title: Agrobacterium-mediated high-frequency transformation of an elite commercial maize (Zea mays L.) inbred line.
abstract: An improved Agrobacterium -mediated transformation protocol is described for a recalcitrant commercial maize elite inbred with optimized media modifications and AGL1. These improvements can be applied to other commercial inbreds. This study describes a significantly improved Agrobacterium-mediated transformation protocol in a recalcitrant commercial maize elite inbred, PHR03, using optimal co-cultivation, resting and selection media. The use of green regenerative tissue medium components, high copper and 6-benzylaminopurine, in resting and selection media dramatically increased the transformation frequency. The use of glucose in resting medium further increased transformation frequency by improving the tissue induction rate, tissue survival and tissue proliferation from immature embryos. Consequently, an optimal combination of glucose, copper and cytokinin in the co-cultivation, resting and selection media resulted in significant improvement from 2.6 % up to tenfold at the T0 plant level using Agrobacterium strain LBA4404 in transformation of PHR03. Furthermore, we evaluated four different Agrobacterium strains, LBA4404, AGL1, EHA105, and GV3101 for transformation frequency and event quality. AGL1 had the highest transformation frequency with up to 57.1 % at the T0 plant level. However, AGL1 resulted in lower quality events (defined as single copy for transgenes without Agrobacterium T-DNA backbone) when compared to LBA4404 (30.1 vs 25.6 %). We propose that these improvements can be applied to other recalcitrant commercial maize inbreds.
authors: DuPont Agricultural Biotechnology, DuPont-Pioneer, 4010 Point Eden Way, Hayward, CA, 94545, USA, myeong-je.cho@pioneer.com.
authors: Myeong-Je
authors: MJ
authors: Cho
authors: Emily
authors: E
authors: Wu
authors: Jackie
authors: J
authors: Kwan
authors: Maryanne
authors: M
authors: Yu
authors: Jenny
authors: J
authors: Banh
authors: Wutt
authors: W
authors: Linn
authors: Ajith
authors: A
authors: Anand
authors: Zhi
authors: Z
authors: Li
authors: Susan
authors: S
authors: TeRonde
authors: James C
authors: JC
authors: Register
authors: Todd J
authors: TJ
authors: Jones
authors: Zuo-Yu
authors: ZY
authors: Zhao
mesh_terms: D060054:Agrobacterium / Q000235:genetics* / Q000502:physiology; D004269:DNA, Bacterial / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics / Q000382:microbiology; D014170:Transformation, Genetic / Q000235:genetics / Q000502:physiology*; D003313:Zea mays / Q000235:genetics* / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial; C036483:T-DNA