Transcriptional repressors of cytokinin signaling and their use

摘要

The invention relates to fusion proteins capable of acting as transcriptional repressors of cytokinin signaling, to polynucleotides encoding these fusion proteins, to vectors and cells comprising these polynucleotides, and to transgenic plants and parts thereof comprising these polynucleotides, vectors, and cells.;The invention further relates to a process for making these transgenic plants and to the use of these transgenic plants for producing seeds of enhanced size, with enhanced seed filling, with reduced seed loss and/or with more rapid germination, and/or for producing a live root system with increased root mass, root length and/or root branching. The invention also relates to a method for enhancing the seed size, for enhancing seed filling, for reducing seed loss, and/or for reducing germination time and/or reproduction time, and/or for enhancing the root mass, root length and/or root branching of a plant and to seeds obtainable by the methods of the present invention.

主权项

1. A polynucleotide comprising a nucleic acid sequence encoding a fusion protein comprising;
(a) a DNA binding factor capable of specifically binding to a B-type Arabidopsis response regulator (ARR) DNA motif, the DNA motif comprising the sequence 5′-(A/G)GAT(T/C)-3′, wherein said DNA binding factor comprises a DNA binding domain of a B -type ARR, wherein said DNA binding domain is selected from the group consisting of:
(i) DNA binding domains of ARR1 according to SEQ ID NO: 1, ARR2 according to SEQ ID NO: 2, ARR10 according to SEQ ID NO: 3, ARR11 according to SEQ ID NO: 4, ARR12 according to SEQ ID NO: 5, ARR13 according to SEQ ID NO: 6, ARR14 according to SEQ ID NO: 7, and ARR18 according to SEQ ID NO:8 and(ii) a homologue of a DNA binding domain according to (i) from a plant other than Arabidopsis thaliana capable of specifically binding to a B-type ARR DNA motif, wherein said homologue exhibits at least 70% sequence identity to the DNA-binding domain of ARR1 of SEQ ID NO: 1 and when aligned to the DNA binding domain of ARR1 according to SEQ ID NO: 1, has the same amino acid as SEQ ID NO: 1 in the amino acid positions corresponding to positions 1, 3, 4, 41, 44, 45, 47, 48 and 49 of SEQ ID NO: 1 and (b) a transcriptional repressor domain, wherein said transcriptional repressor domain is an EAR motif.