[Maize transformation using xylose isomerase gene as a selection marker].
The xylA gene, encoding xylose isomerase, was cloned as a 1342-bp BamHI/SacI fragment from the E. coli. As a selection marker, the xylA gene was fused between the enhanced CaMV 35S promoter (E35S) and terminator (35St) in pBAC413 (Fig.2). pBAC413 was constructed to prevent the expression of sbeIIb in maize. PDS1000/He was used to bombard maize calli, which were induced to form by the elite inbred lines. The selection was carried out on the media containing concentrations of xylose from 0 to 100%. The results showed that the media containing 50% to 100% D-xylose were better, but differed with the genotype of maize (Tables 1 and 2). Successful integration of xylA gene into the maize genome was confirmed by DNA dot blotting, PCR and PCR-Southern hybridization (Figs.4 to 6). A method was established in which transformed maize cells were successively screened on a medium containing xylose instead of antibiotic and herbicide for bio-safety.
Guo
Xin-Mei
XM
Beijing Agro-Biotechnology Research Center, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, China.
Zhang
Xiao-Dong
XD
Liang
Rong-Qi
RQ
Zhang
Li-Quan
LQ
Chen
Yao-Feng
YF
D019747:Aldose-Ketose Isomerases / Q000235:genetics*; D015139:Blotting, Southern; D018745:Genome, Plant / Q000235:genetics; D015151:Immunoblotting; D008957:Models, Genetic; D016133:Polymerase Chain Reaction; D014170:Transformation, Genetic / Q000235:genetics; D003313:Zea mays / Q000235:genetics*
D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase