Expression Characteristics Of Candidate Genes For Plant Architecture Regulation Of Salix Psammophila In The Population

In this study,a prediction population,a training population and a validation population were constructed based on the plant characteristics values(crown height ratio)using S.psammophila asexual lines as research materials.The genetic screening was carried out using a combination of RNA-seq and RT-q PCR analysis,using the correlation coefficient between FPKM values and plant architecture characteristics in the sequencing results as predictive values and the results reported by previous authors,and validated in the training and validation populations.The best gene combinations related to plant architecture characteristics were screened by genomic legitimacy,and the candidate gene mining techniques for S.psammophila plant architecture were explored.The results showed that:(1)A total of 40,049 genes were detected by transcriptome sequencing of the predicted population,with 37,865 known genes and 2,184 unknown genes.The predicted values of different genes varied from 0.0 to 0.9.The focus was on GO and KEGG enrichment analysis of differential genes in shoot stems,which involved the pathways of phytohormone signaling,biosynthesis of secondary metabolites,and metabolism.(2)RT-q PCR in the training population revealed that the correlation coefficients of target gene expression and crown height ratio in the young stem and stem tip had the same trend as the predicted values,and the correlation coefficients in the young stem were closer to the predicted values.The correlation coefficients of FHY1,ATX1 and RFK1 genes,which had larger predicted values,were also larger in the training population,while the predicted values of LAZY1 b and TAC2 genes were smaller and the correlation coefficients in the training population were also smaller.(3)Using the young stem as the sampling site,the correlation between gene expression and crown height ratio in the hydroponic validation population and field validation population were consistent with the predicted population during the growth period.the correlation coefficients were larger for FHY1,ATX1,and RFK1,and smaller for LAZY1 b and TAC2 genes.the expression of ATX1,FHY1,PYL1,RFK1,SPA2,and TB1 genes increased with the temperature decreased.(4)The validation population was subjected to transcriptome sequencing,and it was found that FHY1,ATX1,and RFK1 were highly correlated with the crown height ratio in both the hydroponic or field populations,and FHY1 and TAC2 were positively correlated,while the rest of the target genes were negatively correlated;the expression of ATX1,RFK1,FHY1,SPA2,PYL1,and TB1 increased with decreasing temperature,and the expression of ATX1,FHY1,SPA2,ZFP4,and TB1 was significantly greater in the hydroponic population than in the field population;the target genes with high gene expression in the predicted population were equally expressed in the validation population.(5)The two-gene combination(ATX1+FHY1)was used as the best gene combination to identify the plant architecture of S.psammophila according to the principle of "the lowest number of genes and the highest correlation coefficient",and the correlation coefficient between this gene combination and crown height ratio was 0.74.The use of morphology and transcriptomics as a whole to mine genes related to plant architecture traits is a characteristic of this study,and the use of traits and related genes to establish the screening of back-up genes for S.psammophila plant architecture is an innovation of this study.The method removes the complicated transgenic technology,accelerates the efficiency of forest tree breeding and improves the selection accuracy of the back-up genes.