Transgenic plants including a transgene consisting of a hybrid nucleic acid sequence, comprising at least one unedited mitochondrial gene fragment from higher plants and process for producing them

Hybrid nucleic acid sequence, comprising at least the coding region of an unedited mitochondrial gene from higher plants, with which is associated a sequence capable of transferring the protein expressed by the said coding region to the mitochondrion, wherein:

• the coding regions of the unedited mitochondrial genes are selected from the group consisting of the genes encoding a protein of the ATP synthase complex which are selected from the group consisting of the wheat ATP9 gene fragment of Seq ID No:7 in unedited form and ligated to a mitochondrial transporter sequence, wherein the hybrid nucleic acid sequence comprising the ATP 9 gene, when transformed into a recipient plant, causes male sterility, and the wheat ATP6 gene in unedited form and ligated to a mitochondrial transporter sequence, wherein the hybrid nucleic acid sequence comprising the ATP 6A gene, when transformed into a recipient plant, causes male sterility, and
• the nucleic sequence capable of transferring the said expressed protein to the mitochondrion is selected from the group consisting of the fragments encoding yeast tryptophanyl tRNA synthetase, the β subunit of Nicotiana plumbaginifolia ATPase, the maize ATP/ADP translocator and a 303 base pair EcoRI/KpnI fragment comprising codons 1 to 62 of subunit IV of yeast cytochrome oxidase, which hybrid sequence is capable of modifying male fertility in plants having incorporated it.

Process for producing male sterile transgenic plants comprising transforming a selected higher plant into a male sterile transgenic plant by introducing into a recipient plant at least one copy of the hybrid nucleic acid sequence that is capable of modifying male fertility in plants having it incorporated therein, wherein said hybrid nucleic acid sequence comprises at least a coding region of an unedited mitochondrial gene from a higher plant, with which is associated a sequence capable of transferring the protein expressed by the said coding region to the mitochondrion, wherein:

• the coding region of the unedited mitochondrial gene is the wheat ATP6 gene in unedited form and ligated to a mitochondrial transporter sequence, wherein the hybrid nucleic acid sequence comprising the ATP 6 gene, when transformed into a recipient plant, causes male sterility;
• and wherein
• the nucleic acid sequence capable of transferring the said expressed protein to the mitochondrion is selected from the group consisting of:
• the fragments encoding yeast tryptophanyl tRNA synthetase, the beta sub-unit of Nicotiana plumbaginifolia ATPase,
• the maize ATP/ADP translocator, and a 303 base pair EcoRI/KpnI fragment comprising codons 1 to 62 of sub-unit IV of yeast cytochrome oxidase.

Process for inhibiting the production of pollen in selected higher plants, comprising the following steps:

• (a) inserting a hybrid nucleic acid sequence that is capable of modifying male fertility in plants having it incorporated therein, wherein said sequence comprises at least a coding region of an unedited mitochondrial gene from a higher plant, with which is associated a sequence capable of transferring the protein expressed by the said coding region to the mitochondrion, wherein:
• the coding region of the unedited mitochondrial gene is the wheat ATP6 gene in unedited form and ligated to a mitochondrial transporter sequence, wherein the hybrid nucleic acid sequence comprising the ATP 6 gene, when transformed into a recipient plant, causes male sterility;
• and wherein
• the nucleic acid sequence capable of transferring the said expressed protein to the mitochondrion is selected from the group consisting of:
• the fragments encoding yeast tryptophanyl tRNA synthetase, the β sub-unit of Nicotiana plumbaginifolia ATPase,
• the maize ATP/ADP translocator, and
• a 303 base pair EcoRI/KpnI fragment comprising codons 1 to 62 of sub-unit IV of yeast cytochrome oxidase
• into the selected plants to form a transgenic plant of decreased male fertility;
• (b) regenerating and culturing the transgenic plants obtained in (a);
• and
• (c) measuring the production and the viability of pollen from said transgenic plants.

Process for restoring male fertility to transgenic male-sterile plants, comprising the following steps:

• (1) transforming a selected higher plant by introducing at least one copy of a hybrid nucleic sequence that is capable of modifying male fertility in plants having it incorporated therein, wherein said sequence comprises at least a coding region of an unedited mitochondrial gene from a higher plant, with which is associated a sequence capable of transferring the protein expressed by the said coding region to the mitochondrion, wherein:
• the coding region of the unedited mitochondrial gene is the wheat ATP6 gene in unedited form and ligated to a mitochondrial transporter sequence, wherein the hybrid nucleic acid sequence comprising the ATP 6 gene, when transformed into a recipient plant, causes male sterility;
• and wherein
• the nucleic sequence capable of transferring the said expressed protein to the mitochondrion is selected from the group consisting of:
• the fragments encoding yeast tryptophanyl tRNA synthetase,
• the β sub-unit of Nicotiana plumbaginifolia ATPase,
• the maize ATP/ADP translocator, and
• a 303 base pair EcoRI/KpnI fragment comprising codons 1 to 62 of sub-unit IV of yeast cytochrome oxidase
• into a recipient plant, by means of a plasmid containing said sequence, whereby obtaining a transgenic male-sterile plant;
• (2) transforming the same higher plant as in (1), by introducing at least one copy of an antisense hybrid nucleic sequence comprising, in the reverse direction, at least the same coding region of the unedited plant mitochondrial gene as that contained in the said transgenic male-sterile plants obtained in (1), into a recipient plant, by means of a plasmid containing the said sequence, whereby obtaining transgenic male-fertile plants;
• and
• (3) crossing the transgenic male-sterile plants obtained in (1) and the male-fertile plants obtained in (2), in order to obtain hybrids.