Methods for increasing starch content in plants

摘要

Methods and compositions for increasing the starch content in green tissues of a plant are provided. The method comprises down-regulating the activity of starch degradation enzymes in a plant. The resulting transgenic plants of the invention have increased starch content in green tissues and exhibit a starch excess phenotype. In one embodiment the method involves manipulating a monocot plant to down-regulate the activity of a starch degradation enzyme. The plants are useful for improving the yield of free sugars from plant biomass and increase dried green tissue storage stability.

主权项

1. A method for increasing starch content in green tissues of a plant comprising:
a) inserting an expression cassette into a plant cell comprising a polynucleotide operably linked to a regulatory element that ensures transcription in plant cells, wherein expression of the polynucleotide inhibits or suppresses the expression of one or more endogenous starch degradation enzymes in green tissues selected from the group consisting of chloroplastic alpha amylase, glucan water dikinase, phosphoglucan water dikinase, limit dextrinase, isoamylase, chloroplastic beta-amylase, chloroplastic glucan phosphorylase, disproportionating enzyme, chloroplastic maltose transporter protein (Mex1), chloroplastic glucose transporter protein, and chloroplastic triose phosphate transporter protein, and wherein said regulatory element is a phosphoenol pyruvate carboxylase promoter and the plant cell is of a plant selected from the group consisting of maize, sugarcane, sorghum, millet, and switchgrass; b) regenerating transgenic plants from the plant cell of a); and c) producing said green tissue with increased starch content.