Using nitrogen from the air may well not be limited to legumes in future
(Molecular biology)
Almost all plants possess the molecular and cell biological requirements to fixate nitrogen from the air, just like legumes do. Research showed the similarity of the rhizobium symbiosis in legumes and the symbiosis with mycorrhizae of other plant species. This implies that many plants are more or less pre-equipped for symbiosis with rhizobium and thus for nitrogen fixation from the air. This result may be of large impact for future agriculture. Plants that are able to ‘harvest’ nitrogen from the air need less fertilisers and are thus a more sustainable source of food and plant based raw materials.

Mind the enemy of the enemy of your enemy!
(Entomology)
Plants under attack of caterpillars call for help by the production of volatile compounds that attract parasitic wasps. These wasps help the plant to limit the damage. These compounds can also be detected by other insects. A recent study shows that other parasitic wasp use these compounds to find the parasitic wasps they need for their reproduction. Using parasitic wasps can be an effective approach for biological control of pests, but efforts to optimize this using plant produced volatile compounds may therefore work counterproduictive.

Well performing internal logistics crucial for directed growth of plants
(Cell biology)
In plant cells, actin filament bundles serve as tracks for organelle movement using myosin proteins as an ‘engine’. This movement can be observed in the cytoplasm using a simple light microscope. In this study we blocked the actin-bundling protein villin, which leads to thin bundles only and individual actin filaments. Blocking the transport this way allows the plant to grow but makes the directed growth of plant organs like leaves more variable. This shows that sub cell logistics are of importance to the directed growth of plant organs.

• Plant Physiology: Arabidopsis VILLIN2 and VILLIN3 are required for the generation of thick actin filament bundles and for directional organ growth

• Biosystems Engineering: A methodology for model-based greenhouse design: Part 5, greenhouse design optimisation for southern-Spanish and Dutch conditions

'Flip-flop' switch discovered for asymmetric cell division
(Plant Developmental Biology)
For growth and development, organisms must produce tissues with distinct functions. These different tissues are derived from stem cells. How stem cells divide to create new cell types is known as asymmetric cell division, and is obviously crucial to the overall development of the organism. In plants, whose cells cannot migrate, the location where a stem cell undergoes asymmetric cell division is also crucial, since it ensures that these tissues develop in the correct place. Mathematical modeling showed that in roots asymmetric cell divisions are only switched on after integration of radial and longitudinal information, determined by a translation factor and auxin distribution, respectively. Coupling of cell-cycle progression to protein degradation resets the circuit, resulting in a flip flop that constrains asymmetric cell division to the stem cell region.

• Cell: A Bistable Circuit Involving SCARECROW-RETINOBLASTOMA Integrates Cues to Inform Asymmetric Stem Cell Division

Why is there genetic variation in photosynthesis of rice and does it help?
(CSA: Crop Physiology)
Photosynthesis of rice was dissected into stomatal conductance, mesophyll conductance, electron transport capacity and Rubisco carboxylation capacity. The genetic variation was mainly associated with the genetic variation in stomatal conductance and mesophyll conductance. The impact of environmental factors on photosynthesis is mainly associated with effects on stomatal and mesophyll conductances and now we have found evidence that apparently the genetic variation works through the same types of influences. Moreover, we have found that virtual ideotypes can have a 17.0% higher photosynthesis and a 25.1% higher transpiration efficiency than the best genotype investigated.

• Journal of Experimental Botany: Physiological basis of genetic variation in leaf photosynthesis among rice (Oryza sativa L.) introgression lines under drought and well-watered conditions
  
  

Better crops by smarter use of marker and pedigree information
(Biometris)
How to breed for better crops in a short time? Breeding companies do so by designing multiple crosses for variety selection and detection of chromosomal regions of interest. A big breeding company contracted Biometris to help making better use of the data of their breeding program. Biometris developed an quick, efficient and patented way to exploit the relatedness of parents in multiple connected crosses. By capturing the ancestral marker and pedigree information in to local identity-by-descent matrices, the power and accuracy of detection of chromosomal regions of interest was significantly improved, without increasing the computational demand of the Bayesian analysis.

• TAG Theoretical and Applied Genetics: QTL linkage analysis of connected populations using ancestral marker and pedigree information

Phosphate problem less urgent than expected
(Plant production systems)
Producing sufficient and proper food for the global population in 2050 will probably require 40% less phosphate than was previously assumed, which means that the phosphate supply will last longer than expected. This is the conclusion of research carried out by Wageningen University and published in the scientific magazine PNAS. For the first time the scientists used computer models capable of taking into account the amount of phosphate left behind in the soil after harvesting a fertilised crop. This enabled a more precise calculation of the required quantity of phosphate, particularly for land on which more phosphate than necessary has been used for years on end.

• Proceedings of the National Academy of Sciences of the USA (PNAS): Residual soil phosphorus as the missing piece in the global phosphorus crisis puzzle
  
  

Mosquito immunity squashed by West Nile virus
(Virology)
West Nile and dengue viruses are transmitted by blood-sucking mosquitoes and pose a serious threat to human health. During infection, these viruses produce a non-coding viral RNA that is required for pathogenicity. The Laboratory of Virology of Wageningen University now shows that this non-coding viral RNA is a decoy molecule for Dicer and shuts down the mosquito immune system. This research explains how West Nile and dengue viruses can productively replicate in mosquitoes for subsequent transmission to humans.

• Journal of Virology: Noncoding Flavivirus RNA Displays RNAi Suppressor Activity in Insect and Mammalian Cells

Complex agro-ecosystems can support food security in a changing climate
(Farming Systems Ecology)

Complex agro-ecosystems can support ecological processes of nutrient cycling and pest control, which may lead to higher and more stable yields. Research showed that enhancing the complexity of a rice production system by adding combinations of compost, azolla, ducks and fish resulted in strongly increased grain yields and revenues in a season with extremely adverse weather conditions on East Java, Indonesia. In the most complex system comprising all components the highest grain yield was obtained. If smallholders can be trained to manage these systems and are supported for initial investments by credits, their livelihoods can be improved while producing in an ecologically way.

• Ecology and Evolution: Complex agro-ecosystems for food security in a changing climate

International consortium unravels tomato genome
(Bioscience)
Wageningen UR (University & Research centre) and KeyGene together with their partners in the Tomato Genome Consortium (TGC) have sequenced the genomes of the domesticated tomato and its wild ancestor, Solanum pimpinellifolium. This achievement is expected to lower costs and speed up efforts to improve the worldwide tomato production, making it better equipped to combat pests, pathogens, droughts and diseases that plague growers. The work may also speed up improvements to other crops.

• Nature: The tomato genome sequence provides insights into fleshy fruit evolution