Drought resistant plants and methods for making the same using transcriptional regulators

A genetically modified annual or perennial crop plant having increased tolerance to water deficit and/or salt stress as compared to a corresponding non-genetically modified wild type plant, wherein said plant has a reduced amount or activity of a Mediator subunit, and wherein the genome of said plant comprises a genetic modification selected from any one of:

• i) a non-silent mutation in an endogenous gene comprising a nucleic acid molecule encoding a Med18 polypeptide;
• ii) a transgene inserted into said genome, said transgene comprising a nucleic acid molecule encoding a ribonucleic acid sequence, which is able to form a double-stranded ribonucleic acid molecule, whereby a fragment of at least 17 nucleotides of said double-stranded ribonucleic acid molecule has a homology of at least 50% to a nucleic acid molecule encoding a Med18 polypeptide;
• iii) a mutation in an endogenous gene comprising a nucleic acid molecule encoding a Med18 polypeptide, induced by introducing into at least one plant cell a nucleic acid construct able to recombine with and silence, inactivate, or reduce the activity of the endogenous gene,
• wherein said Med18 polypeptide has an amino acid sequence having at least 80% amino acid sequence identity to a sequence selected from among SEQ ID NO's 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69 and 71.

A genetically modified plant having increased tolerance to water deficit and/or salt stress as compared to a corresponding non-genetically modified wild type plant, wherein said plant is a hardwood selected from among acacia, eucalyptus, hornbeam, beech, mahogany, walnut, oak, ash, willow, hickory, birch, chestnut, poplar, alder, maple, sycamore, ginkgo, a palm tree and sweet gum having a reduced amount or activity of a Med25 polypeptide, and wherein the genome of said plant comprises a genetic modification selected from any one of:

• i) a non-silent mutation in an endogenous gene comprising a nucleic acid molecule encoding a Med25 polypeptide;
• ii) a transgene inserted into said genome, said transgene comprising a nucleic acid molecule encoding a ribonucleic acid sequence, which is able to form a double-stranded ribonucleic acid molecule, whereby a fragment of at least 17 nucleotides of said double-stranded ribonucleic acid molecule has a homology of at least 50% to a nucleic acid molecule encoding a Med25 polypeptide;
• iii) a mutation in an endogenous gene comprising a nucleic acid molecule encoding a Med25 polypeptide, induced by introducing into at least one plant cell a nucleic acid construct able to recombine with and silence, inactivate, or reduce the activity of the endogenous gene,
• wherein said Med25 has an amino acid sequence having at least 80% amino acid sequence identity to a sequence selected from among SEQ ID NO's:
• 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, and 37.