Impact of Insecticidal Cry Proteins on Soil Biota: A Metareview

Abstract

Genetic engineering offers the opportunity to develop plants with a variety of new traits that may be useful in pest control, provide resistance to extreme weather conditions as well as aid in bioremediation. One of the most popular genetically modified traits is Insect Resistance (IR). Larvicidal Cry protein producing genes of Bacillus thuringiensis are inserted in the plant body to make it resist the pest attack. But fate of these proteins in the plant biomass, soil and entire agroecosystem is highly contentious, as such genetic modification in plants requires detailed and deep understanding of the plant mechanisms. There is great complexity in this area of research as current understanding of the interactions of Bt crops with soil biota is lacking. This paper is in direction to assimilate and correlate the existing secondary data on the impact of Cry proteins on the soil biota. Aim is to bring together variegated research at the same table and analyse it through the impartial eye of a scientist to draw a honest and fair conclusion. Thus, a comprehensive analysis of published literature reporting the fate and effect of Cry protein on soil ecosystem was assessed. A meta review approach was adopted with three-dimensional study of effects of cry protein on soil microorganisms, soil dwelling invertebrates and other non-target organisms.  The review highlighted the contrasting and statistically insignificant findings in many studies. Further, it calls for rigorous chronic studies on complicated system of plant-microbe interface, to develop a better and improved understanding of ecological compatibility of Bt crops and their impacts on soil biota