Construction Of CDNA Library On PDB～(leu)-vect1or Under Iron Deficiency Condition In Maize Roots;selection And Identification Related Genes

Lamda phage DNA was extracted from X zap eDNA library in iron梔eficient from maize roots. Lamda DNA was digested by Not I /xho I and ligated it into PDBL~ - vector which had been digested by Not I/SalT . Thus a new eDNA library including the shuttle plasmid from yeast to E.coli has been constructed . This library was transformaed to E.coli DH5o for preservation and to various yeast mutants including M3(ctrl),FTRUNB1( ~ ctr])and DDY4(fet3fet4) with LiAc method for selection. On the selection medium without copper and iron, with ferric citrate, eDNA clones which can restore the growth of these mutants were selected. These clones will be sequenced. The fdr3 cDNA was screened from an expression eDNA library in iron梔eficient from maize roots. It is a new gene. Fdr3 eDNA including a 1068bp ORF was 3. 3kb in length. The results supposed that the fdr3 Mrna was elevated under iron deficiency condition by Northern hybradization in maize and wheat roots. Song Xiufang subcloned it onto PDBL~ - vector , that was 2. 5kb in length. Its function was identified with yeast functional heterologous complementation. In her experiments, the expression of fdr3 could restore the growth of yeast mutant M3 on selective mediums. But no same result could appear in my experiments. The result by southern hybridization of non梚sotope tracing showed that fdr3 exsists in rice but has no polymorphism No fdr3 mRNA was expressed in rice roots by Northern blot . DNA stripe of 2. 5kb and 800bp in length were amplified in maize and wheat roots by PCR respectively. This is the basis of cloning fdr3 in wheat roots. The rice seedings were cultured under iron梔eficiency ,ferric citrate, Fecb and EDTA桭e respectively. Different root constructions were observed from three days ,five days, seven days and nine days-old roots. L.u...