Agronomic performance, chromosomal stability and resistance to velvetbean caterpillar of transgenic soybean expressing cry1Ac gene

Abstract

-The objective of this work was to analyze the agronomic performance and chromosomal stability of transgenic homozygous progenies of soybean [Glycine max (L.) Merrill.], and to confirm the resistance of these plants against Anticarsia gemmatalis. Eleven progenies expressing cry1Ac, hpt and gusA genes were evaluated for agronomic characteristics in relation to the nontransformed parent IAS 5 cultivar. Cytogenetical analysis was carried out on transgenic and nontransgenic plants. Two out of the 11 transgenic progenies were also evaluated, in vitro and in vivo, for resistance to A. gemmatalis. Two negative controls were used in resistance bioassays: a transgenic homozygous line, containing only the gusA reporter gene, and nontransgenic 'IAS 5' plants. The presence of cry1Ac transgene affected neither the development nor the yield of plants. Cytogenetical analysis showed that transgenic plants presented normal karyotype. In detached-leaf bioassay, cry1Ac plants exhibited complete efficacy against A. gemmatalis, whereas negative controls were significantly damaged. Whole-plant feeding assay confirmed a very high protection of cry1Ac against velvetbean caterpillar, while nontransgenic 'IAS 5' plants and homozygous gusA line exhibited 56.5 and 71.5% defoliation, respectively. The presence of cry1Ac transgene doesn't affect the majority of agronomic traits (including yield) of soybean and grants high protection against A. gemmatalis.Index terms: Anticarsia gemmatalis, Glycine max, plant resistance to insects, gene transfer.Performance agronômica, estabilidade cromossômica e resistência à lagarta-da-soja em soja transgênica que expressa o gene cry1AcResumo -O objetivo deste trabalho foi analisar a performance agronômica e a estabilidade cromossômica de progênies transgênicas homozigotas de soja [Glycine max (L.) Merrill.], e confirmar a resistência dessas plantas a Anticarsia gemmatalis. Onze progênies com expressão dos genes cry1Ac, hpt e gusA foram avaliadas quanto às características agronômicas, em relação à cultivar parental IAS 5 não transformada. Análises citogenéticas foram realizadas em plantas transgênicas e não transgênicas. Duas das 11 progênies transgênicas também foram avaliadas quanto à resistência a A. gemmatalis, em bioensaios in vitro e in vivo. Dois controles negativos foram utilizados nos bioensaios: uma linha transgênica homozigota, com apenas o gene repórter gusA, e plantas de 'IAS 5' não transgênicas. A presença do transgene cry1Ac não afetou nem o desenvolvimento nem a produtividade das plantas. As plantas transgênicas apresentaram cariótipo normal. No bioensaio com folhas destacadas, as plantas cry1Ac exibiram completa eficácia contra A. gemmatalis, enquanto os controles negativos foram significativamente danificados. Ensaios com plantas inteiras confirmaram a elevada proteção do cry1Ac contra a lagarta-da-soja, enquanto as plantas 'IAS 5' não transgênicas e a linha homozigota gusA exibiram 56.5 e 71.5% de desfolhação, respectivamente. A presença do transgene cry1Ac não afeta a performanc...

Assessment of the high‐dose concept and level of control provided by MON 87701 × MON 89788 soybean against Anticarsia gemmatalis and Pseudoplusia includens (Lepidoptera: Noctuidae) in Brazil

“…The cry1A ( tic107 ) soy showed full protection against A. gemmatalis, P. includens, C. aporema and H. zea in the field, with no apparent defoliation 8–10. Similarly, the transgenic strains of the IAS5 cultivar caused full A. gemmatalis mortality in both lab and greenhouse studies 6, 7. However, transgenic IAS5 cultivar strains were not assessed for the control of P. includens and other lepidopteran soybean pests.…”

“…In 1994 there was the first report of the successful introgression and expression of a native cry1Ab Bacillus thuringiensis Berliner ( Bt ) gene in soybeans 3. More recently, two independent efforts led to the development of experimental soybean lines expressing a Bt cry1Ac gene4–7 and lines expressing a synthetic cry1Ac ( tic107 ) gene 8–10. In the latter case, the lines contain event MON 87701 and express the TIC107 synthetic protein which is nearly identical to the native Cry1Ac protein 11.…”

Convergence of Bar and Cry1Ac Mutant Genes in Soybean Confers Synergistic Resistance to Herbicide and Lepidopteran Insects

“…Given that agronomic traits depend on the cry1Ac genes, responsive-related genes expression has been reported. The previous study evaluated that the majority yield was not affected by cry1Ac expression in transgenic soybean (Homrich et al, 2008 ) or found that there were no unintended changes in the seed composition of transgenic chickpea-expressed a truncated- cry1Ac gene (Gupta et al, 2020 ). In the present study, agronomic traits in the transgenic plants were similar to the non-transgenic plants ( Table 5 ).…”

Effect of azadirachtin on the control of Anticarsia gemmatalis and its impact on Trichogramma pretiosum

“…Velvetbean caterpillars, Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae), are a species with a large geographic distribution from Argentina to the USA (Homrich et al 2008). This insect causes damage to soybean crops; each caterpillar can consume up to 110 cm 2 of leaves in its larval stage and can cause complete plant destruction at high infestations (Walker et al 2000).…”