Translocation of Insecticidal Bt Protein in Transgrafted Plants.

Area of Science:

• Agricultural Science
• Plant Biotechnology
• Food Safety

Background:

• Transgrafting involves combining genetically modified (GM) and non-GM plants.
• Edible parts of non-GM scions are typically considered non-GM food.
• Protein translocation across graft unions could affect non-GM food status.

Purpose of the Study:

• To investigate the translocation of insecticidal Bacillus thuringiensis (Bt) crystal proteins in transgrafted plants.
• To determine if Bt proteins move from GM rootstocks to non-GM scions.
• To assess the impact of Bt protein translocation on the non-GM food status of scion-derived products.

Main Methods:

• Utilized tobacco plants engineered to express the Cry1Ab gene (Bt protein).
• Performed transgrafting between GM rootstocks and non-GM scions.
• Analyzed scion foliar tissues and seeds for the presence of Cry1Ab protein.

Main Results:

• Trace levels of Cry1Ab protein were found in the engineered tobacco rootstock.
• Translocated Cry1Ab protein was detected in the foliar tissues of non-GM scions.
• Cry1Ab protein was not detected in the seeds derived from the non-GM scion.

Conclusions:

• Bt protein can translocate from GM rootstocks to scion foliar tissues.
• Translocation is limited, not reaching the seeds of the non-GM scion.
• Edible components from the non-GM scion can be commercialized as non-GM food products.