The Functional Study Of Brassica Napus BnNF-YB2/3/4/5/6 Under Flowering Regulation And Abiotic Stress In Arabidopsis

Salinization of soil is one of environmental problems and is also one of the key factors restricting the growth of plant."Nanyanyou 1"(Brassica napus)is widly planted in the coastal shoal of Jiangsu Province in China.This thesis mainly aims at studying the biological function of several NF-Ys(NUCLEAR FACROR Y),BnNF-YB2,BnNF-YB3,BnNF-YB4,BnNF-YB5 and BnNF-YB6(BnNF YB2/3/4/5/6).NF-Yis an important nuclear transcriptional factor.It was reported that NF-Y has various biological functions in plant,such as flowering regulation,stress response,the development of root nodules,embryonic development,chloroplast synthesis,fatty acid metabolism and so on.The main results are as follows:Phylogenetic tree and amino acid sequence alignment were both constructed for BnNF-YB2/3/4/5/6 of Brassica napus by MEGA 6.0 and ClastalW,respectively.The result of phylogenetic tree analysis revealed that BnNF-YB2/3 with AtNF-YB2 and BnNF YB4/5/6 with AtNF-YB3 had higher similarity,respectively.For flowering regulation experiment under the condition of long-light(L/D,18 h/6 h)the results found that BnNF-YB2/3/4/5/6 could promote flowering in transgenic Arabidopsis compared with WT.Through Real-time quantitative expression analysis of genes(CO,FT,SOC1 and LFY)involved in photoperiod regulation pathway in various tissue at different stages under the condition of long light(L/D,18h/6 h),the result showed that the expression level of FT,SOC1 and LFY were significantly increased compared with WT,but that of CO still kept constant.For physiological assay under different conditions of stress(CK,75mM Nac,100mM Nacl,50mM mannitol,100mM mannitol,0.1uM ABA)in transgenic Arabidopsis and WT,respectively,the results revealed that BnNF-YB2/3/4/5/6 could increase the length and the number of roots of Arabidopsis,compared with WT under normal and stress condition,respectively.Subcellular localization experiment assey(GFP fusion protein)revealed that BnNF-YB2/3/4/5/6 were all located in nucleus of root tip cell in arabidopsis.GUS-promoter positioning experiment analysis showed that BnNF-YB2/3/4/5/6 are detected in leaf tissue at seedling stage of Arabidopsis,especially in the shoot apical meristem(SAM).