Plant expression constructs comprising and uses thereof

Abstract

Methods of expressing a molecule of interest in a plant are disclosed. One method comprises contacting roots of the plant in a solution comprising at least one Geminivirus based expression construct so as to allow the at least one Geminivirus based expression construct to be absorbed by the roots, the expression construct comprising a polynucleotide encoding the molecule of interest, and further the expression construct being capable of systemic symptomless spread in a plant host, thereby expressing a molecule of interest in a plant. Expression constructs capable of systemic symptomless spread in a host plant are also disclosed.

Description

RELATED APPLICATIONS[0001]This application is a division of U.S. patent application Ser. No. 13 / 003,151 filed on Feb. 23, 2011, which is a National Phase of U.S. Patent Application No. PCT / IL2009 / 000682 having International filing date of Jul. 8, 2009, which claims the benefit of priority from U.S. Provisional Patent Application No. 61 / 129,596 filed on Jul. 8, 2008. The content of the above document is incorporated by reference as if fully set forth herein.SEQUENCE LISTING STATEMENT[0002]The ASCII file, entitled 59114SequenceListing.txt, created on May 1, 2014, comprising 61,103 bytes, submitted concurrently with the filing of this application is incorporated herein by reference.FIELD AND BACKGROUND OF THE INVENTION[0003]The present invention, in some embodiments thereof, relates to Gemini-virus constructs capable of symptomless, systemic spread in plant hosts.[0004]Plants may be genetically engineered for a variety of purposes including for the generation of plants with enhanced vi...

AI Technical Summary

Benefits of technology

The present invention provides an expression vector that can control the expression of various polynucleotides in plants, which can have beneficial effects. These effects include protecting plants from abiotic stress factors such as drought, heat, or chill, and conferring resistance to viruses, fungi, insects, nematodes, and diseases. The vector can also be used to express metabolic enzymes for use in the food-and-feed sector. The invention provides a valuable tool for researchers to study the functions of genes in plants and to develop new methods for improving crop protection.

Problems solved by technology

However, each of these delivery methods is not without limitations.

The direct DNA delivery systems such as particle bombardment, silicon carbide whisker technology and electroporation tend to result in integration of multiple copies of transgenes and are considered to be limited, unpredictable and transient.

Integration of foreign DNA into the plant genome to become a heritable trait raises many risks.

Traits beneficial to crops may, through horizontal gene transfer or hybridization through breeding with wild relatives, provide wild plants with unwanted competitive advantages.

Scientists now have the means to remove marker genes before a crop plant is developed for commercial use, but these means involve further costs and tedious procedures.

In addition, several species or varieties of plants are still difficult to transform.

However, viral vectors still hold many limitations.

Viral vectors are also limited in their systemic spread in the plant, in host ranges, expression stability, and in the size of insert which can be tolerated.

Finally, like transgenic plants, modified viruses are classified as a Genetically Modified Organism (GMO) and thus are subject to regulatory and moral constraints.

Movement and pathogenicity, however, require the activity of viral gene products.

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