Physiologische und molekulargenetische Charakterisierung der Geschlechtsausprägung bei der Gurke (Cucumis sativus L.) : unter besonderer Berücksichtigung der Ethylensynthese und der Ethylensignaltransduktion

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Localisation of Abundant and Organ-Specific Genes Expressed in Rosa hybrida Leaves and Flower Buds by Direct In Situ RT-PCR

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 means to establish the suitable conditions for each probe. In plants, in situ RT-PCR is widely used in the expression localisation of specific genes, including MADS-box and other function-specific genes or housekeeping genes in floral buds and other organs. This method is especially useful in small organs or during early developmental stages when the separation of particular parts is impossible. In this paper, we compared three different labelling and immunodetection methods by using in situ RT-PCR in Rosa hybrida flower buds and leaves. As target genes, we used the abundant β-actin and RhFUL gene, which is expressed only in the leaves and petals/sepals of flower buds. We used digoxygenin-11-dUTP, biotin-11-dUTP, and fluorescein-12-dUTP-labelled nucleotides and antidig-AP/ streptavidin-fluorescein-labelled antibodies. All of the used methods gave strong, specific signal and all of them may be used in localization of gene expression on tissue level in rose organs

Manipulation of MKS1 gene expression affects Kalanchoe blossfeldiana and Petunia hybrida phenotypes

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 Kalanchoe blossfeldiana and Petunia hybrida. The Arabidopsis thaliana MKS1 gene was overexpressed in both species via Agrobacterium-mediated transformation, resulting in dwarfed phenotypes and delayed flowering in both species and increased tolerance to Pseudomonas syringae pv. tomato in transgenic Petunia plants. The lengths of the stems and internodes were decreased, while the number of nodes in the transgenic plants was similar to that of the control plants in both species. The transgenic Kalanchoe flowers had an increased anthocyanin concentration, and the length of the inflorescence stem was decreased. The morphology of transgenic Petunia flowers was not altered. The results of the Pseudomonas syringae tolerance test showed that Petunia plants with one copy of the transgene reacted similarly to the nontransgenic control plants; however, plants with four copies of the transgene exhibited considerably higher tolerance to bacterial attack. Transgene integration and expression was determined by Southern blot hybridization and RT-PCR analyses. MKS1 in wild-type Petunia plants was down-regulated through a virus-induced gene silencing (VIGS) method using tobacco rattle virus vectors. There were no significant phenotypic differences between the plants with silenced MKS1 genes and the controls. The relative concentration of the MKS1 transcript in VIGS-treated plants was estimated by quantitative RT-PCR

Production of compact plants by overexpression of AtSHI in the ornamental Kalanchoe

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 Kalanchoe A 35S-AtSHI construct was produced and transferred into eight genetically different cultivars of Kalanchoe by Agrobacterium tumefaciens The resulting transgenic plants showed dwarfing phenotypes like reduced plant height and diameter, and also more compact inflorescences, as a result of increased vegetative height The shi phenotype was stable over more than five vegetative subcultivations Compared with Arabidopsls, the ectopic expression of AtSHI in Kalanchoe showed several differences None of the Kalanchoe SHI-lines exhibited alterations in leaf colour or morphology, and most lines were not delayed in flowering Moreover, continuous treatment of lines delayed in flowering with low concentrations of gibberellins completely restored the time of flowering These features are very Important as a delay in flowering would increase plant production costs significantly. The effect of expression controlled by the native Arabidopsls SHI promoter was also investigated in transgenic Kalanchoe and resulted in plants with a longer flowering period Two AtSHI like genes were identified in Kalanchoe indicating a widespread presence of this transcription factor These findings are important because they suggest that transformation with the AtSHI gene could be applied to several species as a tool for growth retardation, and that this approach could substitute the use of conventional chemical growth regulation in plant productio

Development stage, storage temperature and storage duration influence phytonutrient content in cowpea (Vigna unguiculata L. Walp.)

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 phytonutrient levels and postharvest life of the leafy vegetable. Despite the significant importance of cowpeas, the maturity and postharvest storage effects on quality of the leafy vegetable remains unrevealed. The aim of this study was to analyze the dynamics of phytonutrients in cowpea leaves during development under field conditions in Kenya and in storage. The total carbohydrates (glucose, fructose, sucrose and starch) were highest at 90 d after planting (105.9 ± 2.5 g kg-1) compared to 30, 60 and 120 d. The total Phenolics (Gallic acid equivalents) increased gradually with age up to 12.0 ± 0.2 g kg-1 by 120 d. Catechin equivalent flavonoids, trolox equivalent antioxidants (TEA) and chlorophyll were highest in concentrations at 60 d after planting with 8.0 ± 0.5 g kg-1, 26.19 ± 0.5 g kg-1 and 5.7 ± 0.4 g kg-1 respectively. Quercetin equivalent flavonoids and total carotenoids did not show significant changes with age, while mineral concentration dynamics were specific for each element. Storage of cowpea leaves at room temperature (50–55 % relative humidity) led to a stronger decline of phytonutrients after 4 d, but mostly they remained stable at cold storage (5 °C). Results of this study highlight the importance of developmental stage at harvest, storage conditions and duration for the optimal availability of phytonutrients in freshly consumed leaves and for postharvest management strategies