Identification And Expression Analysis Of Gene Related To Flowering In Anthurium

Flowering time is a very important objective trait in ornamental plant breeding.Adult Anthurium flowers all year around,but there is an obvious difference in flowering rate and the time from test-tube seedling to flowering between different cultivars.Therefore,it is of great significance to study molecular mechanism of flowering in order to promote the development of breeding and industry in Anthurium,and it can also provide a reference value to better understand the flowering mechanism and genetic modification of flowering phase in other ornamental plant.In this study,the formation and development process of inflorescence in the Anthurium ‘fengyun' was observed,genes related to flowering were screened through RNA-Seq and analysis,and key flowering genes were identified by the use of qRT-PCR technology.The main results include the following points:1.The formation and development stage of leaf and inflorescence in Anthurium According to the result of observation,the formation and development process of inflorescence in Anthurium ‘fengyun' was divided into seven stages including the inflorescence induction stage,inflorescence differentiation stage,floret primordium formation stage,spathe breakthrough stage,spathe pigmentation stage,pedicel elongation stage and spathe unfolding stage.The formation and development of leaf was divided the leaf induction stage,leaf differentiation stage,leaf formation stage,leaf pigmentation stage,petiole elongation stage,leaf breakthrough stage and leaf unfolding stage.2.RNA-Seq analysis of in Anthurium ‘fengyun' 98644 unigenes were obtained,with the longest length being 16765 bp,the shortest length being 201 bp and the average length being 839 bp.Of them,10254 were annotated,accounting for 10.39% of the total genes.There were 10692 differential expressed genes(DEGs),among which,6266 DEGs existed in L1-VS-B1,3885 appeared in L2-VS-B2.There were 3460 DEGs between inflorescence differentiation and floret primordium formation stage.197 DEGs existed in L1-VS-B1,L2-VS-B2 and B1-VS-B2.3.Analysis of KEGG and GO KEGG enrichment analysis showed that the DEGs of L1-VS-B1 significantly mainly enriched in peroxisome,cutin,suberine and wax biosynthesis,sulfur metabolism,other glycan degradation,amino acids,phenylalanine,tyrosine and tryptophan biosynthesis pathway,while those in L2-VS-B2 significantly mainly enriched in carbon metabolism,sulfur metabolism,other glycan degradation,pentose phosphate pathway and glycolysis / gluconeogenesis.DEGs of B1-VS-B2 significantly mainly enriched in cutin,suberine and wax biosynthesis,peroxisome and ribosome pathway.GO enrichment indicated that DEGs of L1-VS-B1 and L2-VS-B2 were enriched in the GO terms of metabolic process,cellular process,single-organism process and localization,while those in B1-VS-B2 were enriched the in GO terms of metabolic process,single-organism process and localization.4.Screen of gene related to flowering in Anthurium 92 genes related to flowering were obtained through local blastx in Anthurium,among which,there was 30 genes in photoperiod and circadian rhythms pathway,27 in floral integrator pathway,11 in GA pathway,9 in vernalization pathway,11 in autonomous pathway and 4 in aging pathway.5.Selection of reference gene.Among TUB,GADPH,ACTB and EF1 a genes,TUB was suitable for being as a reference gene in gene expression analysis in different tissues in Anthurium ‘fengyun',and GADPH was suitable for being as a reference gene in leaf and stem of different cultivars.6.Expression of COP1,PEP,FPA and FLC in leaf of flowering plant The relative expression level of FPA gene in the late flowering type was higher than that in early flowering type.The relative expression level of FLC gene was low except in ‘fengyun'.The relative expression level of COP1 and PEP was higher in late flowering type compared with in early flowering type and intermediate flowering type.7.Expression of COP1,PEP,FPA and FLC genes in Anthurium ‘fengyun' COP1 and FLC gene highly expressed in stem,and the level expression was highest in the sixth month after transplantation,the lowest expression appeared in the tenth month.The expression level of PEP gene was the highest in stem or root in the sixth or the eighth month after transplantation,and the lowest in stem at initial flowering stage or in root in the seventh month.FPA gene highly expressed in stem,and the expression level was the highest in the sixth month and the lowest in the seven month.Through the above research,the formation and development stage of leaf and inflorescence and their transcriptome differences in Anthurium ‘fengyun' were clarified,genes related to the length of juvenile stage were identified,which lay a foundation for further elucidating molecular mechanism of flowering all year around and genetic improvement of flowering time in Anthurium in future.