Methods of improving drought tolerance and seed production in rice

Abstract

The invention provides for compositions and methods for producing plants that have higher yield in drought conditions by manipulating the G-proteins such as the rice alpha subunit gene, RGA1. In particular, the present invention provides for plants, varieties, lines, and hybrids, as well as plant tissues and plant seeds that contain modified G-protein activity, particularly RGA1 activity to engineer drought tolerance and improved seed production in plants, as well as improved tolerance to high density planting

What is claimed is: 
     
         1 . A genetically modified plant with improved seed production in drought conditions and/or improved survival at high planting densities compared to the seed production of a corresponding plant with no such modification; said modified plant having reduced G-protein activity when compared to a non-modified plant in the same conditions, said G-protein selected from the group consisting of:
 Gα, Gβ, Gγ, GPCR, and GCR1.   
     
     
         2 . The modified plant of  claim 1  wherein said G-protein protein activity is created by introducing an inhibition construct to said plant or an ancestor thereof. 
     
     
         3 . Seed of the plant of  claim 1 . 
     
     
         4 . The plant of  claim 1  wherein said plant is a maize, cotton, soybean, wheat, barley, rice, rye, oat or sorghum plant. 
     
     
         5 . The plant of  claim 1  wherein said plant is a rice plant. 
     
     
         6 . The plant of  claim 1  wherein said G-protein is a G-protein alpha subunit. 
     
     
         7 . The plant of  claim 1  wherein said modification is a loss of function modification. 
     
     
         8 . The plant of  claim 1  wherein said plant includes a heterologous construct that inhibits expression of a G-protein alpha subunit. 
     
     
         9 . The plant of  claim 1  wherein said plant includes a G-protein alpha subunit expression cassette that is an inhibitory cassette. 
     
     
         10 . The plant of  claim 1  wherein said G-protein alpha subunit sequence is SEQ ID NO: 1 or 5. 
     
     
         11 . An isolated nucleic acid molecule comprising a nucleotide sequence selected from the group consisting of:
 (a) the nucleotide sequence set forth in SEQ ID NO:1, or SEQ ID NO:3;   (b) a nucleotide sequence which encodes the amino acid sequence of SEQ ID NO:2 or 4;   (c) a nucleotide sequence which includes about 90% identity to the full length sequence of SEQ I NO:1 or 3.   
     
     
         12 . A nucleic acid construct comprising a nucleic acid molecule of  claim 11 , wherein the nucleic acid is operably linked to a promoter that drives transcription in a plant cell. 
     
     
         13 . A plant comprising in its genome at least one nucleic acid molecule of claim. 
     
     
         14 . Seed of the plant of  claim 13 . 
     
     
         15 . The nucleic acid construct of  claim 12  wherein said construct is an inhibition construct. 
     
     
         16 . A method for conferring or improving seed production under drought conditions and/or improved in a rice plant, said method comprising:
 (a) transforming said plant with a nucleic acid molecule comprising an inhibition construct with a heterologous sequence operably linked to a promoter that induces transcription of said heterologous sequence in a plant cell; and   (b) regenerating stably transformed plants, wherein said heterologous sequence comprises an inhibition nucleic acid molecule that reduces the activity or expression of one or more G-protein encoding sequences.   
     
     
         17 . The method of  claim 16  further comprising obtaining genetically modified progeny plants of one or more generations with increased growth in drought conditions. 
     
     
         18 . The method of  claim 16  wherein the inhibition construct is by co-suppression, antisense suppression, or RNAi-mediated suppression. 
     
     
         19 . The method of  claim 16  wherein the decrease is obtained by introduction of an inhibitory sequence. 
     
     
         20 . The method of  claim 17  wherein the progeny plants are obtained by selfing, crossing with another plant or clonal propagation.