The Transcriptome Analyses Between ’Brazilian’ And ’Formosana’ In Response To Banana Fusarium Wilt Stress

Banana wilt disease is a devastating disease for the banana industry.At present,most of banana transcriptome research samples are from seedlings.In the present study,we used RNA-Seq technologies to analyze the banana root transcriptomes of the resistant’Formosana’ and the susceptible strain ’Brazilian’ at the flower bud differentiation stage stressed by Foc4.And we identified the differentially expressed genes between’Formosana’ and ’Brazilian’.Then,quantitative RT-PCR analysis of 10 differentially expressed genes were validated after pathogen infection.And we analyzed the molecular mechanism of fusarium wilt resistance.In this study,we discovered genes of fusarium wilt resistance and enriched banana transcriptome database.Thereby,this study provid a basis for the further elucidation of the mechanism of banana resistant disease.The results are as follows:(1)Our study focused on two banana species,’Brazilian’ and ’Formosana’,at the flower bud differentiation stage.We have obtained 17773064*2 and 20083619*2 pieces of high-quality short Read by RNA-Seq technique,respectively.Through BLAST the banana genome and transcriptome sequences,we found 26917421 and 28353810 genes that matched to the genome banana genome,respectively.By gene annotation,25029 into GO database,9461 into COG database,and 290 into KEGG pathway database.(2)After Comparative analysis of two transcriptomes,there were 107 genes were significantly differentially expressed.Among them,48 genes encoded known proteins.In the 48 known differentially expressed genes,there were 20 genes associated with disease resistance.13 of the 20 genes defense genes related to specific resistance mechanism.(3)We taken banana roots at the flower bud differentiation stage and young as sample.To confirm the results of the RNA-Seq,10 unigenes were selected from those differentially expressed genes for quantitative RT-PCR assays.These unigenes were laccase-4(A)、laccase-4(B)、cellulose synthase catalytic subunit 12、Periplasmic beta-glucosidase precursor、peroxidase N、chitinase、similar to T-phylloplanin、Snakin-1、glutathione-S-transferase Cla47and class Ⅲ peroxidase 136 precursor.Except snakin-1,the expression of the remaining genes in the ’Formosana’ banana at the flower bud differentiation stage was significantly higher than that in ’Brazilian’.qRT PCR analysis of banana at the flower bud stage showed that only laccase-4(A)genes was lower expression in ’Formosa’.The other nine genes were raised.But only five genes in ’Formosana’seedlings was significantly higher than that in ’Brazilian’.Thus,our study shows that the molecular mechanism of the resistant banana strain at flower bud differentiation stage is not completely consistent with experiments when resisitant banana seedlings were at the stress period after inoculated with Foc4.But we need a lot of experiments to confirm this speculation.(4)Preliminary estimate the ’Formosa’disease-resistant mechanism.We analyzed the expression of 10 differentially expressed genes.’Formosa’ directly killed fusarium through the antimicrobial peptide、chitinase,and so on.At the same time,antioxidant enzymes protect plants from ROS.The formation of the structure resistance material prevent the further extension of fusarium.The structure resistance of ’Formosa’was not only enhanced by 10 genes expression,but chemical resistance was also enhanced.When Formosa’infected by Fusarium wilt of banana,the result resistance to Fusarium wilt of banana reaction is synergy effect by polygene.