Physiological Characteristic And Transcriptome Analysis Of Etiolation In Paulownia

PFE(Paulownia fortunei etiolation)was screened from PF(Paulownia fortunei)hybrid seedings.Before the study of leaf color mutant there was no living specimens had been found,so no research reported about it.After years of breeding,its leaves and stems are yellow,significantly different from normal Paulownia and its specific traits can be stable.Its formation mechanism,physiological characteristics and molecular mechanism during growing were not clear.Therefore,in this study,the physiological characteristics and transcriptome information were studied by using PFE and other breeds.Using a newly discovered Paulownia fortunei etiolation Mutant(PFE)and Paulownia fortunei(PF)、Paulownia jianshiensis(PJ)、Paulownia catalpifolia(PC)as research objects,analyzing their photosynthetic pigment content 、 photosynthetic diurnal changes、autioxidant enzyme activities and MDA content.The results showed that etiolation mutant of chlorophyll a,chlorophyll b,total chlorophyll,and carotenoids in the mutant were reduced,chlorophyll b decreased most.The diurnal variation of photosynthetic rate(Pn)and the transpiration rate(Tr)of etiolation mutant were less than other varieties;The difference of stomatal conductance value was small,and the overall change of intercellular CO2 concentration was higher than that of other varieties.The activity of antioxidant enzyme and the content of MDA showed that SOD,POD,CAT activities and molality of malondialdehyde(MDA)of etiolation mutant were higher than other varieties.We generated about18.15 Gb data in total about PF1,PF2,PFE1,PFE2 after Illumina Hiseq sequencing in total.Then assembling all samples together,we got81610 Unigenes,the total length,average length,N50 length of Unigenes were101727851 bp,1246bp,2014 bp.When Unigenes were annotated with 7 functional databases,about76.68%(62575)Unigenes can be annotated in at least one of the functional database.Annotating Unigenes with Nr database,most unigenes can be matched with the species of Sesamum indicum.5702 unigenes can be annotated to 52 functional categories of GO database,24062 unigenes can be annotated to 25 proteins of COG,42185 unigenes can be annotated to 21 pathways of KEGG database.Withfunctional annotation results,we detected 56710 CDS in total.Unigenes can encoding58 family of transcription factors,most of unigenes which are MYB、MYM-related、C3H 、 b HLH and AP2-EREBP.We detected 5011 SSR,most of them were mono-nucleotide to trinucleotide detected and Quad-nucleotide to Hexa-nucleotide were less.207273 SNP were detected,the number of SNP in PF was more than PFE,the number of transition was more than transversion.According to the results of gene expression,we detected 1664 DEGs between PF and PFE,817 up regulated,847 down regulated genes.Annotating 672 DEGs to 34 functions of GO database,the Unigene mostly were involved in catalytic activity、binding、metabolic process and cellular process.1146 DEGs can be annotated to 122 metabolic process or pathways,5 pathways were related to chlorophyll metabolism,the synthesis and degradation of chlorophyll were influenced by 21 DEGs.They were orthology to LCHA2、psa L、Psb R、CHLP、AAO3 and so on.Carotenoid biosynthesis related genes were up regulated.