Defensin-encoding nucleic acid molecules derived from nicotiana alata, uses therfor and transgenic plants comprising same
The present invention provides nucleic acid molecules derived from Nicotiana alata , which encode defensin-like molecules. The present invention contemplates the use of such nucleic acid molecules in the generation of transcienic plants having resistance or at least reduced sensitivity to plant pests including insects, microorganisms, fungi and/or viruses. The transcienic plants provided by the present invention include monocotyledonous and dicotyledonous plants, and particularly include crop plants and ornamental flowering plants.
1. An isolated nucleic acid molecule comprising a sequence of nucleotides encoding or complementary to a sequence encoding a polypeptide comprising the amino acid sequence as set forth in SEQ ID NO:8, wherein said polypeptide has activity against a plant pest, wherein said nucleic acid molecule further comprises a sequence of nucleotides encoding a C-terminal amino acid sequence and/or a sequence of nucleotides encoding an N-terminal signal sequence.
2. The isolated nucleic acid molecule of claim 1 , wherein said nucleic acid molecule further comprises a sequence of nucleotides encoding a C-terminal amino acid sequence and wherein the C-terminal amino acid sequence comprises the sequence as set forth in SEQ ID NO:12.
3. The isolated nucleic acid molecule of claim 1 or 2 , wherein said nucleic acid molecule further comprises a sequence of nucleotides encoding an N-terminal signal sequence and wherein the N-terminal signal sequence comprises the sequence as set forth in SEQ ID NO:10.
4. The isolated nucleic acid molecule of claim 1 , wherein the nucleotide sequence encodes the amino acid sequence set forth in SEQ ID NO:18.
5. The isolated nucleic acid molecule of claim 1 , comprising the nucleotide sequence as set forth in SEQ ID NO:7.
6. The isolated nucleic acid molecule of claim 2 , wherein the C-terminal amino acid sequence is encoded by the nucleotide sequence as set forth in SEQ ID NO:11.
7. The isolated nucleic acid molecule of claim 3 , wherein the N-terminal signal sequence is encoded by the nucleotide sequence as set forth in SEQ ID NO:9.
8. The isolated nucleic acid molecule of claim 4 , comprising the nucleotide sequence as set forth in SEQ ID NO:17.
9. A genetically modified plant cell, tissue, organ or whole plant which expresses the nucleic acid molecule of claim 1 .
10. The plant cell, tissue, organ or whole plant of claim 9 , wherein the plant is a cotton plant.
11. A progeny of the plant of claim 9 or 10 , wherein said progeny expresses the nucleic acid molecule.
12. A method for generating a plant with increased resistance to a plant pest, said method comprising introducing into a genome of a plant cell an expressible form of the nucleic acid molecule of claim 1 , 2 or 4 and regenerating a plant from said cell.
13. The method of claim 12 wherein the plant is a cotton plant.
14. The method of claim 12 wherein said nucleic acid is expressed in epidermal layers of petals and sepals, cortical cells of a style and/or the connective tissue of an anther.