Luo Keming, Zheng Xuelian, Chen Yongqin, Xiao Yuehua, Zhao Degang, McAvoy Richard, Pei Yan, Li Yi
Biotechnology Research Center, Southwest University, Chongqing, 400716, P.R. China.
Plant Cell Rep. 2006 May;25(5):403-9. doi: 10.1007/s00299-005-0051-z. Epub 2005 Dec 21.
We have assessed the use of a homeobox gene knotted1 (kn1) from maize as a selectable marker gene for plant transformation. The kn1 gene under the control of cauliflower mosaic virus 35S promoter (35S::kn1) was introduced into Nicotiana tabacum cv. Xanthi via Agrobacterium-mediated transformation. Under nonselective conditions (without antibiotic selection) on a hormone-free medium (MS), a large number of transgenic calli and shoots were obtained from explants that were infected with Agrobacterium tumefaciens LBA4404 harboring the 35S::kn1 gene. On the other hand, no calli or shoots were produced from explants that were infected with an Agrobacterium strain harboring pBI121 (nptII selection) or from uninfected controls cultured under identical conditions. Relative to kanamycin selection conferred by nptII, the use of kn1 resulted in a 3-fold increase in transformation efficiency. The transgenic status of shoots obtained was confirmed by both histochemical detection of GUS activity and molecular analysis. The results presented here suggest that kn1 gene could be used as an effective alternative selection marker with a potential to enhance plant transformation efficiency in many plant species. With kn1 gene as a selection marker gene, no antibiotic-resistance or herbicide-resistance genes are needed so that potential risks associated with the use of these traditional selection marker genes can be eliminated.
我们评估了来自玉米的同源异型盒基因knotted1（kn1）作为植物转化选择标记基因的用途。受花椰菜花叶病毒35S启动子（35S::kn1）控制的kn1基因通过农杆菌介导的转化被导入烟草品种Xanthi中。在无激素培养基（MS）上的非选择性条件下（无抗生素选择），从感染携带35S::kn1基因的根癌农杆菌LBA4404的外植体中获得了大量转基因愈伤组织和芽。另一方面，感染携带pBI121（nptII选择）的农杆菌菌株的外植体或在相同条件下培养的未感染对照均未产生愈伤组织或芽。相对于nptII赋予的卡那霉素选择，使用kn1使转化效率提高了3倍。通过GUS活性的组织化学检测和分子分析证实了所获得芽的转基因状态。此处给出的结果表明，kn1基因可作为一种有效的替代选择标记，具有提高许多植物物种中植物转化效率的潜力。以kn1基因为选择标记基因，无需抗生素抗性或除草剂抗性基因，从而可以消除与使用这些传统选择标记基因相关的潜在风险。
