Truncated forms of atypical cys his rich thioredoxin 4 (acht4) capable of inhibiting acht4-mediated oxidation of the small subunit of adp-glucose pyrophosphorylase (aps1)

Abstract

The present invention provides compositions for attenuating the function of atypical CYS HIS rich thioredoxin 4 (ACHT4), a light-regulated protein expressed in plants and algae that controls starch storage in chloroplast, and methods for increasing plant and algae growth and yield.

What is claimed is: 
     
         1 . A recombinant polynucleotide encoding an atypical CYS HIS rich thioredoxin 4 (ACHT4) protein, wherein the C-terminal portion of said ACHT4 protein comprises an inactivating mutation. 
     
     
         2 . A composition comprising the polynucleotide of  claim 1 . 
     
     
         3 . An expression vector comprising the polynucleotide of  claim 1 . 
     
     
         4 . The expression vector of  claim 3  further comprising a constitutive, inducible, or tissue-specific promoter operably linked to the polynucleotide. 
     
     
         5 . A composition comprising the expression vector of  claim 4 . 
     
     
         6 . A cell comprising the expression vector of  claim 4 . 
     
     
         7 . A composition comprising the cell of  claim 6 . 
     
     
         8 . A seed comprising the recombinant polynucleotide of  claim 1 . 
     
     
         9 . A plant, or plant part, comprising the recombinant polynucleotide of  claim 1 . 
     
     
         10 . The plant or plant part of  claim 9 , wherein said plant is an  Arabidopsis  plant. 
     
     
         11 . The plant or plant part of  claim 9 , wherein said plant is a moss. 
     
     
         12 . A biofuel comprising the plant or plant part of  claim 9 . 
     
     
         13 . An alga comprising a C-terminal inactivated form of an atypical CYS HIS rich thioredoxin 4 (ACHT4) gene. 
     
     
         14 . A biofuel comprising the algae of  claim 13 . 
     
     
         15 . A polypeptide encoded by the recombinant polynucleotide of  claim 1 . 
     
     
         16 . A method of increasing the yield of a plant or algae comprising contacting a cell from said plant or algae with the recombinant polynucleotide of  claim 1 , thereby increasing the yield of said plant or algae. 
     
     
         17 . A method of increasing the productivity of a plant or algae comprising contacting a cell from said plant or algae with the recombinant polynucleotide of  claim 1 , thereby increasing the productivity of said plant or algae. 
     
     
         18 . A method of increasing the biomass of a plant or algae comprising contacting a cell from said plant or algae with the recombinant polynucleotide of  claim 1 , thereby increasing the biomass of said plant or algae. 
     
     
         19 . A method of stimulating the growth of a plant or algae comprising contacting a cell from said plant or algae with the recombinant polynucleotide of  claim 1 , thereby stimulating the growth of said plant or algae. 
     
     
         20 . A method of enhancing the starch content of a plant or algae comprising contacting a cell from said plant or algae with the recombinant polynucleotide of  claim 1 , thereby enhancing the starch content of said plant or algae.