Transgenic apple plants overexpressing the Lc gene of maize show an altered growth habit and increased resistance to apple scab and fire blight.

Transgenic apple plants (Malus x domestica cv. 'Holsteiner Cox') overexpressing the Leaf Colour (Lc) gene from maize (Zea mays) exhibit strongly increased production of anthocyanins and flavan-3-ols (catechins, proanthocyanidins). Greenhouse plants investigated in this study exhibit altered phenotypes with regard to growth habit and resistance traits.

Purification and characterisation of a jacalin-related, coleoptile specific lectin from Hordeum vulgare.

A plant lectin was isolated from barley (Hordeum vulgare) coleoptiles using acidic extraction and different chromatographic methods. Sequencing of more than 50% of the protein sequence by Edman degradation confirmed a full-length cDNA clone. The subsequently identified open reading frame encodes for a 15 kDa protein which could be found in the soluble fraction of barley coleoptiles.

Identification of differentially expressed genes in Malus domestica after application of the non-pathogenic bacterium Pseudomonas fluorescens Bk3 to the phyllosphere.

Biological control of plant diseases by the application of antagonistic micro-organisms to the plant phyllosphere is only marginally understood. Suppression subtractive hybridization (SSH) was used for the identification of genes expressed after application of the non-pathogenic bacterium Pseudomonas fluorescens Bk3 to the phyllosphere of the apple scab-susceptible cultivar Malus domestica cv. Holsteiner Cox.

Characterization by suppression subtractive hybridization of transcripts that are differentially expressed in leaves of apple scab-resistant and susceptible cultivars of Malus domestica.

In order to compare transcription profiles in cultivars of Malus domestica that are differentially sensitive to apple scab (Venturia inaequalis), two cDNA libraries were constructed using the suppression subtractive hybridization (SSH) method. Subtraction hybridization was performed between cDNAs from uninfected young leaves of the resistant cultivar Remo and the susceptible Elstar. In total, 480 EST clones were obtained: 218 (ELSTAR) clones represent transcripts that are preferentially expressed in Elstar, while the other 262 (REMO) are derived from RNAs that are more highly expressed in Remo.

Purification and partial characterization of an extracellular melanoprotein from the fungus Venturia inaequalis.

The fungus Venturia inaequalis clone No. 36 isolated from Malus domestica cv. Gloster excretes a melanoprotein of 36 kDa in relatively high amounts during growth in liquid culture.

Up-regulation of pathogenesis-related proteins in the apoplast of Malus domestica after application of a non-pathogenic bacterium.

The intercellular washing fluid (IWF) of Malus domestica cv. Holsteiner Cox before and after application of the non-pathogenic bacterium Pseudomonas fluorescens Bk3 to the leaves was investigated in a comparative manner. SDS-PAGE in combination with ESI Q-ToF mass spectrometry, and homology search in relevant data bases revealed the highly up-regulated expression of several pathogenesis-related plant proteins in the apoplast of the leaves treated with P.

Investigations on epiphytic living Pseudomonas species from Malus domestica with an antagonistic effect to Venturia inaequalis on isolated plant cuticle membranes.

In order to understand better the survival and mutual interaction of epiphytic bacteria and fungi on apple plants, bacteria collected from these plants were cultivated on intact adaxial, stoma free cuticle membranes originally obtained from apple. The bacteria were labelled with luciferase genes from Vibrio harveyi in order to follow up their development and activity on the isolated cuticles. Our finding was that the epiphytic bacteria can have access to nutrients below the cuticle without causing damage to these cuticular membranes.

Non-invasive determination of plant-associated bacteria in the phyllosphere of plants.

Epiphytic living Pseudomonas strains isolated from different Malus domestica cultivars were transformed with two reporter genes [green fluorescent protein (gfp) and luciferase (luxAB)]. The establishment and distribution of these bacteria on sterile, in vitro-propagated, and thus genetically identical, Malus domestica plants were continuously analysed with a cooled, back-illuminated, charge-coupled-device (CCD) camera system. The combination of the assessment of bioluminescence and the use of a CCD camera offer an intriguing method to study, non-invasively and in real time, plant-microbe interactions as well as the colonization of the phyllosphere by microorganisms.