Methods and means for altering fiber characteristics in fiber-producing plants

Abstract

Methods and means are provided for modulating fiber length in fiber producing plants such as cotton by altering the fiber elongation phase. The fiber elongation phase may be increased or decreased by interfering with callose deposition in plasmodesmata at the base of the fiber cells.

1 . A method for modifying a fiber of a fiber-producing plant comprising the step of altering a fiber cell elongation phase by modulating deposition of callose at the neck of the plasmodesmata at the base of said fiber cell.  
     
     
         2 . A method for increasing the length of a fiber of a fiber producing plant, comprising the step of introducing a chimeric gene into a cell of said fiber producing plant, wherein said chimeric gene, when expressed in said cell of said fiber-producing plant increases said deposition of callose and increases said fiber elongation phase.  
     
     
         3 . The method according to  claim 2 , wherein said chimeric gene comprises the following operably linked DNA elements: 
 a plant expressible promoter, preferably a plant expressible promoter which controls transcription preferentially in said fiber cells;    a transcribed DNA region, which when transcribed yields a double-stranded RNA molecule capable of reducing the expression of a gene endogenous to said fiber producing plant, said gene being involved in callose removal from said plasmodesmata, and said RNA molecule comprising a first and second RNA region wherein 
 said first RNA region comprises a nucleotide sequence of at least 19 consecutive nucleotides having at least about 94% sequence identity to the nucleotide sequence of said endogenous gene;  
 said second RNA region comprises a nucleotide sequence complementary to said 19 consecutive nucleotides of said first RNA region;  
 said first and second RNA region are capable of base-pairing to form a double stranded RNA molecule between at least said 19 consecutive nucleotides of said first and second region; and  
   a 3′ end region comprising transcription termination and polyadenylation signals functioning in cells of said plant.    
     
     
         4 . The method according to  claim 3 , wherein said promoter is a fiber-specific beta tubulin promoter from cotton, a fiber-specific actin promoter from cotton, a fiber specific promoter from a lipid transfer protein gene from cotton, a promoter from an expansin gene from cotton or a promoter from a chitinase gene in cotton.  
     
     
         5 . The method according to  claim 3 , wherein said endogenous gene is a 1,3-β-glucanase gene which is expressed at the base of said fiber cell, at the end of said fiber elongation phase in said fiber producing plant.  
     
     
         6 . The method according to  claim 5 , wherein said endogenous gene encodes a protein comprising the amino acid sequence of SEQ ID No 4 or wherein said gene comprises the nucleotide sequence of SEQ ID No 1.  
     
     
         7 . The method according to  claim 3 , wherein said first RNA region comprises a nucleotide sequence of at least 19 consecutive nucleotides having at least about 94% sequence identity to a nucleotide sequence encoding a protein comprising the amino acid sequence of SEQ ID No 4 or to the nucleotide sequence of SEQ ID No 1.  
     
     
         8 . The method according to  claim 2 , wherein said chimeric gene comprises 
 a plant-expressible promoter, preferably a plant-expressible promoter which controls transcription preferentially in said fiber cells;    a DNA region encoding a β-1,3 glucan synthase protein; and    a 3′ end region comprising transcription termination and polyadenylation signals functioning in cells of said plant.    
     
     
         9 . The method according to  claim 8 , wherein said DNA region encoding said β-1,3 glucan synthase protein, comprises the nucleotide sequence of SEQ ID No 2.  
     
     
         10 . The method according to  claim 8 , wherein said promoter is a fiber-specific beta tubulin promoter from cotton, a fiber-specific actin promoter from cotton, a fiber specific promoter from a lipid transfer protein gene from cotton, a promoter from an expansin gene from cotton or a promoter from a chitinase gene in cotton.  
     
     
         11 . The method according to  claim 2 , wherein said fiber producing plant is cotton.  
     
     
         12 . The method according to  claim 11 , wherein said fiber is a lint fiber.  
     
     
         13 . The method according to  claim 11 , wherein said fiber is a fuzz fiber.  
     
     
         14 . The method according to  claim 3 , further comprising introducing a second chimeric gene, wherein said second chimeric gene comprises the following operably linked DNA fragments: 
 a plant-expressible promoter, preferably a plant-expressible promoter which controls transcription preferentially in said fiber cells;    a DNA region encoding a β-1,3 glucan synthase protein; and    a 3′ end region comprising transcription termination and polyadenylation signals functioning in cells of said plant.    
     
     
         15 . The method according to any one of  claims 1  to  14   claim 1 , further comprising 
 growing plants obtained according to said method; and    isolating fibers from said fiber-producing plants.    
     
     
         16 . A method for decreasing the length of a fiber of a fiber producing plant, comprising the step of introducing a chimeric gene into a cell of said fiber producing plant, wherein said chimeric gene, when expressed in said cell of said fiber-producing plant decreases said fiber elongation phase and decreases said deposition of callose.  
     
     
         17 . The method according to  claim 16 , wherein said chimeric gene said chimeric gene comprises the following operably linked DNA fragments: 
 a plant-expressible promoter, preferably a plant-expressible promoter which controls transcription preferentially in said fiber cells;    a DNA region encoding a β-1,3 glucanase protein; and    a 3′ end region comprising transcription termination and polyadenylation signals functioning in cells of said plant.    
     
     
         18 . The method according to  claim 17 , wherein said DNA region encoding said β-1,3 glucanase protein comprises the nucleotide sequence of SEQ ID No 1.  
     
     
         19 . The method according to  claim 17 , wherein said promoter is a fiber-specific beta tubulin promoter from cotton, a fiber-specific actin promoter from cotton, a fiber specific promoter from a lipid transfer protein gene from cotton, a promoter from an expansin gene from cotton or a promoter from a chitinase gene in cotton.  
     
     
         20 . The method according to  claim 16 , wherein said chimeric gene comprises the following operably linked DNA elements: 
 a plant expressible promoter which controls transcription preferentially in said fiber cells;    a transcribed DNA region, which when transcribed yields a double-stranded RNA molecule capable of reducing the expression of a gene endogenous to said fiber producing plant, said gene being involved in callose deposition in said plasmodesmata, and said RNA molecule comprising a first and second RNA region wherein 
 said first RNA region comprises a nucleotide sequence of at least 19 consecutive nucleotides having at least about 94% sequence identity to the nucleotide sequence of said endogenous gene;  
 said second RNA region comprises a nucleotide sequence complementary to said 19 consecutive nucleotides of said first RNA region;  
 said first and second RNA region are capable of base-pairing to form a double stranded RNA molecule between at least said 19 consecutive nucleotides of said first and second region; and  
   a 3′ end region comprising transcription termination and polyadenylation signals functioning in cells of said plant.    
     
     
         21 . The method according to  claim 20 , wherein said promoter is a fiber-specific beta tubulin promoter from cotton, a fiber-specific actin promoter from cotton, a fiber specific promoter from a lipid transfer protein gene from cotton, a promoter from an expansin gene from cotton or a promoter from a chitinase gene in cotton.  
     
     
         22 . The method according to  claim 20  or  21 , wherein said endogenous gene is a 1,3-β-glucan synthase gene which is expressed in said fiber of said fiber producing plant.  
     
     
         23 . The method according to  claim 22 , wherein said endogenous gene encodes a protein comprising the amino acid sequence of SEQ ID No 3 or wherein said endogenous gene comprises the nucleotide sequence of SEQ ID No 2.  
     
     
         24 . The method according to  claim 21 , wherein said first RNA region comprises a nucleotide sequence of at least 19 consecutive nucleotides having at least about 94% sequence identity to a nucleotide sequence encoding a protein comprising the amino acid sequence of SEQ ID No 3 or to the nucleotide sequence of SEQ ID No 2.  
     
     
         25 . A method for identifying allelic variations of the genes encoding proteins involved in fiber elongation in a population of different genotypes, cultivars or varieties of a particular plant species, preferably a fiber-producing plant species, which are correlated either alone or in combination with the length of fibers produced, comprising the steps of 
 providing a population of different varieties or genotypes of a particular plant species or interbreeding plant species comprising different allelic forms of the nucleotide sequences encoding callose synthase or P-1,3 glucanase, particularly of SEQ ID No 1 or SEQ ID 2;    determining parameters related to fiber length for each individual of the population;    determining the presence of a particular allelic form of the nucleotide sequences encoding callose synthase or β-1,3 glucanase, particularly of SEQ ID No 1 or SEQ ID 2;    correlating the occurrence of particular fiber length with the presence of a particular allelic form of the mentioned nucleotide sequence or a particular combination of such allelic forms.    
     
     
         26 . A chimeric gene comprising the following operably linked DNA elements: 
 a plant expressible Promoter. Preferably a plant expressible promoter which controls transcription preferentially in said fiber cells:    a transcribed DNA region, which when transcribed yields a double-stranded RNA molecule capable of reducing the expression of a gene endogenous to said fiber Producing plant, said gene being involved in callose removal from said plasmodesmata, and said RNA molecule comprising a first and second RNA region wherein    said first RNA region comprises a nucleotide sequence of at least 19 consecutive nucleotides having at least about 94% sequence identity to the nucleotide sequence of said endogenous gene:    said second RNA region comprises a nucleotide sequence complementary to said 19 consecutive nucleotides of said first RNA region:    said first and second RNA region are capable of base-pairing to form a double stranded RNA molecule between at least said 19 consecutive nucleotides of said first and second region: and    a 3′ end region comprising transcription termination and polyadenylation signals functioning in cells of said plant.    
     
     
         27 . A cell of a fiber-producing plant comprising a chimeric gene according to  claim 26 .  
     
     
         28 . A fiber producing plant comprising a chimeric gene according to  claim 26 .  
     
     
         29 . A fiber producing plant according to  claim 28 , wherein fibers of said plant are increased in length compared to untransformed control plants.  
     
     
         30 . A fiber producing plant according to  claim 28 , which has increased drought resistance.  
     
     
         31 . A fiber producing plant according to  claim 28 , wherein said plant is cotton.  
     
     
         32 . Seed of a fiber producing plant, said seed comprising a chimeric gene according to  claim 26 .  
     
     
         33 . Fibers produced according to the method of  claim 1 .  
     
     
         34 . A method for increasing drought resistance in a fiber producing plant, said method comprising introducing a chimeric gene into cells of said fiber producing plant wherein said chimeric gene comprises the following operably linked DNA elements: 
 a plant expressible promoter which controls transcription preferentially in said fiber cells;    a transcribed DNA region, which when transcribed yields a double-stranded RNA molecule capable of reducing the expression of a gene endogenous to said fiber producing plant, said gene being involved in callose removal in said plasmodesmata, and said RNA molecule comprising a first and second RNA region wherein 
 said first RNA region comprises a nucleotide sequence of at least 19 consecutive nucleotides having at least about 94% sequence identity to the nucleotide sequence of said endogenous gene;  
 said second RNA region comprises a nucleotide sequence complementary to said 19 consecutive nucleotides of said first RNA region;  
 said first and second RNA region are capable of base-pairing to form a double stranded RNA molecule between at least said 19 consecutive nucleotides of said first and second region; and  
   a 3′ end region comprising transcription termination and polyadenylation signals functioning in cells of said plant.    
     
     
         35 . A method for increasing the length of a fiber in cotton, comprising introducing a the step of introducing a chimeric gene into a cell of said fiber producing plant, wherein said chimeric gene, when expressed in said cell of said fiber-producing plant increases said fiber elongation phase and increases said deposition of callose, said chimeric gene comprising 
 a plant expressible promoter;    a transcribed DNA region, which when transcribed yields a double-stranded RNA molecule capable of reducing the expression of a gene endogenous to said fiber producing plant, said gene being involved in callose removal from said plasmodesmata, and said RNA molecule comprising a first and second RNA region wherein 
 said first RNA region comprises a nucleotide sequence of at least 19 consecutive nucleotides having at least about 94% sequence identity to the nucleotide sequence of SEQ ID No 1;  
 said second RNA region comprises a nucleotide sequence complementary to said 19 consecutive nucleotides of said first RNA region;  
 said first and second RNA region are capable of base-pairing to form a double stranded RNA molecule between at least said 19 consecutive nucleotides of said first and second region; and  
   a 3′ end region comprising transcription termination and polyadenylation signals functioning in cells of said plant; or    said chimeric gene comprising the following operably linked DNA elements:    a plant-expressible promoter, preferably a plant-expressible promoter which controls transcription preferentially in said fiber cells;    a DNA region encoding a β-1,3 glucanase protein comprising the amino acid sequence of SEQ ID No 3 or the nucleotide sequence of SEQ ID No 2; and    a 3′ end region comprising transcription termination and polyadenylation signals functioning in cells of said plant.