[Identification of the gene whose mutation leads to the appearance of recessive lethal germlings in Arabidopsis thaliana].

The data are presented on genetic and molecular-genetic analysis of a mutant from the collection of morphological insertion mutants of Arabidopsis thaliana we obtained earlier, which belongs to the phenotypic class of recessive lethal germlings. A nucleotide DNA sequence, 147 bp in size, was identified, which adheres to the left border area of T-DNA insertion. The site of localization of the insertion was determined using computer analysis.

[Identification of the gene whose mutation leads to hypocotyl tropism in Arabidopsis thaliana].

Genetic and molecular analysis of a mutant of Arabidopsis thaliana with bended hypocotyl from a previously obtained collection of insertion mutants is presented. The examined mutation was shown to be recessive and based on a single insertion of pLD3 vector T-region into the A. thaliana genome. Computer-aided analysis of a DNA region adjacent to the left border of the insertion revealed a putative site of T-DNA insertion, the At1g15760 gene from 609-bp chromosome 1 represented by a single exon.

[Identification of the gene whose mutation leads to the morphological changes in the hypocotyl of Arabidopsis thaliana].

The results of genetic and molecular genetic analysis of line 176 of Arabidopsis thaliana with reduced hypocotyls obtained from a previously obtained collection of insertion mutants, are presented. The examined mutation proved to be recessive and based on a single insertion of the T-DNA vector pLD3 into the A. thaliana genome. Computer-aided analysis of the DNA region adjacent to the left border of the insertion revealed a putative site of T-DNA insertion, the 2.5-kb At2g09920 gene located in the long arm of chromosome 2, near the centromere.

[Saving insertional recessive lethal mutants of Arabidopsis thaliana]. / Spasenie insertsionnykh retsessivnykh letal'nykh mutantov Arabidopsis thaliana.

A group of 13 recessive lethal mutants was selected on the basis of the collection of Arabidopsis thaliana transgenic plants with insertions of T-DNA vector plasmid pLD3 or pPCVRN4, which was produced by agrobacterial transformation of germinating seeds. The use of media containing exogenous hormones made it possible to compensate the lethal effect, identify phenotypes, and characterize six lines of recessive lethal germlings using genetic and molecular-genetic methods.

[Creation of a collection of morphological insertional mutants of Arabidopsis thaliana]. / Sozdanie kollektsii morfologicheskikh insertsionnykh mutantov Arabidopsis thaliana.

A collection of transgenic Arabidopsis thaliana plants has been obtained by Agrobacterium-mediated transformation. The genomes of the transgenic plants contain insertions of T-DNA of the vector plasmids pLD3 or pPCVRN4. Genes bearing T-DNA insertions were shown to constitute 12-18% of the total number of A. thaliana genes. Seventy-five lines have been chosen from the collection and subjected to genetic and molecular-genetic analysis. Of these, 5 were dominant mutants, and 70, recessive insertion mutants with various morphological defects. Identification of mutant phenotypes and genetic characterization of the transgenic lines have been performed with the use of nutrient media supplemented with exogenous hormones, which revealed five recessive lethal mutants and one dominant sterile mutant.

[Hormone-dependent insertional Arabidopsis thaliana mutants with decreased viability and fertility]. / Gormon-zavisimye insertsionnye mutanty Arabidopsis thaliana so snizhennoi zhiznesposobnost'iu i fertil'nost'iu.

We present data on the phenotype identification and genetic analysis of offspring in three lines of dominant morphological mutants of Arabidopsis thaliana having drastically reduced fertility (a sterile calluslike mutant, a flower mutant, and a dwarf mutant) and in five lines of recessive morphological mutants (four mutants with lethal seedlings and one pigmentation mutant). The mutants were selected from a collection of transgenic plants that had genomes carrying a T-DNA insertion of plasmid vectors pLD3 and pPCVRN4; the collection was created earlier via agrobacterial transformation of germinating seeds. The results presented here were obtained using compensation of hormonal imbalance in the insertional morphological mutants of A. thaliana by exogenous hormones.

[Identification of mutant gene responsible for cotyledons necrosis in developing seedlings of Arabidopsis thaliana]. / Identifikatsiia gena, mutatsiia v kotorom obuslovlivaet vozniknovenie nekrozov semiadolei pri razvitii prorostkov Arabidopsis thaliana.

Genetic and molecular analyses of an Arabidopsis thaliana mutant with necrotic cotyledons from the collection of insertion mutants obtained earlier were conducted. The mutation under study showed incomplete dominance and represented a single insertion of the T region of pLD3 vector used for transformation of germinating seeds to the plant genome during the creation of the collection. Using TAIL-PCR, a fragment of the mutant DNA adjacent to the left border of the T-DNA insertion was isolated and sequenced. Computer r-aided analysis showed that the insertion was located on the left arm of chromosome 1. The open reading frame containing the insertion has one exon and encodes a protein of 446 amino acids, whose functions are unknown.

[Identification of a gene, included in control of root system development in Arabidopsis thaliana]. / Identifikatsiia gena, vkliuchennogo v kontrol' razvitiia kornevoi sistemy u Arabidopsis thaliana.

Genetic and molecular genetic analysis of a lethal root mutant of Arabidopsis thaliana was carried out. The mutant was obtained from a collection created earlier by means of insertion mutagenesis. The mutation was found to be recessive. It was caused by an insertion of the T region of vector pLD3 used for transformation of germinating seeds when creating the collection of insertion mutants. A 118-bp DNA fragment flanking the left border of the insertion was isolated using the TAIL PCR technique, and its nucleotide sequence was determined. Computer analysis of this DNA region demonstrated that it was located in exon 32 of the YUP8HI2R.44 gene in chromosome 1.

[Insertional mutagenesis of Arabidopsis thaliana: increase of germinating seeds transformation efficiency after sonication]. / Insertsionnyi mutagenez Arabidopsis thaliana: uvelichenie éffektivnosti transformatsii prorastaiushchikh semian v rezul'tate predobrabotki ikh ul'trazvukom.

An efficient procedure of transforming Arabidopsis thaliana germinating seeds was elaborated on the basis of the method of Feldmann and Marks. The procedure involves microdamaging T1 seeds by sonication before culturing with a vector Agrobacterium strain and yields more than 1% T2 transformants. Germinating seeds were transformed with Agrobacterium timefaciens hypervirulent strain A281 carrying plasmid pLD3 derived from pBI121. A collection of 54 A. thaliana T2 transformants was obtained; some of them showed marked morphological alterations. The transgenic nature of plants that acquired resistance to a marker antibiotic was confirmed histochemically and by PCR amplification of a T-DNA region.