Heiko Mibus

• PhD
• Head of Department at Geisenheim University

Potted herbs such as basil are in high year-round demand in Central Europe. To ensure good quality in winter, artificial light is required. Many horticulturists, who want to replace their high-pressure‑sodium (HPS) lamps with light-emitting diodes (LEDs) to save electricity energy, struggle with high investment costs. In addition, switching to LEDs...

African indigenous vegetables have a great potential in improving livelihood, offering sustainable food security and solving the malnutrition crisis in sub-Saharan Africa (SSA). African nightshade (Solanum scabrum) is one of such indigenous vegetable, highly appreciated for its nutritive and pharmacological benefits. The vegetable is rich in antiox...

In this study, the influence of different lamp types on physiology and secondary metabolites of Plectranthus scutellarioides (Solenostemon scutellarioides, Coleus blumei) was examined. The following four lamp systems were tested: a new microwave plasma lamp (MPL) emitting artificial sunlight, a commercial high-pressure sodium lamp (HPS), a ceramic...

A large share of cut flowers is produced in Central America or East Africa and marketed in Europe, the USA, and Asia. Due to the increasing conglomeration of production, potted plants also are being shipped over ever-longer distances. It follows that the ability to withstand storage, shipping, and merchandising is an important characteristic of cul...

Cowpea (Vigna unguiculata) plays an important role in sustainable food security and livelihood improvement in Sub-Saharan Africa (SSA). The crop is rich in phytonutrients and minerals, which are key in solving malnutrition and hunger crisis, a major challenge in SSA. However, physiological status, storage temperature and duration affect phytonutrie...

In recent years the concept of "Sustainable Development" has become increasingly relevant in society as well as for the economy. Like in other consumer spending areas, sustainability is getting an increasing role in the ornamental plant production, marketing and consumption. Research in the production area has been focused on achieving a better qua...

In the present work, transgenic Kalanchoë blossfeldiana and Petunia hybrida with overexpression of Nicotiana GA2ox inserted in pCAMBIA1303 T-DNA are investigated. To avoid possible adverse effects of constitutive overexpression a modified Pisum PAL1 promoter was used, in which the BOX-I AC-rich motif had been deleted (dBI—deletion BOX-I). To invest...

In den letzten Jahren hat das Thema Nachhaltige Entwicklung eine immer größere Bedeutung in Wirtschaft und Gesellschaft erlangt. Auch bei der Zierpflanzenproduktion und -vermarktung spielt Nachhaltigkeit eine zunehmend wichtige Rolle (Soode et al., 2015). Dabei stehen Aspekte wie einniedriger Ressourcenverbrauch, Verringerung der Emissionen und ein...

The aim of this study was to establish an efficient virus-induced gene silencing (VIGS) protocol for the gibberellin 2-oxidase gene (GA2ox) in Petunia hybrida 'Fantasy Blue' to measure the reduction in GA2ox transcript levels by quantitative RT-PCR (qRT-PCR) and to investigate the phenotypes of the infected plants. In vitro multiplied Petunia plant...

The discussion and restrictions over the usage of the chemicals in European crop and ornamental plant production implies the search for novel substitute methods. In the present study, we investigate two alternative strategies to induce compact growth in Kalanchoë. First, we examined the possibility of using ethanol as an alternative plant growth re...

Flowers of the complex orchid hybrid Burrageara ‘Stefan Isler Lava Flow’ had been shown previously to react sensitively to ethylene. Via Agrobacterium tumefaciens, the mutant ethylene receptor ETHYLENE RESPONSE 1 (etr1-1) from Arabidopsis thaliana under the control of the flower-specific promoter FLOWER BINDING PROTEIN 1 (fbp1) from Petunia hybrida...

This study is the first report of gene manipulation to alter flower colour in the genus Campanula. The experiment was designed using Campanula carpatica ‘Improved Blue Uniform’ (IBU) with two main purposes: to generate a red flower colour by down-regulation of delphinidin production through RNAi silencing of the flavonoid 3', 5' hydroxylase (F3'5'H...

One of the top targets of recent breeding programs in ornamental plants is focused on developing an alternative way to the chemical growth retardants application in production of plants with compact growth habit. We describe work on Petunia hybrida 'Famous Lilac Dark Vein' plants with overexpreßed MAP kinase 4 nuclear substrate 1 (MKS1) and gibbere...

Impatiens New Guinea hybrids are sensitive to high light conditions, high temperature and low moisture. Consequently, abiotic streß tolerance is one of the main targets of breeders. The aim of this investigation was to characterize the light streß reaction at morphological and physiological level of five Impatiens cultivars and to evaluate chloroph...

Senescence in plants is a complex, genetically determined cell death program that is characterized by protein breakdown, and disintegration of chloroplasts followed by chlorophyll loss. Cytokinins, including aromatic cytokinins and substituted phenyl urea with powerful cytokinin-like activity, are reported to have anti-senescence activities. Hence,...

Ethylene is known to cause many undesirable effects in a range of ornamental plants. Blocking ethylene responses is an efficient strategy to enhance the longevity of flowers and display life of potted plants that are ethylene sensitive. One of the most effective and inexpensive ways to conduct such interference is through the use of chemical compou...

Ethylene has been proved to create adverse effects in ethylene sensitive floriculture crops. A powerful strategy in preventing ethylene responses in ornamentals and subsequently increasing their display life and longevity of flowers is blocking ethylene binding sites. Use of chemical compounds is one of the most efficient and low-cost methods to ex...

The establishment of alternative methods to chemical treatments for growth retardation and pathogen protection in ornamental plant production has become a major goal in recent breeding programmes. This study evaluates the effect of manipulating MAP kinase 4 nuclear substrate 1 (MKS1) expression in Kalanchoë blossfeldiana and Petunia hybrida. The Ar...

Compact growth is a major quality characteristic for the attractiveness and transportation of Kalanchoë, one of most economically important potted plants in Europe. In the present experiments, we examined the possibility of using ethanol as an alternative plant growth regulator. We compared using either an ethanol spray or an ethanol watering treat...

This work describes compact phenotypes of Kalanchoë blossfeldiana and Petunia hybrida plants harboring a constitutively overexpressed gibberellin 2-oxidase (GA 2 ox) transgene. A GA 2 ox gene from Nicotiana tabacum under the control of the Ca35S promoter was introduced into the pCAMBIA1303 plasmid. The cloning vector was introduced into leaf explan...

In situ PCR is a technique, which allows detection of specific nucleic acid sequences in particular cells and tissues. In plants, in situ RT-PCR is widely used in localisation of specific genes, including MADS-box, and other function-specific genes of floral buds and other organs. Roses are one of the most economically important ornamental plants,...

Ethylene biosynthesis is controlled by the enzyme 1-aminocyclopropane-1- carboxylic acid (ACC) synthase. Previous ACC synthase cloning studies revealed a multi-gene family. Degenerate primer pair was used to amplify three DNA fragments using genomic DNA from 'Katinka' leaves. Amplification of several ACC synthase genes with only one PCR reaction wa...

To clarify the molecular mechanism of flower development in Rosa hybrida L. different MADS-box-genes were investigated in normally developed flowers and in malformed flowers (similar C-function mutation). Expression levels of all A, B and C class genes were examined by qRT-PCR in different flower organs of both types of flowers. Expression patterns...

In situ PCR is a technique that allows specific nucleic acid sequences to be detected in individual cells and tissues. In situ PCR and IS-RT-PCR are elegant techniques that can increase both sensitivity and throughput, but they are, at best, only semiquantitative; therefore, it is desirable first to ascertain the expression pattern by conventional...

Pelargonium (Pelargonium x hortorum) is grown as potted or bedding plants for their colourful, showy flowers and scented foliage. Absence of senescence symptoms in the leaves of Pelargonium cuttings, their capacity to initiate roots and continued growth of initiated roots is an important quality attribute. The effects of postharvest treatments with...

One of the effective ways to control ethylene synthesis and ethylene responses in plants is genetic modification. The introduction of the mutant ethylene receptor gene, etr1-1, from Arabidopsis has been proved as the most promising for such purpose, especially when its expression is controlled by a flower specific promoter. Effective regeneration a...

To clarify the molecular mechanism of flower development in Rosa×hybrida L., three different APETALA1/FRUITFULL (AP1/FUL)-like MADS-box genes were isolated and their expression analyzed in normally developed flowers and in malformed flowers of a stable phenotype. AP1/FUL-like genes were designated as RhAP1-1, RhFUL, and RhAP1-2. Alignment of amino...

In many studies cyclopropene compounds have been shown to be effective blockers of ethylene responses in plants. Because of the volatile character of most cyclopropenes, treatment of plant material is limited to enclosed systems. For outdoor applications, non-volatile formulations are desired. In the present study we report the use of newly synthes...

The construct containing the etr1-1 gene from Arabidopsis thaliana under control of the flower specific fbp1-promoter from petunia was used to obtain Campanula carpatica Jacq. potted plants with ethylene insensitive flowers. The flowers on the wild type Campanula plants wilted within three days when exposed to 2 μl L-1 ethylene. The tested transgen...

N,N-dipropyl(1-cyclopropenylmethyl)amine (DPCA), a non-volatile derivative of 1-MCP (1-methylcyclopropene), was synthesized in salt form and tested for effectiveness in preventing ethylene responses in various ornamentals. Individual flowers or flower spikes of four ethylene-sensitive plant species: miniature rose, geranium, carnation and orchid we...

Mannose is an unsuitable carbon source for many plants. Various factors were studied to evaluate the efficacy of mannose in the for production of transgenic plants using Agrobacterium tumefaciens-mediated transformation of leaf explants of Kalanchoe blossfeldiana. To establish a non-antibiotic selection system that utilizes the phosphomannose-isome...

The effects of post harvest application of ethylene, abscisic acid (ABA), indole-3-butyric acid (IBA) treatments or dark storage on root induction and continued growth of regenerated roots in Pelargonium cuttings were investigated using hydroponics in the greenhouse. Ethylene markedly increased rooting percentage in ‘Greco’ and ‘Surfing’, reduced t...

Cyclopropene compounds have been shown to counteract ethylene responses in plants in many studies. They are volatile and for that reason are applied in enclosed systems. However, in some cases, use of a non-volatile formulation would be advantageous. This study reports the use of a novel anti-ethylene formulation, a salt N,N-dipropyl(1-cyclopropeny...

Growth retardation is an important breeding aim and an essential part of horticultural plant production. Here, the potential of transferring the Arabidopsis short internode (shi) mutant phenotype was explored by expressing the AtSHI gene in the popular ornamental plant Kalanchoë. A 35S-AtSHI construct was produced and transferred into eight genetic...

Ethylene plays a crucial role as a coordinator of floral senescence in many ornamental plants, especially during handling and shipping. The most deteriorating effects of ethylene on miniature rose quality appear as leaf yellowing and abscission, petal wilting or flower abscission. Ethylene has a regulatory effect at the transcriptional and translat...

Genetic modification has proved to be an effective way in controlling ethylene synthesis and perception. Use of the mutant ethylene receptor gene, etr1-1, from Arabidopsis seems most promising, especially when it is expressed under the control of a flower specific promoter. In order to introduce the etr1-1 mutant gene in ornamental plant species we...

Kalanchoe blossfeldiana leaf explants were infected and transformed with Agrobacterium tumefaciens harbouring the plasmid pBEO210. This construct contains the mutated ethylene receptor gene etr1-1 from Arabidopsis thaliana under the control of the flower-specific fbp1-promoter from Petunia. Flowers of eight putative transgenic T0 plants exhibiting...

Differential display of mRNA from four sets of contrasting phenotypes were carried out in order to identify and isolate genes associated with elongating growth of Kalanchoë blossfeldiana. A total of 17 unique differential expressed cDNA fragments were sequenced and 12 showed homology to genes in other plant species. Three genes were subsequently te...

Abstract Traditional selection markers used for production of transgenic plants, such as antibiotic resistance, are not acceptable for commercial registration in some countries. Mannose is a promising alternative selective agent, adapted to Agrobacterium tumefaciens-mediated transformation, and regeneration of Kalanchoe blossfeldiana ‘Molly’ and br...

Miniature potted roses are sensitive to ethylene and respond to it by bud and leaf abscission, leaf yellowing and/or flower senescence. The goal of this study was to develop a selection strategy for characterization of ethylene sensitivity in rose breeding lines. Two hundred and thirty-three F1 genotypes were obtained from a reciprocal crossing of...

Using differential display we isolated five ethylene-responsive cDNAs from Rosa hybrida L. and identified for the first time an ethylene-induced cDNA homologous to a laccase gene. Three cDNAs were isolated from petioles and two cDNAs from pedicels. Expression levels of all cDNAs in pedicels were higher than in petioles. The laccase homolog cDNA was...

Adult plants are known for recalcitrance when it comes to adventitious organ formation and regeneration. Methods used for regeneration in explants from seedlings of Campanula carpatica failed to work for explants from adult plants of the same species. The present investigation generated efficient regeneration methods for mature specimens of four sp...

Transgenic Kalanchoe blossfeldiana Poelln. with reduced ethylene sensitivity in flowers was obtained by Agrobacterium tumefaciens-mediated transformation using the plasmid pBEO210 containing the mutant ethylene receptor gene etr1-1 from Arabidopsis thaliana under the control of the flower-specific fbp1-promoter from Petunia. Three ethylene-resisten...

Pre-treatment of Kalanchoë blossfeldiana Poelln. 'Alexandra' flowers with 1- decylcyclopropene (1-DCP), an ethylene action inhibitor, delayed inrolling and prolonged the display life of flowers. 1-DCP was the most effective at concentration of 200 nl L-1, similar to 1-methylcyclopropene (1-MCP) used as standard/control. However, 1-DCP treatment ext...

Ethylene has been known to cause many undesirable effects in a range of ornamental species. Blocking ethylene responses has been proved as an efficient strategy to enhance the longevity of the flowers. The most effective ways to conduct such interference are using chemical compounds or genetic manipulation. In the last 15 years a large number of vo...

Expression of ACC synthase and ethylene receptor (ETR) genes were evaluated in different organs of Pelargonium and in response to treatment of leaves with TDZ, ethylene, ABA or exposure to darkness. To isolate unknown ACS genes, a degenerate primer pair was used to amplify three DNA fragments using genomic DNA from Pelargonium leaves. Sequence anal...

Fertile transgenic Campanula carpatica Jacq. plants with flowers, which had reduced sensitivity to ethylene were obtained by Agrobacterium tumefaciens that mediated transformation. The construct used for transformation contained the etr1-1 gene from Arabidopsis thaliana under control of the flower specific fbp1-promoter from petunia. More than 100...

The miniature potted roses are popular greenhouse crops in many parts of the world. In the 1980s the introduction of new varieties had a dramatic impact on the European and North American markets. Current world production is estimated at around 100 million pots yearly. Major centers of production include Denmark, the Netherlands, the United States,...

The cucumber with five sex types attracted researcher to consider it as a model plant for the sex-determination studies. In combination with environmental factors, three major genes (F/f, M/m and A/a) influence the formation of different sex types. The correlation between the F-allele and femaleness as well as high level of ethylene is already esta...

The effects of post-harvest treatments with thidiazuron (TDZ), ethylene and abscisic acid (ABA), and dark storage of Pelargonium cuttings were investigated. TDZ-treatment markedly delayed the onset of leaf senescence in cultivars 'Fire', 'Katinka' and 'Ganymed'. Storing the cuttings in the dark for 4 d and/or treating them with 2 μl l-1 ethylene or...

Ornamental plants represent a high number of species from different plant families. To investigate the ethylene biosynthesis and isolate the genes involved in each species a fast and simple method is necessary. The enzyme that controls the ethylene synthesis is the 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, which catalyses the formation...

1-Octylcyclopropene (1-OCP) and 1-Decylcyclopropene (1-DCP), ethylene receptor inhibitors, analogues to 1-MCP, substituted with longer carbon chain in the 1-position were investigated in miniature potted roses cultivar ’Lavender‘. All levels of both chemicals protected as compared to untreated plants. 1-OCP and 1-DCP were the most effective at conc...

The biological processes leading to sex expression in plants are of tremendous practical significance for fruit production of many agricultural and horticultural crops. Sex-expression studies in cucumber showed that the different sex types are determined by three major genes: M/m, F/f and A/a. The M/m gene in the dominant condition suppresses stami...

In cucumber plants sex is determined by three major genes, F/f, M/m and A/a. In addition to these genes other factors such as plant hormones also influence sex expression. Amongst plant hormones, ethylene is thought to be the sex hormone in the cucumber plants (YIN and QUINN 1995). Series of studies have been carried out to investigate the relation...

The cucumber (Cucumis sativus) with its diversity of sex types represents a perfect model plant for studying sex expression. Besides environmental factors, three major genes, Acr/acr, M/m, and A/a are responsible for the different sex types of cucumber. According to the one-hormone hypothesis, formation of the four sex types of cucumber can be expl...

The use of the PMI/ mannose selection system to recover transgenic sweet orange plants (Citrus sinensis L. Osbeck). Plant Cell Reports, 22: 122-128. bRAndt P. (2001) Die neue Generation von Marker-Genen zum frühen Erkennen von genetisch veränderten Pflanzen. Bundesge-sundheitsbl-Gesundheitsforsch-Gesundheitsschutz, 44: 1188-1193. dAle e. c., oW D....

Hannover, Universiẗat, Diss., 2003 (Nicht für den Austausch).