Optimization Of Soybean Transformation System And Transferring GmPDR12 Gene Into Soybean And Effects Of Aluminum Stress On Gene Expression In Leaves Of Different Soybean Genotypes

Acid soil(pH<5.5)is one of the most important limiting factors for agricultural production worldwide.About 30%of the world’s land area is acidic soil,and 40%of the soil area that can be used for farming is acidic too.In acidic soilsat pHbelow 5.0,the prevalent aluminum(Al)species is Al(H2O)63+(abbreviated as Al3+)which inhibits plant growth and developmentand result in crop yield reduction significantly.In recent years,the mechanism of plant resistance to Al stress,especially the molecular mechanism study has made some important progress,and many gene families with Al-resistant functionhave been identified.In our previous study,the GmPDR12 gene which encodes and ABC transporter protein,was found to be an Alresistant candidate.,In order to characterize the function of GmPDR12 furthermore,in this experiment,soybean cultivar BD2 and Jack were used as the genetic transformation acceptors.Firstly,we optimized the Agrobacterium tumefacienmediated genetic transformation system based soybean cotyledonary nodes.Transformation events in a screened herbicide resistant soybean Jack plant were confirmed using PCR analysis,which indicated that the chimeic GmPDR12-eGFP gene has been successfully integrated into the soybean Jack genome.Due to the very lowtransformation efficiency,we did Agrobacterium rhizogenes-mediated genetic transformation,and identified the transgenic hairy roots of soybean Jack.The number of the transgenic hairy roots integrated GmPDR12-eGFP or eGFP were was decreased too when the concentration of aluminum chloride in the medium incresed,but the transgenic hairy roots integrated GmPDR12-eGFP grew significantly better than those hairy root integrated eGFP as control at the same concentration of aluminum chloride,about the Malondialdehyde(MDA),Compared with the control hairy root integrated eGFP the Malondialdehyde(MDA)content in hairy roots integrated GmPDR12-eGFP were much less.These results suggested that the GmPDR12 genes propably play an important role in Al-resisitance in soybean.In order to understand the effect of aluminum stress on the gene expression in the leaves of different genotype soybean and the mechanism of aluminum tolerance,we collected the leaves of aluminum-tolerant soybean BX10 and Al-sensitive soybean BD2 after aluminum stress,and extracted the total RNA from those samples.Through transcriptome sequencing and analysis,we identified 181 differentially expressed genes(DEGs),with most of genes up-regulated in Al-treatedleaves sample.Results discoved by Gene ontology and KEGG analysis indicated that some DEGs significantly enriced inenergy metabolism and lipid metabolisms of Al-tolerant soybean BX10,while other DEGs significantly enriced in carbon metabolism and amino acid metabolism of Al-sensitive soybean BD2.