title: Fast recovery of transgenic submergence tolerant rice cultivars of North-East India by early co-cultivation ofAgrobacteriumwith pre-cultured callus.
abstract: Agro-climatic conditions of North-East India are very complex and rice cultivars present in the region have been adapted to grow under harsh environmental conditions. Germplasm present in the region is considered to possess several important and unique traits that are of importance in rice improvement programs. Genetic engineering is a powerful tool to introduce new traits into crop plants. However, not much information is available on the methods to introduce foreign genes into North-East rice cultivars. Therefore, the main objective of this study is to develop transformation procedures for fast recovery of transgenic plants from North-East rice cultivars. To achieve this objective, a systematic study was carried out to identify media components and culture conditions for efficient embryogenic callus induction from the mature seeds and differentiation of callus into plantlets from two North-East deep water rice cultivars, Taothabi and Khongan. Also, role of preculture of callus onAgrobacterium-mediated transformation was studied. Co-cultivation ofAgrobacteriumwith 1-5 days precultured callus was found to result in high frequency of transformation. Detailed characterization of transgenic lines confirmed stable integration of transgenes and expression of reportergfpgene. The whole process starting from callus induction to regenerating of transgenic rice plants that can be established in the soil was achieved in about 35-45 days. The procedures developed were found to be applicable to a popular variety IR 64. Therefore, methods developed in this study should be useful not only to introduce new traits quickly but also to validate the function(s) of several candidate gene(s) identified under the functional genomics of rice.
authors.affiliation: Plant Transformation Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067 India.
authors.forename: Van Cuu
authors.initials: VC
authors.lastname: Nguyen
authors.affiliation: Plant Transformation Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067 India.|National Institute of Medicinal Materials (NIMM), Hanoi, Vietnam.
authors.forename: Van Khiem
authors.initials: VK
authors.lastname: Nguyen
authors.affiliation: Plant Physiology Lab., Department of Life Sciences, Manipur University, Imphal, Manipur 795003 India.
authors.forename: Chongtham Henary
authors.initials: CH
authors.lastname: Singh
authors.affiliation: Plant Physiology Lab., Department of Life Sciences, Manipur University, Imphal, Manipur 795003 India.
authors.forename: Guruaribam Shantibala
authors.initials: GS
authors.lastname: Devi
authors.affiliation: Plant Transformation Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067 India.
authors.forename: Vanga Siva
authors.initials: VS
authors.lastname: Reddy
authors.affiliation: Plant Transformation Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067 India.
authors.forename: Sadhu
authors.initials: S
authors.lastname: Leelavathi
keywords: Agrobacterium; North-East rice germplasm; Rice transformation; Submergence tolerance