NOVELTY - An isolated nucleic acid molecule comprising a nucleotide sequence encoding a mutant cinnamyl alcohol dehydrogenase 2 protein, is new.    USE - The nucleic acid molecule is useful for producing transgenic maize plant having brown midrib phenotype, and at least one trait chosen from reduced lignin, increased digestibility, and ethanol yield which is useful for producing silage and biofuel. The plant is Zea mays. The method (M6) is useful for feeding silage-fed animal which is used for producing meat product. The silage-fed animal is a ruminant, preferably cow (all claimed).    ADVANTAGE - The silage is high nutritious and can be produced with high quality.    DETAILED DESCRIPTION - An isolated nucleic acid molecule comprising a nucleotide sequences exhibiting at least 80% homology to nucleotide sequences comprising 5924, 1512, 9360, 784, 160, and 114 base pair sequences (SEQ ID NOs: 1, 2, 23, 24, 62, and 63) fully defined in the specification, and nucleotide sequences encoding a mutant cinnamyl alcohol dehydrogenase 2 (CAD2) protein exhibiting at least 90% homology to an amino acid comprising a 147 amino acid sequence (SEQ ID NO: 3) fully defined in the specification or exhibiting at least 90% homology to amino acid comprising a 48 amino acid sequence (SEQ ID NO: 25) fully defined in the specification, is new. INDEPENDENT CLAIMS are included for the following:    (1) mutant CAD2 protein comprising amino acid sequence exhibiting at least 90% homology to amino acid sequences of SEQ ID NOs: 3 and 25;    (2) method (M1) for producing transgenic maize plant, involves introducing a premature stop codon into CAD2 gene in the maize plant;    (3) plant comprising the above-cited nucleic acid molecule;    (4) method (M2) for identifying a plant comprising mutant CAD2 gene, involves isolating nucleic acid molecules from a plant, contacting the nucleic acid molecules with an agent for identifying corn plants carrying a mutant CAD2 gene to produce a detectable signal that is an indicative of presence of mutant CAD2 gene in the plant, and screening the isolated nucleic acid molecules for 'ac' dinucleotide insertion at the location corresponding to nucleotide 3994 of wild-type CAD2 gene, where presence of 'ac' dinucleotide insertion is an indicative of mutant CAD2 gene, or a transposon insertion at location corresponding to nucleotide 2786 of the wild-type CAD2 gene, where presence of transposon insertion is an indicative of mutant CAD2 gene;    (5) plant identified by the above-cited method (M2);    (6) method (M3) for introducing brown midrib 1 (BM1) phenotype in maize, involves crossing a maize plant having BM1 phenotype with a maize plant lacking BM1 phenotype to produce F1 maize plants, identifying F1 maize plant using marker-assisted selection, propagating the identified F1 maize plant, and introducing the BM1 phenotype in maize;    (7) method (M4) for producing a genetically engineered organism, involves introducing the nucleic acid molecule into the organism;    (8) method (M4) for transferring maize mutant CAD2 gene, involves (a) analyzing genomic DNA of a first plant and second plant with probes that are specifically hybridizable to at least one marker linked to CAD2 gene, (b) sexually crossing the first and second plants to obtain a progeny population, (c) analyzing the progeny population for the presence of the at least one marker, (d) backcrossing an individual from the progeny population to the first or second plant to produce a next generation population that comprises the at least one marker linked to CAD2 gene, (e) determining whether member of the next generation population comprises a desired trait from the first or second plant and the CAD2 gene, and (f) repeating steps (d) and (e) until an individual is identified comprising the desired traits from the first or second plant and CAD2 gene, when the next generation population does not comprise desired trait from first or second plant and CAD2 gene;    (9) method (M5) for introducing maize mutant CAD2 gene into a host organism by genetic transformation, involves performing step (a) of the above-cited method (M4), introducing the isolated segment of genomic DNA into the host organism, and analyzing DNA of the host organism using probes;    (10) method (M6) for feeding a silage-fed animal, involves providing silage produced from the corn plant, and feeding the animal with the silage;    (11) meat product prepared from an animal fed;    (12) beef finishing ration comprising the corn silage;    (13) biofuel produced from the corn plant; and    (14) method (M7) for producing a genetically modified plant, involves providing a nucleic acid molecule comprising a wild-type CAD2 gene and the gene of interest, introducing the nucleic acid molecule into a BM1 plant, screening the plant or its progeny for normal pigmentation, and selecting a plant having normal pigmentation, where the plant comprises the gene of interest, or introducing the nucleic acid molecule into a plant homozygous for wild-type CAD2 allele, integrating the nucleic acid molecule into genome of the plant using zinc finger nuclease such that the CAD2 gene is inactivated, screening the plant or its progeny for a brown midrib phenotype, and selecting a plant having a brown midrib phenotype.