ERC FUNDED PROJECTS

Many aphid species are restricted to one or few host plants, while some aphids, many of which are of agricultural importance, can infest a wide range of plant species. An important observation is that aphids spend a considerable time on nonhost species, where they probe the leaf tissue and secrete saliva, but for unknown reasons are unable to ingest phloem sap. This suggest that aphids, like plant pathogens, interact with nonhost plants at the molecular level, but potentially are not successful in suppressing plant defenses and/or releasing nutrients. To date, however, the plant cellular changes and the involvement of immune response, such as ETI and PTI, in aphid-host and -nonhost interactions remain elusive. The aim of the proposed project is to gain insight into the level of cellular host reprogramming that takes place during aphid-host interactions, the cellular processes involved in aphid nonhost resistance, and the role of aphid effectors in determining host range. We will compare interactions of two economically important aphid species, Myzus persicae (green peach aphid) and Rhopalosiphum padi (bird cherry oat aphid), with host and nonhost plants. We will investigate local changes in plant cellular processes during aphid-host and -nonhost interactions using microscopy and biochemistry approaches. We will apply a comparative transcriptomics approach and functional assays to identify aphid effectors as potential determinants of host range. Herein we will specifically looks for aphids-species specific effectors and those that are expressed in specific host interactions. To gain insight into molecular mechanisms of effector activities we will identify host targets and investigate the contribution of effector-target interactions to host range. The expected outcomes of the project will, in the long term, contribute to the development of novel strategies to control infestations by aphids and potentially other pests and pathogens, thereby improving food security.

1 463 840 €

Start date: 2013-02-01, End date: 2018-10-31

New renewable energy source are highly needed to compensate exhausting fossil fuels reserves and reduce greenhouse gases emissions. Some species of algae have an interesting potential as feedstock for the production of biodiesel thanks to their ability to accumulate large amount of lipids. Strong research efforts are however needed to fulfil this potential and address many issues involving optimization of cultivation systems, biomass harvesting and algae genetic improvement. This proposal aims to address one of these issues, the optimization of algae light use efficiency. Light, in fact, provides the energy supporting algae growth and must be exploited with the highest possible efficiency to achieve sufficient productivity. In a photobioreactor algae are highly concentrated and this cause a inhomogeneous light distribution with a large fraction of the cells exposed to very low light or even in the dark. Algae are also actively mixed and they can abruptly move from dark to full illumination and vice versa. This proposal aims to assess how alternation of dark/light cycles affect algae growth and functionality of photosynthetic apparatus both in batch and continuous cultures. In collaboration with the Chemical Engineering department, experimental data will be exploited to build a model describing the photobioreactor, a fundamental tool to improve its design. The other main scope of this proposal is the isolation of genetically improved strains more suitable to the artificial environment of a photobioreactor. A first part of the work of setting up protocols for transformation will be followed by a second phase for generation and selection of mutants with altered photosynthetic performances. Transcriptome analyses in different light conditions will also be instrumental to identify genes to be targeted by genetic engineering.

1 257 600 €

Start date: 2012-10-01, End date: 2017-09-30

Agriculture depends on breeding. Breeders try to combining desirable and eliminating unfavourable traits of crop plants. Changes in genetic linkage are based on meiotic recombination. Although techniques for the transfer of single traits have been developed, resulting in genetically modified organisms (GMOs), hardly any effort has been undertaken to control the exchange between parental genomes as such. By applying new molecular tools to control recombination the current project aims to establish a new kind of ¿designed¿ plant breeding. Thus, not only transfer or elimination of specific traits should become possible in a programmable way, but also the access to the complete gene pool of natural species and its widening by crossing in closely related species should become feasible. Suppression of recombination should result in an apomixis-like propagation of elite cultivars. Mainly two different levels of control will be addressed in the project: the induction of recombination at predefined specific sites in the genome and the regulation of the level of genome-wide exchange. For the former approach we will apply specifically tailored sequence-specific zinc-finger and meganucleases. Global changes should be achieved by modulating the expression of factors involved in the resolution of recombination intermediates. As the strategy relies on the exploitation of the natural mechanism of recombination, biotechnologically improved plants without transgenes will be obtained after outcrossing. Thus, public concerns raised by GMOs brought out in the field should be avoided. As recent technical improvements make the elucidation of genomic sequences possible at moderate cost and time requirements, the setup of ¿designed¿ breeding should become especially useful in the near future.

2 493 000 €

Start date: 2011-09-01, End date: 2016-08-31

Massive amounts of dust (~1 Billion Ton) are blown from the Sahara into and over the Atlantic Ocean every year. This dust strongly alters the atmosphere through blocking incoming solar radiation [cooling the atmosphere] and trapping outgoing heat that was reflected at the earth’s surface [warming the atmosphere]. In addition, aerosols carry huge amounts of metals and nutrients that can boost marine life, but also vast amounts of microbes, spores, and pathogens that are harmful for both marine- and terrestrial (including human!) life. The net effect of cooling/warming and ocean fertilisation/poisoning is presently far from understood as it depends on a complex set of parameters related to dust emission, dispersal, and deposition. In order to quantify these parameters, I propose to develop and apply a novel approach to study the transatlantic flux of Saharan dust and its environmental effect on the ocean by deploying a transect of seven ocean moorings with a dust-collecting surface buoy below the Saharan dust plume from NW Africa to the Caribbean. Sampling dust in air as well as under water at a biweekly resolution for initially one complete year will for the first time allow to: 1) quantify the seasonal variability in Saharan dust export into the Atlantic, 2) distinguish between high-altitude summer plumes versus low-level winter trade-wind transport, 3) quantify source-to-sink changes in particle size and the related (metal, nutrient, and biological-) composition of the dust, and 4) determine the in situ bio-availability of the associated nutrients and their potential fertilisation of the photic zone. These unique, seasonally and spatially resolved data will bridge the gap between the bi-weekly sediment-trap record off Cape Blanc (NW Africa, since '85) and the daily dust fluxes recorded on Barbados (Caribbean, since '73). Subsequently, the data can be extrapolated back in time in marine sediments, which are an archive for dust transport and carbon pump in the past.

1 972 839 €

Start date: 2012-10-01, End date: 2017-09-30