November 2011

New Technology for More Efficient Breeding

As plant breeding continues to evolve and become more precise, Danziger Innovations Ltd. is taking it to even higher levels with technology that gives them unprecedented ability to improve and select for specific traits and characteristics.

MemoGene, a viral-based tissue culture independent technology for precise plant genomic modification, can be applied to all plants without using common genetic engineering. It is under a commercial agreement between Danziger Innovations Ltd. and Yissum, the technology transfer company of Hebrew University. MemoGene was developed through a joint venture between Israel’s Danziger “Dan” Flower Farm and Professor Alexander Vainstein’s laboratory at the Institute of Plant Sciences and Genetics in Agriculture of the Hebrew University of Jerusalem’s Robert H. Smith Faculty of Agriculture, Food and Environment.

“The MemoGene platform will revolutionize our ability to produce tailor-made varieties with new traits, increasing the value of agricultural and horticultural products, while also allowing for the deletion of negative and unwanted characteristics,” says Micha Danziger, CEO of Danziger
Innovations. “This platform can be applied to plants and cell cultures, to meet rapidly shifting trends in the areas of field and vegetable crops, horticulture, biofuels and phytomedicines, to name a few.”

The Technology

MemoGene is based on highly efficient viral vectors for DNA delivery, and on targeted endonucleases (enzymes) for nuclear and plastid genome manipulations. 

The novel MemoGene method uses a modified plant virus to transiently infect the plant tissues and cells with genes that encode a special enzyme (endonuclease) that is able to permanently change the plant genome in predetermined regions and in a specific manner. 

The unsuspecting plant cells manufacture these biological DNA editing scissors, which then act to cut and change the plant genome in virus-infected cells. Next, the virus is eliminated from the plant, and the seeds or vegetative tissues can be grown to generate fully modified plants.

So, how can it be used?

Applications

The MemoGene method bypasses current biotechnological barriers for precise genome editing and offers three main consumer applications in two validation phases.

Phase 1 – DNA Deletion: Viral-based targeted deletion of DNA is an extremely useful tool for the development and breeding of new plant varieties, especially in light of general genomic advances and due to its independence of complicated tissue culture procedures.

Due to the fact that it does not involve the insertion of a foreign gene to alter the expression of another gene, it should not be expected to be classified as regular genetic engineering. Therefore, it may not require the long and tedious approval of various regulatory authorities, which could translate to shorter time to market.

Within this first phase, the company offers two main applications:

1. Targeted “ID-ing”: Through deletion of readily identifiable segments of non-coding DNA (nuclear or plastid), a plant can be easily “tagged” for patentability. 

The company expects that the ability to “mark” plant varieties will be of enormous benefit to breeders by reducing their royalty and income losses along with legal processes and associated high costs.

2. Targeted Mutagenesis: Expression or suppression of specific plant traits will be achieved through deletion or alteration of gene (nuclear or plastid) activity, creating new commercially desirable “tailor-made” varieties.

Phase 2 – DNA Insertion/Substitution: The company’s R&D team has been developing the ability to perform targeted genetic modification by insertion and/or substitution. In the future, they will use the new viral-based method of genome correction to create new characteristics in plants. 

Through site-specific substitution or addition of consequential DNA sequences to nuclear and plastid genomes, they will be able to create new plants with improved traits.

For All Plants

Unlike current breeding methods, MemoGene is applicable to all plants, and provides a far more efficient, reliable alternative to traditional methods.

Cross breeding, for example, is effective but time consuming, expensive and restricted to a certain gene pool. Mutation breeding, or mutagenesis, is random and highly unpredictable. And genetic engineering is highly crop and variety specific.

In addition, each suffers other limitations, as they are work-intensive and usually are not suitable for tailor-made crops. 

“One of MemoGene’s important advantages is that this is a generic process that can be applied to many important crops with relatively reduced effort,” said Danziger.

MemoGene’s key advantages over the most common genetic engineering methods are:

• It is a highly efficient, site-specific method that does not leave traces in plant genomes, while allowing the insertion or deletion of DNA fragments.

• It is a generic process that requires small modifications for use in different plants (no need for a very specific protocol for each crop or variety), and is applicable even in recalcitrant plants that have proven to be resistant to genetic engineering using other methods. 

• There is no need for time-consuming tissue culture steps, since it may be applicable in planta.

• It offers the possibility of modifying traits controlled by DNA that is present in the nucleus and cell plastids (mitochondria and chloroplasts).

• It allows direct genetic modification of gametes (plant reproductive cells), which shortens the breeding process by eliminating the need to work with vegetative parts, grow and select them, then wait until the next generation is grown.

In addition, MemoGene allows simultaneous delivery of several genes to the same specific genome region as well as delivery of genes simultaneously to different cellular compartments. This added efficiency has direct impact on both the speed of breeding as well as the precision of the modifications and enhancements that can be made.

The MemoGene technology has already proven to be efficient in a wide variety of dicot and monocot crops, including peppers, cucumbers,
potatoes and tomatoes, as well as wheat, barley, maize, cotton and canola.

The Danziger Innovations team feels the possibilities could be nearly endless. As Danziger said simply, “It is a highly efficient method for breeding new varieties at reduced cost and time, with predictable results.”