Transgenic plants having altered lignin density

A method of modulating the density of lignin in a test plant compared to the corresponding wild-type plant cultured under the same conditions, the method comprising:

• introducing into said test plant or an ancestor thereof a polynucleotide construct comprising an RNAi nucleotide sequence;
• and thereafter,
• regenerating said plant,
• wherein said RNAi nucleotide comprises at least 20 consecutive bases with a sequence identity greater than 90% to SEQ ID NO:
• 1 and to SEQ ID NO:
• 3 wherein lignin density increases in said test plant or ancestor thereof.

A genetic construct, comprising:

• an RNAi sequence having 20 consecutive bases with a sequence identity greater than 90% to LATE ELONGATED HYPOCOTYL 1 (LHY1) and LATE ELONGATED HYPOCOTYL 2 (LHY2) genes, wherein said LHY1 gene comprises a nucleic acid sequence as set forth in SEQ ID NO:
• 1 or a sequence with greater than 90% sequence identity thereto and said LHY2 gene comprises a nucleic acid sequence as set forth in SEQ ID NO:
• 3 or a sequence with greater than 90% sequence identity thereto;
• and
• a heterologous promoter wherein said heterologous promoter is operantly linked to said sequence.

A genetic construct, comprising:

• an RNAi sequence having a sequence identity greater than 90% to at least 20 continuous bases from position 37 to 80 of LATE ELONGATED HYPOCOTYL 1 (LHY1), wherein said LHY1 sequence comprises a nucleic acid sequence as set forth in SEQ ID NO:
• 1 or a sequence with greater than 90% sequence identity thereto;
• and
• a heterologous promoter wherein said heterologous promoter is operantly joined to said sequence.