The Functional Analysis Of The Stress Tolerance Of Transcription Factor NF-Y In Rapeseed (Brassica Napus L.) And Transcriptome Analysis Under Abiotic Stress

There are abundant tidal flat resources in our country.However,because of the long-term effects of abiotic stress(salinity and drought),plants can not grow on the beach,which ultimately leads to the inadequate use of beach resources.Brassica napus L.,an important oil crop,has strong adaptability to environment through gene regulation during its growth and development under biotic or abiotic stresses.NF-Y is a nuclear transcription factor,which involves in the regulation of flowering time,legume nodule,photosynthesis and stress tolerance.In this study,we want to determine NF-Ys or other genes’ function from salinity-resistant rapeseed,which could improve tolerance of our canola.Finally,we can also make full use of beach resources.The main results were as follows:1.AtNF-Ys of Arabidopsis thaliana were BLASTNed to the newly sequenced genome database of Brassica napus L..Taking the cDNA and genomic DNA as the template respectively,we finally identified 9 new BnNF-YAs,6 new BnNF-YBs and 5 new BnNF-YCs.qRT-PCR was used to analyze the expression of these members under simulated stress.It was found that all of these new NF-Ys were up-regulated when treated with PEG,but only some of them could respond to ABA and NaCl.2.In our previous experiments,it has been proven that BnNF-YA9 is a member of NF-Y family which can increase the resistace ability of canola.Therefore,we will continue to study its stress tolerance mechanism in this study.In order to screen interaction partners of BnNF-YA9,the bait vector pGBKT7-BnNF-YA9 was constructed.The results showed that the bait plasmid had no toxicity to Y2H Gold yeast cells,and also had no self-activation.In the cDNA library of canola under stress treatments,we screened 31 possible interaction partners.Then the yeast plasmids were extracted and further verified by one-to-one interaction,and 22 real candidates were finally confirmed.We eventually analyzed the domains of those protein and browsed the related literature,then BnTSB,BnERD15 and BnFD would be selected for the further verification.3.In order to accquire more stress-resistant genes,transcriptome technique was performed on canola under PEG or NaCl treatment.The analysis of DEGs showed that there were much more DEGs under PEG treatment than those under NaCl treatment.We also found that plants up-regulated genes in roots to respond to drought stress,while down-regulated genes in roots to respond to salt stress.Analysis of transcription factors showed that MYB family,AP2/EREBP family and NAC family accounted for a large proportion under abiotic stress.Many reports showed that these families could respond to abiotic stress and therfore could be used as candidate genes.In addition,physiological and biochemical indexes of canola under stress treatment were also measured.Among them,the change of proline content was mostly obvious.By analyzing the proline metabolic pathway,it was found that plants accumulate proline mainly by increasing the expression of related genes in proline synthesis pathway and reducing the expression of genes in proline degradation pathway.