of seedlings.The shortening of internode length can not only effectively reduce plant height,inhibit leggy growth,increase land utilization,reduce the consumption of nutrients in soil,but also reduce the labor cost of seedling management and fruit harvesting.Significance.At present,the research on internode length mainly focuses on rice,wheat,corn,soybean and other field crops,while the research on the internode length in tomato is very limited.In order to excavate the key genes regulating tomato internode length,two tomato lines with different internode lengths’DH’（normal internode）and’CH’（short internode）were used as experimental materials.Plant hormone metabolomics analysis,hormone response analysis,BSA-seq and candidate gene expression analysis,bioinformatics analysis and other methods were studied.The main results are as follows:1.Measure the internode length of tomato seedling stage from 20 days to 40days.By drawing the growth and development dynamic diagram,it is found that the average internode length of the common internode tomato line’DH’is longer than that of the short internode during the measurement period of the two tomato lines.Tomato line’CH’.By measuring the internode lengths of the 1st to 5th nodes of the two tomato lines at the seedling stage of 40 days,it was found that the lengths of the internodes of the two lines were significantly different,and the lengths of the internodes at the same position were all’DH’Longer than’CH’.The total internode length and average internode length of the two tomato lines during the flowering and fruiting period were compared and analyzed,and it was found that the total internode length of’DH’and’CH’was not significantly different;the average internode length of’DH’was significantly longer than that of’CH’.2.Phytohormone metabolome analysis was carried out on the stems of two tomato lines with different internode lengths at the seedling stage,and a total of 30phytohormones were obtained.Cluster analysis of various hormones between the two tomatoes found that the significantly different hormones in the internodes were indole-3-acetate methyl ester,gibberellin 15,gibberellin 19,5-deoxystrigol.Through the analysis of the metabolic pathways of the differentially metabolized hormones,it was found that the differentially metabolized hormones were mainly enriched in the biosynthesis of indole alkaloids,the biosynthesis of diterpenes,and the biosynthesis of shikimic acid pathway alkaloids,so it was inferred that these three metabolic pathways were involved in the regulation of tomato Internode length plays a key role.By spraying exogenous GA₃ and the gibberellin inhibitor paclobutrazol on two tomato lines with different internode lengths,it was found that the plant height of exogenous GA₃ sprayed increased,and the plant height of paclobutrazol sprayed decreased,indicating that Both tomato lines were able to respond to sprayed exogenous hormones.3.BSA-seq was performed on two tomato lines with different internode lengths,and a total of 137.84 Gb of effective data was obtained.The association analysis of SNP and In Del yielded a 6.14Mb associated region on chromosome 3 with a total of727 genes.In order to mine the key genes involved in the regulation of tomato internode length,the genes in the plant hormone signal transduction pathway and the diterpene biosynthesis pathway were used as entry points,and five differentially expressed genes were screened,namely GA3ox.1,AUX/IAA,and AHP,A-ARR and JAZ.Fluorescence quantitative expression analysis of five candidate genes found that five candidate genes were differentially expressed in the two tomato lines at 25 days and 35 days at seedling stage.4.Bioinformatics analysis of GA3ox.1 gene and fluorescence quantitative analysis of different tissue parts found that the protein encoded by GA3ox.1 gene contains 355 amino acids.Secondary analysis of GA3ox.1 protein found that the secondary structure of the protein is mainly composed of It is composed of 4 forms:α-helix（31.27%）,extended chain（16.06%）,β-turn（6.48%）and random coil（46.20%）;the homology comparison analysis shows that the GA3ox.1 protein has a homology relationship with potato Recently,the spatiotemporal expression analysis of GA3ox.1 found that the expression levels were different in the roots,stems and leaves of the two tomato lines.The relative expression level was the highest in leaves,followed by roots,and the lowest expression was in stems.