Indica Rice Cultivar IRGA 424, Transformed With <I>cry</I> Genes of <I>B. thuringiensis</I>, Provided High Resistance Against <I>Spodoptera frugiperda</I> (Lepidoptera: Noctuidae)

Abstract

Plant expression of the entomopathogenic bacteria Bacillus thuringiensis cry gene has reduced the damage created by insect pests in several economically important cultures. For this study, we have conducted genetic transformation of the indica rice "IRGA 424", via Agrobacterium tumefaciens, using the B. thuringiensis cry1Aa and cry1B genes, with the objective of obtaining rice plants resistant to the insect pests from this culture. The gene constructions harbor the promoters maize proteinase inhibitor and ubiquitin. The results showed that high concentration of the hormone 2,4-dichlorophenoxyacetic acid and agarose as the gelling agent helped the production of embryogenic calli for the analyzed cultivar. More than 80% of the obtained transformed plants revealed the integration, using polymerase chain reaction, of the cry1Aa and cry1B genes. Analysis of the expression of the heterologous protein by Western blotting revealed the expression of the Cry1B delta-endotoxin in IRGA 424 plants transformed with the ubiquitin promoter. Data showed the production and dissemination of a high number of embryogenic calli in addition to obtaining plants transformed with the cry1Aa and cry1B genes until the reproductive phase. The feed bioassays with the transformed plants and Spodoptera frugiperda (JE Smith) larvae indicated high rates of mortality to the insect target. The highest corrected mortality rate achieved under laboratory conditions with Bt-rice plants transformed with the cry1B and cry1Aa genes was 94 and 84%, respectively. Thus, our results demonstrated the great potential of transformed Bt-rice plants in controlling the damage caused by these insect pests in rice paddy fields.

Engineering the bacterial endophyte Burkholderia pyrrocinia JK-SH007 for the control of lepidoptera larvae by introducing the cry218 genes of Bacillus thuringiensis

“…Then the cultures were kept at 42 C in a shaking incubator with vigorous shaking. Cells were harvested at different time points (4,8,12,16,20 and 24 h) for protein quantitation.…”

“…The toxicity was tenfold compared to that of the strain BT-OP [3]. In 2013, Pinto et al [4] cloned and transformed cry1Aa and cry1B genes from B. thuringiensis into Indica rice cultivar IRGA 424 via Agrobacterium tumefaciens. The bioassays with the transformed plants and Spodoptera frugiperda (JE Smith) larvae indicated high rates of mortality to the insect target, with a corrected mortality rate of 94% (cry1Aa) and 84% (cry1B), under laboratory conditions [4].…”

“…In 2013, Pinto et al [4] cloned and transformed cry1Aa and cry1B genes from B. thuringiensis into Indica rice cultivar IRGA 424 via Agrobacterium tumefaciens. The bioassays with the transformed plants and Spodoptera frugiperda (JE Smith) larvae indicated high rates of mortality to the insect target, with a corrected mortality rate of 94% (cry1Aa) and 84% (cry1B), under laboratory conditions [4]. In a recent study, Yilmaz et al [5] constructed a plasmid carrying the ICP gene Cry2Aa18 from B. thuringiensis (serotype israelensis), transferred it into the Escherichia coli BL21 (DE3) strain and successfully obtained a high yield of recombinant Cry2Aa18 (6.83 mg/mL).…”

Induction of shoot regeneration in cotyledon explants of the oilseed crop Sesamum indicum L.

“…Significant success has been achieved for plant regeneration through somatic embryogenesis using hypocotyl or cotyledon as explants [13], [16], [31]. Excepting in rice, somatic embryogenesis has hardly met with success in genetic engineering of crop plants as compared to indirect de novo shoot regeneration from explants [20]. The shoot tips and nodes are unsuitable for Agrobacterium mediated transformation as they give multiple shoots from pre-existing primordial shoot and/or shoot buds [24].…”

Biological aspects and predation behavior of Ceraeochrysa cubana against Spodoptera frugiperda

“…The main forms of control of S. frugiperda are associated to the use of resistant varieties, transgenic plants and, mainly, synthetic insecticides (Pinto et al, 2013;Souza et al, 2013). Frequent and indiscriminate use of insecticides to control S. frugiperda is one of the main obstacles to an environmentally sustainable production and generates concerns about the possibility of favoring the occurrence of insecticide-resistant populations (Farias et al, 2014).…”