Methods and compositions for the introduction and regulated expression of genes in plants

A method for introducing a polynucleotide of interest into a monocot leaf explant, said method comprising:

• a) providing a monocot leaf tissue explant;
• b) introducing into said monocot leaf explant:
• i) a heterologous polynucleotide encoding a babyboom cell proliferation factor and a heterologous polynucleotide encoding a Wuschel cell proliferation factor;
• and expressing said heterologous polynucleotide encoding said babyboom cell proliferation factor and said heterologous polynucleotide encoding said Wuschel cell proliferation factor;
• and
• ii) a polynucleotide of interest;
• and
• c) regenerating a monocot plant comprising the polynucleotide of interest.

A method for introducing a polynucleotide of interest into a monocot leaf tissue explant, said method comprising:

• a) excising a leaf segment from a leaf above the first leaf base node;
• b) dissecting said leaf segment into a leaf tissue explant;
• c) introducing into said leaf tissue explant:
• i) a heterologous polynucleotide encoding a babyboom cell proliferation factor and a heterologous polynucleotide encoding a Wuschel cell proliferation factor;
• and expressing said heterologous polynucleotide encoding said babyboom cell proliferation factor and said heterologous polynucleotide encoding said Wuschel cell proliferation factor;
• and
• ii) a polynucleotide of interest;
• and
• d) regenerating a monocot plant comprising the polynucleotide of interest.