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Abstract

The behavior of the autonomous maize transposable element En/Spm of maize was studied in Arabidopsis. Transgenic Arabidopsis plants carrying En-1 elements were propagated for 12 generations using a single seed descent procedure. The distribution and activity of the En-1 element was monitored using Southern DNA hybridisations in generations 1, 6 and 12. In the first generation the highest number of En-1 insertions per line was 7, which increased to 20 in generation 12. The average number of En-1 insertions increased only slightly in the population, due to a gradual accumulation of segregants that lost the transposable element. During the development of the En-1 mutagenised population the element remained active even in the high-copy lines. In situ hybridisation demonstrated that multiple En-1 insertions were distributed over all Arabidopsis chromosomes. From the initial En-1 mutagenised populations many unstable gene mutations were recovered, indicating that En-1 can be used as a efficient tool for gene tagging in Arabidopsis.

Postgerminative growth and lipid catabolism in oilseeds lacking the glyoxylate cycle

“…Genomic DNA pools from an En͞Spm transposon-tagged Arabidopsis (ecotype Col0) mutant population (13), consisting of Ϸ48,000 En-1 insertions, were screened by PCR for a knockout in ICL (GenBank accession no. AB025634).…”

“…The gene-specific primers ICL51 (5Ј-GCAGAGG-GAGGCA AGA ATGAGCATG) and ICL31 (5Ј-TA A-CACTCGGCCTTGCTCATTTGAC) were used in combination with En-1 border primers En8130 and En250 (see ref. 13). Two mutant alleles (icl-1 and icl-2) were identified, and the insertion sites were mapped by sequencing PCR products spanning the borders.…”

“…Only one ICL gene has been identified in Arabidopsis, and Southern blot analysis supports the presence of a single gene copy (data not shown). By using a PCR-based reverse-genetic screen, two independent mutants (icl-1 and icl-2) were isolated from an Arabidopsis population carrying the autonomous En͞ Spm transposable element from maize (13). The borders of the En-1 element are situated 1,225 bp 3Ј of the start of translation in icl-1, whereas in icl-2 the element is in the reverse orientation, inserted at 1,611 bp.…”

KAT1 is not essential for stomatal opening

“…For functional analysis of the KAT1 gene, we screened for a knockout mutant in a collection of Arabidopsis plants mutagenized by the maize transposon En-1 (21). In a reverse genetic approach (22) employing a combination of KAT1-and En-1-specific PCR-primers, we identified the mutant KAT1::En-1 7AAD31 (Fig.…”

“…Even though the inward-rectifying K ϩ channel KAT1 has been cloned (14), characterized in oocytes (15)(16)(17)(18), and shown to express in guard cells (19), its impact for the functional K ϩ channel in the plasma membrane of guard cells is still unknown (20). To analyze the physiological role of the KAT1 channel in planta, we have isolated a mutant in the KAT1 gene by using transposon mutagenesis (21). We show that disruption of the KAT1 gene does not affect stomatal opening, although underlying potassium currents were altered.…”