Transgenics in groundnut (Arachis hypogaea L.) expressing cry1AcF gene for resistance to Spodoptera litura (F.)

Abstract

Large number of primary transgenic events were generated in groundnut by an Agrobacterium mediated, in planta transformation method to assess the efficacy of cry1AcF against the Spodoptera litura. generation demonstrated homozygous nature. This clearly proved that though there is considerable improvement in average mean % larval mortality in T 2 generation, the cry1AcF gene was effective against S. litura only to some extent.

Progress in genetic engineering of peanut (Arachis hypogaea L.)—A review

“…Specificity of Bt toxins to certain groups of lepidopterous insects has restricted their usage as cry genes, but pyramiding of receptorspecific toxins in a single gene has always broadened the range of susceptibility. In this direction, improvement in the insecticidal property of a chimeric Bt gene with cry1Ac and cry1F domains resulting cry1AcF has been developed in peanut transformation for conferring resistance to S. litura (Keshavareddy et al, 2013). Plants exhibiting positive results by molecular analysis in insect bioassays using leaf tissue, under laboratory conditions, witnessed highest mean larval mortalities of 80.0% and 85.0% coupled with average mean larval mortality of 16.3% and 26.0% in the subsequent consecutive two generations.…”

“…To avoid interference of tissue culture-based regeneration, a nontissue culture-based in-planta transformation method has been attempted by Rohini and Rao (2000) using embryonic axes with one cotyledon excised from mature seeds, and Agrobacterium octopine strain (LBA4404) carrying reporter gene. Using similar protocol, tobacco chitinase (CHI), cry1X and cry1AcF genes were utilized for developing transgenic plants resistant to leaf spot, and S. litura either alone or in combination of H. armigera (Entoori et al, 2008;Keshavareddy et al, 2013;Rohini and Sankara, 2001). Abiotic stress tolerant peanut transgenic plants have also been developed using in-planta transformation protocol (Manjulatha et al, 2014).…”

Whisker-mediated transformation of peanut with chitinase gene enhances resistance to leaf spot disease

“…A higher whisker quantity and prolonged shaking can increase the transformation efficiency, whereas cell survival and regeneration are adversely affected. In other words, the whisker quantity, mixing speed and survival rate have to be well-balanced to optimize the efficiency (Frame et al 1994, Petolino et al 2000, Mizuno et al 2004, Keshavareddy et al 2013. Moreover, callus age affected the transformation efficiency greatly in different crops.…”

Synthetic cry1AcF Gene Imparts Resistance to Spodoptera litura (F.) and Amsacta albistriga Walker in Peanut (Arachis hypogaea L.) cv. VRI-2

“…The transgenic Pigeon pea plants expresiing synthetic cry1AcF showed resistance against Helicoverpa armigera with high larval mortality also showed resistance to Spodoptera litura in peanut and cotton (Ramu et al, 2012;Keshavareddy et al, 2013). Peanut transgenics with such novel hybrid construct therefore, would be ideal to tackle a range of caterpillar pests that attack them in the semi-arid tracts of South India.…”