Transgenic sugarcane for the sustainable management of the sugarcane borer Diatraea saccharalis

Abstract

The sugarcane borer Diatraea saccharalis is a major pest of sugarcane (Saccharum spp. hybrids) in the Americas. The insect is partially controlled by cultural, biological, and chemical methods but still causes signifi-cant economic losses to sugarcane growers and processors. Currently, one of the most efficient strategies for pest control in other crops is the use of transgenic plants harbour-ing genes from Bacillus thuringiensis (Bt), which encode crystalline proteins (Cry and/or Vip) with insecticidal activ-ity, known as Bt genes/proteins. In sugarcane, the expression of individual Bt proteins has been previously reported, but not the stacking of two or more Bt proteins. In this study, Bt genes were incorporated by microprojectile bombardment into embryogenic sugarcane calli of the clones TUC 95-10 and TUC 03-12. The presence of the transgenes in 33 transgenic lines was verified by using PCR assays. Subsequently, transgenic lines were acclimated and multi-plied in the greenhouse to generate vegetative material for their phenotypic and molecular assessments. The expression levels of transcripts in candidate lines were quantified by real time quantitative PCR (qRT-PCR) assays. In conclu-sion, transgenic sugarcane lines with a higher level of expression of Bt transcripts compared with the control were developed. These promising lines will be used for future phenotypic tests to determine their resistance against D. saccharalis.