植物基因轉移

Abstract

近年來生物技術快速發展，已成為改良重要經濟作物的主要方法之一。生物技術開啟了一個契機，讓我們可能創造出任何適合特定農業上需要的植物。在1983年，首度有外來基因轉殖到植物且正常表現的報導。此劃時代的成果，開發了往後許多對植物基因分析及調節基因表現的研究；在實際應用上，基因轉移能獨特、有效地改造作物。目前已研發出許多的植物基因轉移方法，其中少數方法也已成功地應用於許多作物。植物基因轉移方法有：將分離的DNA直接轉移到植物原生質體、細胞或器官的直接基因轉移法，例如PEG (Polyethylene glycol)法、電穿孔(electroporation）、微量注射法（microinjection）、鉅量注射法（macroinjection）、花粉管途徑（pollen tube pathway）等方法；將DNA沾牯到金或鎢粒子，再利用粒子鎗（particle gun）打擊到植物組織的方法；以及利用土壤中的農桿菌（Agrobac-terium）之自然基因轉移特性的農桿菌法。本報導簡要的回顧到目前為止有關植物基因轉移的方法、策略及成果，並探討將來植物基因轉移研究的方向。集中在抗殺草劑、抗病蟲害、延緩後熟、改善營養成份、改變花色或植株形態及耐環境逆境之植物基因轉移等項目，加以探討。 Biotechnology has rapidly emerged as a practical means of improving economically important crops. Biotechnology opens up the possibility of creating modified plant forms tailored to meet specific agricultural needs. Expression of a foreign in transgenic plants was first reported in 1983, and this breakthrough has facilitated direct analysis of gene function and gene regulation mechanism. Moreover, in the applied arena, gene transfer has allowed the engineering of specific, useful modifications in transgenic crops. Of the many strategies devised for gene transfer, only a few have been successful in a wide range of plant species. Direct gene transfer, in which naked DNA is introduced into protoplasts or intact cells, may be achieved by polyethylene glycol (PEG), electroporation, microinjection, macroinjection or pollen tube pathway. Alternatively, plant tissue can be bombarded by DNA- coated particles using particle gun; Agrobacterium-mediated gene transfer exploits the natural gene transfer capacity of this soil bacterium. This report draws together the results so far reported on the emerging strategies and opportunities for crop improvement by gene transfer, to provide an overview and suggest the way forward for future work on plant gene transfer. Major focus is the recent success in engineering resistance to herbicide, insect pests, viruses, disease, delaying ripening, nutrient improvement, alternations of flower and growth patterns, and environmental stresses.