Genes and methods for increasing disease resistance in plants
The present invention relates to the regulation of the natural defense system of plants through the introduction of foreign/native genes into plant cells, preferably into their genomes. More specifically, the methods relate to increasing citrus plant disease resistance by over-expressing genes involved in the innate plant defense system.
1. An isolated cDNA sequence encoding a polypeptide selected from the group consisting of the sequences set forth in SEQ ID NO: 14-26, wherein said cDNA is operably linked to a heterologous promoter.
2. A construct comprising a cDNA sequence selected from the group consisting of the sequences set forth in SEQ ID NO: 1-13, wherein said cDNA sequence encodes a polypeptide selected from the group consisting of the sequences set forth in SEQ ID NO: 14-26 and said cDNA is operably linked to a heterologous promoter.
3. The construct of claim 2 , wherein said heterologous promoter functions in plants and said heterologous promoter expresses a polypeptide sequence selected from the group consisting of the sequences set forth in SEQ ID NO: 14-26.
4. The construct of claim 3 , wherein the heterologous promoter is selected from the group consisting of a CaMV 35S promoter, polyubiquitin promoter, tissue specific promoter, and a tissue preferred promoter.
5. A plant cell comprising the construct of claim 2 .
6. A method for increasing resistance to citrus canker disease in a plant or cell, comprising overexpressing at least one cDNA sequence selected from the group consisting of the sequences set forth in SEQ ID NO: 1-13, wherein said cDNA sequence is operably linked to a heterologous promoter.
7. A method for increasing resistance to citrus canker disease in a plant or cell, comprising
(a) transforming a plant or cell with a construct comprising at least one cDNA sequence set selected from the group consisting of the sequences forth in SEQ ID NO: 1-13, operably linked to a heterologous promoter active in plant cells;
(b) regenerating a plant from said transformed plant or cell; and
(c) selecting a plant or cell that has increased resistance to citrus canker disease relative to a control plant.
8. The method of claim 7 , wherein the promoter is a constitutive promoter or a tissues specific promoter.
9. The method of claim 8 , wherein the tissue specific promoter is a xylem-specific promoter, phloem-specific promoter, or a xylem/phloem-specific promoter.
10. The method of claim 7 , wherein the promoter is operably linked to an enhancer.
11. The method of claim 7 , wherein the plant is a member of the Rutaceae family.
12. The method of claim 11 , wherein said plant is selected from the genera of Citrus, Poncirus, Fortunella, Murraya, Microcitrus, Limonia , and Eremocitrus.
13. A transgenic plant, plant cell, seed, or fruit produced by the method of claim 6 or 7 .
14. A transgenic plant having incorporated into its genome a cDNA sequence that encodes a disease resistance polypeptide selected from the group consisting of the sequences set forth in SEQ ID NO: 14-26.
15. The transgenic plant of claim 14 , wherein the polypeptide is encoded by a cDNA sequence selected from the group consisting of the sequences set forth in SEQ ID NO: 1-13.
16. A transgenic progeny, fruit, or seed of the plant of claim 15 , comprising said cDNA sequence.
17. A construct comprising a cDNA sequence selected from the group consisting of the sequences set forth in SEQ ID NO: 1-13, wherein said sequence is operatively linked to a heterologous promoter which functions in plants and said heterologous promoter expresses a polypeptide sequence selected from the group consisting of the sequences set forth in SEQ ID NO: 14-26.