Herbicide-tolerant soybean with high oleic acid content

The soybean is the result of a stacked event, created through the cross between TREUS™Plenish™ and Dicamba-tolerant (MON87708) soybean lines. The modified soy contains Glycine max acetohydroxy acid synthase for sulfonylurea herbicide tolerance, Stenotrophomonas maltophilia dicamba monooxygenase for tolerance to Dicamba (3,6-dichloro-2-methoxybenzoic acid) and a silencing construct to reduce the expression of endogenous ω-6 desaturase to reduce the production of polyunsaturated fatty acids.

PHP19340 and PHP17752; PV-GMHT4355

Genetic elements associated with PHP19340 and PHP17752:
Two linear DNA fragments were introduced to the parental soybean (Glycine max) line using microparticle bombardment:
-PHP19340A, a 2924 base pair fragment containing Glycine max microsomal omega-6-desaturase (FAD2-1) cassette; 
-PHP17752A, a 4512 base pair fragment containing the gm-hra (modified soybean acetohydroxy acid synthase (als) gene) cassette.

The fad2-1 cassette is under transcriptional control by the soybean Kunitz trypsin inhibitor gene (KTi3) and the KTi3 terminator. The fad2-1 fragment present in the cassette corresponds to a 40% of the middle portion of the endogenous gene. The cassette does not code for a protein.

The gm-hra cassette contains the coding sequence of als under transcriptional control of the soybean S-adenosyl-L-methionine synthetase (SAMS) constitutive promoter the endogenous als terminator. The coding sequence of gm-hra was produced by optimizing als.

Note:
Four insertions were present in the parental line:
- Insertion 1: one truncated PHP19340A fragment with a truncated KTi3 terminator and intact fad2-1 fragment and intact KTi3 promoter, one intact PHP19340A fragment, one intact PHP17752A fragment, one truncated PHP19340A fragment with an intact KTi3 promoter and a truncated fad2-1 fragment, and one truncated PHP19340A fragment with a truncated KTi3 promoter and truncated fad2-1 fragment.
- Insertion 2: one truncated PHP19340A fragment with a truncated KTi3 promoter and with intact fad2-1 fragment and intact KTi3 terminator.
- Insertion 3: one truncated copy of the KTi3 promoter with a non-functional 495 bp fragment of the plasmid backbone; and
- Insertion 4: two truncated PHP19340A fragments in an inverted repeat configuration, both with a truncated KTi3 promoter and intact fad2-1 fragment and KTi3 terminator.

Genetic elements associated with PV-GMHT4355:
In the parental line (MON87708), an expression cassette for Stenotrophomonas maltophili Dicamba monooxygenase (dmo) was integrated into the genome. Expression of the dmo is under control of the constitutive Peanut chlorotic streak caulimovirus promoter and the Pisum sativum Rubisco small subunit 2 (RbcS2 or E9) terminator. The 5' untranslated region from Tobacco Etch Virus was included to enhance translation, as well as the P. sativum RbcS2 chloroplast transit peptide to localize the DMO protein to the chloroplast.

Note:
- Southern blot analysis indicated that a single copy of the dmo cassette was present in the parental line.
- A second T-DNA with a 5-enolpyruvylshikimate-3-phosphate synthase was bred out of the parental line and thus is not expected to be present in this stacked event.

For more information, please refer to the parental LMO records.

Under the control of a seed-preferred KTi3 promoter, transcription of the omega-6 desaturase fragment acts to silence the expression of the endogenous soybean omega-6 desaturase via RNA interference. The reduction in expression of the endogenous gene impedes biosynthesis of polyunsaturated fatty acids. Thus, the fatty acid composition in the soybean seeds is changed (increased proportion of oleic acid and decreased proportions of linoleic and linolenic acids).