Preliminary Analysis Of Disease Resistance Pathway Regulated By MeERFs Transcription Factors In Cassava

Transcription factors play an important role in the response of plants to stress is the main regulator of plant response to biotic and abiotic stresses.Ethylene and disease can cause the expression of ERF transcription factors.Most of them will be combined with the cis acting element GCC-box in the downstream gene promoter region to regulate gene expression,while GCC-box generally appears in many promoter regions of PR protein.cassava(Manihot esculenta Crantz)is not only an important food crop in the tropics,but also an important economic and energy crop.However,cassava bacterial blight(CBB)always restricts cassava production.Therefore,it is of great significance to study the role of ERF transcription factors in the infection of Xam.In this study,South China 8 cassava was used as experimental material to clone six ERF family genes,and the functions of the six candidate genes were preliminarily studied by expression pattern analysis,subcellular localization,transcriptional self-activation activity analysis,VIGS and other technologies.The main experimental results are as follows:1.Bioinformatics analysis showed that six MeERFs were distributed on different chromosomes of cassava,and all of them contained only one exon.Promoter prediction analysis: the promoter regions of MeERF08,MeERF33,MeERF56,MeERF113,MeERF133 and MeERF138 contain a large number of light response elements and a variety of defense and stress response elements(TC rich Repeat);tissue-specific analysis: MeERF08,MeERF33,MeERF56,MeERF113,MeERF133 and MeERF138 all showed higher transcription abundance(FPKM > 10)in the roots of cassava cultivar W14,but generally lower in the leaves;expression pattern analysis under pathogen infection: MeERF08,MeERF33,MeERF56,MeERF113,MeERF133 and MeERF138 transcription factors were all strong MeERF08,MeERF33 and MeERF133 were the three transcription factors most significantly inhibited by the pathogenic strain.2.The effect of MeERFs on disease resistance of cassava was analyzed by VIGS system.The results showed that MeERFs08 had poor silencing effect,and other MeERFs could be effectively silenced.The water spot diffusion area and brown spot area of pyy13-MeERF33 and pyy13-MeERF113 were smaller than those of wild type,and the disease resistance of the silenced plants was significantly enhanced;pyy13-MeERF56,pyy13-MeERF133 and pyy13-MeERF138 showed larger areas of water spots and brown spots in the silenced plants than those in the wild type,and the disease resistance of the silenced plants decreased significantly.3.The results of subcellular localization showed that MeERF113 was localized in the nucleus,MeERF08,MeERF33 and MeERF138 were expressed in the nucleus and cell membrane,and MeERF56 was expressed in the nucleus,cell membrane and cytoplasm.4.The results showed that MeERF33 and MeERF56 had no transcriptional activity,MeERF113 and MeERF133 had strong transcriptional activity,while MeERF08 and MeERF138 had weak transcriptional activity.5.The interaction of MeMAPKs and MeERFs transcription factors was analyzed by yeast point-to-point technology,and two pairs of possible interaction proteins were screened.MeMAPK2 and MeMAPK8 interacted with MeERF33 respectively.6.Analysis of chromosome location distribution of target genes downstream of MeERFs: it is distributed on 18 chromosomes of cassava;analysis of expression mode of pathogenic bacteria infection: 26 genes can be induced and expressed by strong pathogenic bacteria and inhibited by weak pathogenic bacteria.7.Double Luciferase Report system was used to study the regulatory relationship between MeERFs transcription factor and downstream target genes Manes.02G024800 and Manes.18G073800: MeERF08 and MeERF56 positively regulated Manes.02G024800;MeERF133 negatively regulated Manes.02G024800;the regulatory relationship between MeERFs transcription factor and Manes.18G073800 needs further study.