Method for remodelling cell wall polysaccharide structures in plants

A method according to any of the preceding claims wherein the nucleotide sequence, which, following the introduction of the construct into a plant cell, results in an altered production of at least one target cell wall polysaccharide-modifying enzyme, is sufficiently different from endogenous genes of the host plant so that co-suppression will not occur.

A method according to any of the preceding claims in which an auxiliary enzyme is co-expressed with the target cell wall polysaccharide-modifying enzyme, wherein co-expression facilitates access of the polysaccharide-modifying enzyme to its substrate.

A method for modifying the biosynthesis in a plant cell of at least one complex cell wall polysaccharide to obtain a transgenic plant material that, relative to the wild type state, is modified in a complex cell wall polysaccharide structure, the modification being at least one of the overall glycosidic linkage pattern and the monosaccharide profile, the method comprising

• (i) providing a nucleic acid construct comprising a nucleotide sequence, the expression of which in a plant cell results in that at least one cell wall polysaccharide-modifying enzyme is targeted to a compartment in the plant cell where it is not normally present or in that the expression of a polypeptide naturally produced in the plant cell and affecting the biosynthesis of a cell wall polysaccharide is changed,
• (ii) transforming a plant cell with the nucleic acid construct, and
• (iii) deriving from said transformed plant cell a plant cell culture, a plant tissue or a transgenic plant in which the at least one cell wall polysaccharide-modifying enzyme, relative to the wild type plant, occurs in a different compartment.

A method according to 22 wherein the targeting sequence is a type II membrane anchored Golgi protein or a fragment thereof or a soluble Golgi targeted protein or a fragment thereof.

A method for providing a transgenic plant comprising parts in which at least one complex cell wall polysaccharide can be enzymatically processed after harvest by an enzyme present in the plant material itself, the method comprising

• (i) providing a nucleic acid construct comprising a nucleotide sequence, which, following the introduction of the construct into a plant cell, causes a cell wall polysaccharide-modifying enzyme to be expressed in a non-apoplastic or non-Golgi compartment or the expression of a cell wall polysaccharide-modifying enzyme in a form that is inactive under in vivo conditions but can be activated after harvest of plant material derived from the plant cell,
• (ii) transforming a plant cell with the nucleic acid construct, and
• (iii) deriving from said transformed plant cell a transgenic plant material in which, under appropriate post harvest conditions, the at least one complex cell wall polysaccharide can be enzymatically processed after harvest by bringing the at least one complex cell wall polysaccharide into contact with the cell wall polysaccharide-modifying enzyme that is expressed in a non-apoplastic or non-Golgi compartment or by subjecting the harvested plant material to conditions under which the enzyme being expressed in an in vivo inactive form is activated.