Nitrogen-Regulated Sugar Sensing Gene and Protein and Modulation Thereof

Abstract

The present invention relates to a nitrogen-regulated GATA transcription factor gene required for sugar sensing and the modulation of the expression of this gene to modulate a characteristic in a plant. The GATA transcription factor of the present invention is involved in regulating sugar sensing in plants and its expression is influenced by nitrogen status. Increased expression of this or substantially similar genes can produce plants with improved nitrogen utilization and increased yield.

Description

[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 11 / 331,199 filed Jan. 13, 2006 which claims priority from U.S. provisional patent application No. 60 / 643,575 filed Jan. 14, 2005, which are incorporated herein by reference in their entirety.FIELD OF THE INVENTION [0002] The present invention relates to methods of modulating agronomic traits in plants by modulating the expression of a GATA transcription factor in the plant cells. In particular the present invention relates to methods of improving nitrogen utilization in plants. The present invention also pertains to nucleic acid molecules isolated from Arabidopsis thaliana comprising nucleotide sequences that encode proteins that are sugar sensing and, ultimately, can modulate nitrogen uptake and overall carbon metabolism. BACKGROUND OF THE INVENTION [0003] Improvement of the agronomic characteristics of crop plants has been ongoing since the beginning of agriculture. Most of the land suitable for ...

AI Technical Summary

Benefits of technology

[0025] Accordingly, the present invention relates to a method of modulating a characteristic in a plant or plant cell comprising modulating expression of a GATA transcription factor gene in the plant or plant cell. In an embodiment of the invention, the expression of the GATA transcription factor gene is modulated by administering, to the cell, an effective amount of an agent that can modulate the expression levels of a GATA transcription factor gene in the plant cell. In a further embodiment of the invention, the agent enhances the expression levels of a GATA transcription factor gene in the plant cell.

[0027] In a particular embodiment, the present invention relates to a method of improving nitrogen utilization in a plant or plant cell comprising enhancing expression of a GATA transcription factor gene in the plant or plant cell. Improving nitrogen utilization in a plant will allow for reduce amounts of nitrogen fertilizer to applied to the plant with a concomitant reduction in costs to the farmer and cost to the environment since nitrate pollution is a major problem in many agricultural areas contributing significantly to the degradation of both fresh water and marine environments.

[0117] In one embodiment, the expression cassette is involved in a function such as, for example, but not limited to, carbon, nitrogen and / or sulfur metabolism, nitrogen utilization, nitrogen assimilation, photosynthesis, signal transduction, cell growth, reproduction, disease resistance, abiotic stress tolerance, nutritional composition, gene regulation, and / or differentiation. In a more specific embodiment, the chimeric polypeptide is involved in a function such as, nitrogen utilization, abiotic stress tolerance, enhanced yield, disease resistance and / or nutritional composition.

[0178] In a specific embodiment, hybridization of a polypeptide sequence encoded by a nucleotide sequence identical to or having substantial similarity to a nucleotide sequence listed in SEQ ID NO:1, SEQ ID NO:3 or SEQ ID NO:9, or an exon or domain thereof, or a sequence complementary thereto, or a polypeptide sequence encoded by a nucleotide sequence capable of hybridizing under medium stringency conditions to a nucleotide sequence listed SEQ ID NO:1, SEQ ID NO:3 or SEQ ID NO:9, or to a sequence complementary thereto, allows the sequence to form a duplex at medium or high stringency.

Problems solved by technology

However, the use of large amounts of nitrogen fertilizer has negative side-effects primarily around increasing cost of this input to the farmer and cost to the environment since nitrate pollution is a major problem in many agricultural areas contributing significantly to the degradation of both fresh water and marine environments.

These experiments have demonstrated that there is a genetic component to nitrogen use efficiency, but have not proved satisfactory in determining which genes are important for this process.

In addition, corn breeders have generally not targeted the maintenance of yield under limiting nitrogen fertilizer.

These types of field experiments on nitrogen use are difficult for a variety of reasons including a lack of uniformity of accessible nitrogen in a test field or between field sites under any treatment regime and the interplay of other environmental factors that make experiments difficult to interpret.

Therefore, although there is experimental evidence for genetic variation for this trait, it is difficult to make any conclusions from these experiments on what causes this variation.

However, most aspects of the regulation of these genes are still unclear and there is still no notion of how this regulation affects nitrogen use efficiency.

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