The present invention relates to plants with increased levels of water soluble carbohydrates, particularly fructan, in the stem and leaf sheath. The present invention also provides methods of identifying and/or producing these plants. In particular, the present invention relates to a novel class of polypeptides designated MYB13 which upregulate the expression of enzymes involved in fructan synthesis. The present invention further relates to a novel promoter element that can be used to express genes predominantly in the stem and leaf sheath during the early reproductive stage of a plant.

The present invention provides a method for increasing the sucrose ester content of a tobacco plant or tobacco cell culture, the method comprising modifying said tobacco plant or tobacco cell culture by inhibiting the activity or expression of a diterpene synthesis gene. The present invention also provides for the use of a diterpene synthesis gene for increasing the sucrose ester content of a tobacco plant or tobacco cell culture, as well as tobacco cells, tobacco plants, tobacco plant propagation materials, harvested leaves, processed tobaccos, or tobacco products obtainable in accordance with the invention.

Methods and means are provided to produce positively charged oligosaccharides in the plant cell wall by introducing into said plant cell a Nodulation C protein fused to a heterologous Golgi signal anchor sequence.

The invention provides combining certain genetic mutations in plants to increase sugar levels in the vegetative tissues of the plants. The specific combinations of mutations yield increased oil production in the vegetative tissues. In one embodiment, a plant comprises two mutations, wherein the two mutations are an adg1 mutation and a suc2 mutation. In one embodiment, a plant comprises three mutations, wherein the three mutations are an adg1 mutation, a suc2 mutation and a sdp1 mutation, or comprises an adg1 mutation, a suc2 mutation and a tt4 mutation. In one embodiment, the plant comprises four mutations, wherein the four mutations are an adg1 mutation, a suc2 mutation, an sdp1 mutation, and a tgd1 mutation, or comprises an adg1 mutation, a suc2 mutation, a tt4 mutation and a tgd1 mutation.

The present invention relates to a mutant, non-naturally occurring or transgenic plant cell comprising: (i) at least one polynucleotide comprising, consisting or consisting essentially of a sequence encoding an isopropylmalate synthase and having at least 60% sequence identity to SEQ ID NO:1 or SEQ ID NO:10 or SEQ ID NO: 12 or SEQ ID NO:14; or (ii) a polypeptide encoded by said polynucleotide(s); or (iii) a polypeptide having at least 60% sequence identity to SEQ ID NO:2 or SEQ ID NO:11 or SEQ ID NO:13 or SEQ ID NO:15; or (iv) a construct, vector or expression vector comprising said polynucleotide sequence(s), optionally wherein said construct, vector or expression vector additionally comprises a promoter comprising, consisting or consisting essentially of the sequence set forth in SEQ ID NO:8 or a variant thereof with at least about 60% identity thereto or a trichome promoter.

Provided are isolated polynucleotides encoding a polypeptide at least 80% homologous to the amino acid sequence selected from the group consisting of SEQ ID NOs: 757, 456-756, 758-774, 8385-10836, and 10838-14462; and isolated polynucleotide comprising nucleic acid sequences at least 80% identical to SEQ ID NO: 377, 1-376, 378-455, and 775-8384. Also provided are nucleic acid constructs comprising same, isolated polypeptides encoded thereby, transgenic cells and transgenic plants comprising same and methods of using same for increasing yield, biomass, growth rate, vigor, oil content, fiber yield, fiber quality, abiotic stress tolerance, and/or nitrogen use efficiency of a plant.

The present invention relates to a plant having an improved sugar content in fruit compared with its wild type plant, which has a mutant cyclin F-box gene comprising a nucleotide mutation that causes a non-conservative amino acid substitution in the cyclin F-box protein. The present invention also relates to a parthenocarpic plant having a mutant cyclin F-box gene comprising a nucleotide mutation that causes a non-conservative amino acid substitution in the cyclin F-box protein.

A novel class of transporter protein, referred to as SWEET, GLUE or Gl, is disclosed. These transporters provide a novel system for the transportation of sugars across membranes within a cell and between the inside and outside of a cell. Such transporters are useful for understanding and altering the sugar concentration within certain organs of an organism, and within certain organelles within the cell. These transporters are also useful in protecting plants from a pathogen attack.

An isolated nucleic acid molecule is provided comprising a nucleotide sequence which encodes a glutamine:fructose-6-phosphate amidotransferase from E. coli which is particularly suitable for expression in cotton plant cells. The invention also relates to plant cells or plants, in particular to cotton plant cells or cotton plants which produce an increased amount of positively charged polysaccharides in their cell walls. Furthermore, methods and means are provided to increase the content of positively charged polysaccharides in the cell walls of cotton cells, in particular in cotton fibers. Fibers obtained from such cotton plants have an altered chemical reactivity which can be used to attach reactive dyes or other textile finish reagents to these fibers.

The invention provides compositions and methods for inhibiting the expression of the gene XAX1 in grass plants. Plants with inhibited expression of XAX1 have use, e.g., in biofuel production by increasing the amount of soluble sugar that can be extracted from the plant.