Methods for Increasing the Resistance of Plants to Hypoxic Conditions

A method for increasing the penetrance of roots of a plant into a growth medium, comprising the step of:

• a) providing a stress tolerance enhancing transgene to said plant cell or cells of said plant;
• wherein said stress tolerance enhancing transgene is
• i. a stress tolerance enhancing transgene capable of reducing the expression of plant endogenous PARP genes;
• ii. a stress tolerance enhancing transgene capable of reducing the expression of plant endogenous PARG genes;
• or
• iii. a stress tolerance enhancing transgene coding for a plant-functional enzyme of the nicotinamide adenine dinucleotide salvage synthesis pathway selected from nicotinamidase, nicotinate phosphoribosyltransferase, nicotinic acid mononucleotide adenyl transferase or nicotinamide adenine dinucleotide synthetase.

A method for increasing the tolerance of a plant cell or plant to hypoxic or anoxic conditions, comprising the step of:

• a) applying an effective amount of a compound of formula (I)
• wherein
• Het represents a heterocycle which is either mono- or polysubstituted by fluorine, chlorine, methyl or ethyl, wherein said heterocycle is
• pyrid-3-yl, pyrid-5-yl, 3-pyridinio, 1-oxido-5-pyridinio, 1-oxido-5-pyridinio, tetrahydrofuran-3-yl, or thiazol-5-yl,
• A represents C1-C6-alkyl, —N(R1)(R2) or S(R2),
• in which
• R1 represents hydrogen, C1-C6-alkyl, phenyl-C1-C4-alkyl, C3-C6-cycloalkyl, C2-C6-alkenyl or C2-C6-alkynyl, and
• R2 represents C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, —C(═O)—CH3 or benzyl,
• R represents hydrogen, C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, —C(═O)—CH3 or benzyl or together with R2 represents the groups below:
• —CH2—CH2—, —CH2—CH2—CH2—, —CH2—O—CH2—, —CH2—S—CH2—, —CH2—NH—CH2—, —CH2—N(CH3)—CH2—, and
• X represents N—NO2, N—CN or CH—NO2
• on said plant or on its locus, or on seeds of said plant.

A method for increasing the penetrance of roots of a plant into a growth medium, comprising the step of:

• a) applying an effective amount of a compound of formula (I)
• wherein
• Het represents a heterocycle which is either mono- or polysubstituted by fluorine, chlorine, methyl or ethyl, wherein said heterocycle is
• pyrid-3-yl, pyrid-5-yl, 3-pyridinio, 1-oxido-5-pyridinio, 1-oxido-5-pyridinio, tetrahydrofuran-3-yl, or thiazol-5-yl,
• A represents C1-C10-alkyl, —N(R1)(R2) or S(R2),
• in which
• R1 represents hydrogen, C1-C6-alkyl, phenyl-C1-C4-alkyl, C3-C6-cycloalkyl, C2-C6-alkenyl or C2-C6-alkynyl, and
• R2 represents C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, —C(═O)—CH3 or benzyl,
• R represents hydrogen, C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, —C(═O)—CH3 or benzyl or together with R2 represents the groups below:
• CH2—CH2—, —CH2—CH2—CH2—, —CH2—O—CH2, —CH2—S—CH2—, —CH2—NH—CH2—, or —CH2—N(CH3)—CH2—, and
• X represents N—NO2, N—CN or CH—NO2
• on said plant or on its locus, or on seeds of said plant.

A method for increasing the protrusion of the roots of a plant into a growth medium comprising

• a) transforming said plant with a foreign DNA comprising a stress tolerance enhancing transgene or a variant of an endogenous gene corresponding to such stress tolerance enhancing transgene, and/or
• b) applying an effective amount of 6-chloronicotinic acid or a compound of formula (I)
• wherein
• Het represents a heterocycle which is either mono- or polysubstituted by fluorine, chlorine, methyl or ethyl, wherein said heterocycle is
• pyrid-3-yl, pyrid-5-yl, 3-pyridinio, 1-oxido-5-pyridinio, 1-oxido-5-pyridinio, tetrahydrofuran-3-yl, or thiazol-5-yl,
• A represents C1-C6-alkyl, —N(R1)(R2) or S(R2),
• in which
• R1 represents hydrogen, C1-C6-alkyl, phenyl-C1-C4-alkyl, C3-C6-cycloalkyl, C2-C6-alkenyl or C2-C6-alkynyl, and
• R2 represents C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, —C(═O)—CH3 or benzyl,
• R represents hydrogen, C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, —C(—O)—CH3 or benzyl or together with R2 represents the groups below:
• —CH2—CH2—, —CH2—CH2—CH2—, —CH2—O—CH2—, —CH2—S—CH2—, —CH2—NH—CH2—, or —CH2—N(CH3)—CH2—, and
• X represents N—NO2, N—CN or CH—NO2.

A method for increasing the tolerance of a plant to hypoxic or anoxic conditions comprising

• a) transforming a plant with a foreign DNA comprising a stress tolerance enhancing transgene or a variant of an endogenous gene corresponding to such stress tolerance enhancing transgene, and/or
• b) applying an effective amount of 6-chloronicotinic acid or a compound of formula (I)
• wherein
• Het represents a heterocycle which is either mono- or polysubstituted by fluorine, chlorine, methyl or ethyl, wherein said heterocycle is
• pyrid-3-yl, pyrid-5-yl, 3-pyridinio, 1-oxido-5-pyridinio, 1-oxido-5-pyridinio, tetrahydrofuran-3-yl, or thiazol-5-yl,
• A represents C1-C6-alkyl, —N(R1)(R2) or S(R2),
• in which
• R1 represents hydrogen, C1-C6-alkyl, phenyl-C1-C4-alkyl, C3-C6-cycloalkyl, C2-C6-alkenyl or C2-C6-alkynyl, and
• R2 represents C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, —C(═O)—CH3 or benzyl,
• R represents hydrogen, C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkynyl, —C(═O)—CH3 or benzyl or together with R2 represents the groups below:
• —CH2—CH2—, —CH2—CH2—CH2—, —CH2—O—CH2—, —CH2—S—CH2—, —CH2—NH—CH2—, or —CH2—N(CH3)—CH2—, and
• X represents N—NO2, N—CN or CH—NO2.