Red and near infrared flourescent phyotochrome

1. An isolated nucleic acid encoding a phytochrome protein comprising a mutation in the P3 GAF domain, wherein said mutation is an amino acid substitution for tyrosine at the position corresponding to tyrosine 176 (Y176) in the reference cyanobacterial phytochrome 1 (Cph1) phytochrome from Synechocystis (SEQ ID NO:4), whereby the fluorescence emission of a bilin-protein adduct formed from said phytochrome protein is enhanced relative to the fluorescence emission of a bilin-protein adduct formed from the corresponding wild type phytochrome protein with the same bilin.

2. The nucleic acid of claim 1 , wherein said phytochrome protein, when combined with a bilin, produces a far red and/or NIR-emitting phytofluor.

3. The nucleic acid of claim 1 , wherein said nucleic acid encodes a phytochrome protein consisting of a single bilin-binding GAF domain, that when combined with a bilin produces a far red and/or NIR-emitting phytofluor.

4. The nucleic acid of claim 1 , wherein said substitution is a substitution of histidine for said tyrosine.

5. The nucleic acid according to any one of claims 1 through 4 , wherein said nucleic acid encodes a chimeric protein comprising a phytofluor tag.

6. The nucleic acid of claim 1 , wherein said nucleic acid comprises the nucleotide sequence depicted in FIG. 1A (SEQ ID NO:1).

7. The nucleic acid of claim 1 , wherein said nucleic acid consists of the nucleotide sequence depicted in FIG. 1A (SEQ ID NO:1).

8. The nucleic acid of claim 1 , wherein said phytochrome protein is a cyanobacterial phytochrome protein.

9. The nucleic acid of claim 1 , wherein said phytochrome protein is a plant phytochrome protein.

10. The nucleic acid of any one of claims 1 , 2 , 3 , 4 , 5 , 8 , and 9 , wherein said nucleic acid comprises a vector.

11. A cell or cell line that expresses an apoprotein encoded by a nucleic acid according to any of claims 1 - 5 , 6 , 7 , 8 , and 9 .