Green-tissue-specific, C4-PEPC-promoter-driven expression of Cry1Ab makes transgenic potato plants resistant to tuber moth (Phthorimaea operculella, Zeller)

Abstract

An important strategy for obtaining a safer transgenic plant may be the use of a spatial- or tissue-specific promoter, instead of a constitutive one. In this study, we have used a light-inducible maize PEPC promoter to regulate the cry1Ab gene, aiming to produce transgenic potatoes that are resistant to potato tuber moth (PTM) (Phthorimaea operculella, Zeller). Out of 60 regenerated lines having normal phenotypes, 55 lines were PCR-positive for both the cry1Ab and nptII genes. Southern analysis on three selected putative transgenic lines revealed that they have only a single intact copy of the cry1Ab gene. An investigation of the Cry1Ab protein in the leaves and light-exposed (LE) tubers of the transgenic lines demonstrated the presence of the protein in the foliage and green tubers but not in the light-not exposed (LNE) tubers. A bioassay analysis of excised leaves of nine randomly selected lines showed that eight lines had 100% PTM larval mortality. Confirming results were obtained in six selected lines using the whole plant bioassay in the greenhouse. LE transgenic tubers also exhibited 100% larval mortality; however, the levels of damage to the LNE transgenic tubers were high and statistically the same as those incurred by the non-transgenic ones. Based on the results, we believe that this spatial expression of Cry1Ab using the light-inducible PEPC promoter can control PTM infestation in the field and significantly reduce pollution transmission to storage potatoes.

Immune analysis of cry1Ab-genetically modified potato by in-silico analysis and animal model

“…However, the constitutive expression of transgenes using constitutive promoters-e.g., cauliflower mosaic virus (CaMV) 35S-is widely used in plant genetic engineering, but this may impose an extra metabolic burden and other metabolic effects on transgenic plants [17]. For this reason, we used a light inducible promoter (PEPC) for the Cry1Ab expression in transgenic potatoes [15]. The light-inducible PEPC promoter has specific advantages in plant genetic engineering for green tissue-consuming pests [15].…”

“…For this reason, we used a light inducible promoter (PEPC) for the Cry1Ab expression in transgenic potatoes [15]. The light-inducible PEPC promoter has specific advantages in plant genetic engineering for green tissue-consuming pests [15]. The application of the PEPC promoter would not only reduce the metabolic pressure imposed on transgenic potato plants, but also reduce concerns over the food safety of transgenic plants [17,18].…”

“…No-genetically modified (NGMP) (as control plant) and genetically modified potato (GMP) tubers producing Cry1Ab (as a pesticide) and NPTII (as selectable marker gene) proteins were grown in greenhouse conditions [15]. A light inducible phosphoenolpyruvate carboxylase (PEPC) promoter was induced the Cry1Ab expression, only under light conditions in transgenic potato plants.…”

Isolation and Characterization of a Green-Tissue Promoter from Common Wild Rice (Oryza rufipogon Griff.)

“…A transgenic potato resistant to potato tuber moths with 100% tuber moth larval mortality was developed by expressing cry1Ab under the control of the PEPC promoter, a green tissue-specific and light-inducible promoter from maize [ 39 ]. Cry9C driven by PNZIP promoter, a green tissue promoter from Pharbitis nil , was used to develop transgenic pest-resistant cotton, and the accumulation of cry9C protein in seeds was 100 times lower than that observed for the seeds of the CaMV 35S:Cry9C line [ 40 ]. In our study, we have isolated a novel rice green tissue-specific promoter that does not drive expression in endosperm, and the GUS activity in seeds was much lower than in green tissues.…”

Detection of genetically modified food in digesta and organs of rats fed transgenic potato

“…Transgenic potato plants harbouring cry1Ab gene for potato tuber moth (Phthorimaea operculella (Zeller)) resistance have been developed in the Agricultural Biotechnology Research Institute of Iran (Ghasimi Hagh et al, 2009). After field trials, the possible use of this transgenic potato as food and feed will be reported.…”