Expression of the cry1EC gene in castor (Ricinus communis L.) confers field resistance to tobacco caterpillar (Spodoptera litura Fabr) and castor semilooper (Achoea janata L.)

Abstract

Castor (cv. DCS-9) has been transformed through Agrobacterium-mediated and particle gun bombardment methods using appropriate vectors containing the Bt chimeric gene cry1EC driven by enhanced 35S promoter. About 81 and 12 putative transformants were regenerated following selection on hygromycin and kanamycin, respectively. Southern analysis of DNA extracted from T(0) plants confirmed integration of the introduced gene in castor genome. The integration and inheritance of the introduced genes was demonstrated up to T(4) generation by PCR and Southern analysis. Southern analysis of two events having single and two copies showed the same pattern of integration in the subsequent generations. Insect feeding experiments conducted in the laboratory by releasing neonate larvae of castor semilooper and S. litura on leaf tissues excised from transgenic and control plants showed varying degrees of larval mortality and slow growth in larvae fed on transgenic leaf tissue. Field bioassays against Spodoptera litura and castor semilooper conducted for eight events in T(1)-T(4) generations under net confinement were more informative and events conferring resistance to the two major defoliators were identified.

Direct in vitro regeneration of castor bean plants (Ricinus communis) using epicotyls

“…Once the regeneration of the adventitious shoots is achieved, an efficient mechanism for rooting them should be established to guarantee successful micropropagation and subsequent survival of these explants in the acclimatization phase. This study showed that 93.3% of plants (AHN et al, 2007), have been used for the in vitro rooting of castor bean plants, it has been evidenced that NAA is ideal for the rooting of adventitious shoots in these plants (SUJATHA et al, 2009;ALAM et al, 2010;KANSARA et al, 2013;).…”

“…Establishing the optimal culture medium for the in vitro growth of any plant is challenging; castor bean is no exception. Generally, Murashige and Skoog (MS) basal medium in different concentrations has been successfully used for the growth of all the stages of castor bean plant (SUJATHA; REDDY, 1998;SUJATHA, M;MAKKAR, H;BECKER, K, 2005;AHN et al, 2007;AHN, CHEN, 2008). However, various difficulties have been reported in the culturing of different cultivation stages, such as low seed germination which does not exceed 50% (MEDEROS MOLINA; SCHOBERT, 1995).…”

Role of conventional and biotechnological approaches in genetic improvement of castor (Ricinus communis L.)

“…For production of animal feed and rations, ricin-free castor meal will certainly play an important and significant role. Sujatha et al (2009) reported the use of Agrobacterium-mediated and biolistic bombardment methods for expression of the cry1EC gene in castor to confer field resistance to tobacco caterpillar and castor semilooper (Sujatha et al, 2009). Recently, a report on development of transgenic lines developed from two-day-old seedlings infected with Agrobacterium, EHA105/pBinBt8 harboring cry1AcF indicated strong resistance against Spodoptera litura in greenhouse based bioassay.…”

Genetic Improvement of Oilseed Crops Using Modern Biotechnology

“…In the same way, toward obtaining biotechnological strategies for the control of castor semilooper, [76] reported the use of Agrobacterium-mediated and biolistic bombardment methods for expression of the cry1EC gene in castor bean. Trying to face Spodoptera litura, [77] recently reported on the development of an A. tumefaciens mediated in planta transformation protocol for castor bean.…”