The maize (Zea mays) was produced through cross‑breeding of modified parental varieties SYN-BTØ11-1, SYN-IR162-4, DAS-Ø15Ø7-1, and MON-ØØ6Ø3-6.
Maize SYN-BTØ11-1 was modified for resistance to the Lepidoptera insect European corn borer (Ostrinia nubilalis) and tolerance to glufosinate-ammonium herbicides. To achieve resistance to the European corn borer, the maize expresses cry1Ab gene from Bacillus thuringiensis subsp. kurstaki, which have a pore forming mode-of-action in the epithelial lining of feeding larvae; cry1Ab produces a crystal delta-endotoxin that binds to specific midgut receptors in the insect larva, forming pores that disrupt osmotic balance and cause fatal cell lysis. To achieve resistance to glufosinate, the maize expresses the gene from Streptomyces viridochromogenes encoding phosphinothricin N-acetyltransferase encoding gene, which inactivates the active compound L-phosphinothricin through acetylation of the primary amino group.
Maize SYN-IR162-4 was modified for resistance against lepidopteran insect pests including fall armyworm (Spodoptera frugiperda), true armyworm (Pseudaletia unipuncta), beet armyworm (Spodoptera exigua), corn earworm (Helicoverpa zea), black cutworm (Agrotis ipsilon), western bean cutworm (Striacosta albicosta). The LM maize was also modified to express a selectable marker. To achieve resistance against lepidopteran insects, the maize expresses the vegetative insecticidal protein gene (vip3Aa20), a variant of the native vip3Aa gene isolated from Bacillus thuringiensis strain AB88, which is secreted during the vegetative growth phase of the bacterium; Vip3Aa20 is a vegetative insecticidal protein that binds to specific midgut receptors distinct from those recognized by Cry proteins, disrupts the integrity of epithelial cell membranes, and ultimately causes gut paralysis and death of the feeding larvae. For the selection marker, the maize expresses the manA gene from Escherichia coli, which encodes for phosphomannose isomerase.
Maize DAS-Ø15Ø7-1 was modified for resistance to the lepidopteran European corn borer (Ostrinia nubilalis) and tolerance to herbicide glufosinate ammonium. To achieve lepidopteran resistance, the modified corn Bacillus thuringiensis expresses the Cry1F protein (delta-endotoxin/crystal protein),which has a pore forming mode of action in the epithelial lines of the feeding insect larvae. To achieve tolerance to the herbicide glufinosinate, the modified corn expresses Streptomyces viridochromogenes phosphinothricin N-acetyltransferase, which acetylates the glufosinate ammonium herbicide to form a non-toxic compound, preventing the inhibition of glutamine synthetase and thus preserving ammonia levels and nitrogen metabolism in the plant.
Maize MON-ØØ6Ø3-6 was modified for tolerance to glyphosate herbicides. To achieve glyphosate tolerance, the maize expresses enzyme 5-enolpyruvylshikimate-3-phosphate synthase, encoded by the cp4 epsps gene from Agrobacterium tumefaciens strain CP4, which has reduced binding affinity for glyphosate and allows continued synthesis of aromatic amino acids through the shikimate pathway in the presence of the herbicide.