Agrobacterium and biolistic transformation of onion using non-antibiotic selection marker phosphomannose isomerase.
A new selection system for onion transformation that does not require the use of antibiotics or herbicides was developed. The selection system used the Escherichia coli gene that encodes phosphomannose isomerase (pmi). Transgenic plants carrying the manA gene that codes for pmi can detoxify mannose-6-phosphate by conversion to fructose-6-phosphate, an intermediate of glycolysis, via the pmi activity. Six-week-old embryogenic callus initiated from seedling radicle was used for transformation. Transgenic plants were produced efficiently with transformation rates of 27 and 23% using Agrobacterium and biolistic system, respectively. Untransformed shoots were eliminated by a stepwise increase from 10 g l(-1) sucrose with 10 g l(-1) mannose in the first selection to only 10 g l(-1) mannose in the second selection. Integrative transformation was confirmed by PCR, RT-PCR and Southern hybridization.
Aswath
Chenna Reddy
CR
Indian Institute of Horticultural Research, Bangalore 560089, India. aswath@iihr.res.in
Mo
Sung Youn
SY
Kim
Doo Hwan
DH
Park
S Won
SW
D019470:Biolistics; D015870:Gene Expression; D005818:Genetic Engineering / Q000379:methods*; D005819:Genetic Markers / Q000235:genetics; D008358:Mannose / Q000378:metabolism; D008359:Mannose-6-Phosphate Isomerase / Q000235:genetics* / Q000378:metabolism*; D019697:Onions / Q000235:genetics*; D030821:Plants, Genetically Modified; D012231:Rhizobium / Q000235:genetics*; D036226:Seedlings; D014170:Transformation, Genetic; D044902:beta-Mannosidase / Q000235:genetics / Q000378:metabolism
D005819:Genetic Markers; D044902:beta-Mannosidase; D008359:Mannose-6-Phosphate Isomerase; D008358:Mannose