The ethylene precursor ACC affects early vegetative development independently of ethylene signaling

The plant hormone ethylene plays a pivotal role in virtually every aspect of plant development, including vegetative growth, fruit ripening, senescence, and abscission. Moreover, it acts as a primary defense signal during plant stress. Being a volatile, its immediate biosynthetic precursor, 1-aminocyclopropane-1-carboxylic acid, ACC, is generally employed as a tool to provoke ethylene responses. However, several reports propose a role for ACC in parallel or independently of ethylene signaling. In this study, pharmacological experiments with ethylene biosynthesis and signaling inhibitors, 2-aminoisobutyric acid and 1-methylcyclopropene, as well as mutant analyses demonstrate ACC-specific but ethylene-independent growth responses in both dark- and light-grown Arabidopsis seedlings. Detection of ethylene emanation in ethylene-deficient seedlings by means of laser-based photoacoustic spectroscopy further supports a signaling role for ACC. In view of these results, future studies employing ACC as a proxy for ethylene should consider ethylene-independent effects as well. The use of multiple knockout lines of ethylene biosynthesis genes will aid in the elucidation of the physiological roles of ACC as a signaling molecule in addition to its function as an ethylene precursor

Insights into the Evolution of Multicellularity from the Sea Lettuce Genome

We report here the 98.5 Mbp haploid genome (12,924 protein coding genes) of Ulva mutabilis, a ubiquitous and iconic representative of the Ulvophyceae or green seaweeds. Ulva’s rapid and abundant growth makes it a key contributor to coastal biogeochemical cycles; its role in marine sulfur cycles is particularly important because it produces high levels of dimethylsulfoniopropionate (DMSP), the main precursor of volatile dimethyl sulfide (DMS). Rapid growth makes Ulva attractive biomass feedstock but also increasingly a driver of nuisance “green tides.” Ulvophytes are key to understanding the evolution of multicellularity in the green lineage, and Ulva morphogenesis is dependent on bacterial signals, making it an important species with which to study cross-kingdom communication. Our sequenced genome informs these aspects of ulvophyte cell biology, physiology, and ecology. Gene family expansions associated with multicellularity are distinct from those of freshwater algae. Candidate genes, including some that arose following horizontal gene transfer from chromalveolates, are present for the transport and metabolism of DMSP. The Ulva genome offers, therefore, new opportunities to understand coastal and marine ecosystems and the fundamental evolution of the green lineage

Biodiversity of soils and farming innovations for improved resilience of European wheat agrosystems (BIOFAIR)

BIOFAIR holistically determines soil biodiversity under different farming practices and environmental stressors to anticipate negative impacts of climate change on belowground processes and provide adaptation strategies. The BIOFAIR project comprehensively addresses the diversity of soil organisms, from microbes to mites, and how they link to soil functioning in terms of disease suppression and carbon and nutrient cycling. On the crop site, a specific focus is given to grain quality parameters such as vitamin and mineral nutrient contents essential for many human body functions, and to technological bread making properties such as flour viscosity, to ensure the crops of the future have a high nutritious value and are suitable for food production.2. Zero hunger3. Good health and well-being12. Responsible consumption and production13. Climate action15. Life on land17. Partnerships for the goal

Biodiversity of soils and farming innovations for improved resilience of European wheat agrosystems (BIOFAIR)

IOFAIR holistically determines soil biodiversity under different farming practices and environmental stressors to anticipate negative impacts of climate change on belowground processes and provide adaptation strategies. The BIOFAIR project comprehensively addresses the diversity of soil organisms, from microbes to mites, and how they link to soil functioning in terms of disease suppression and carbon and nutrient cycling. On the crop site, a specific focus is given to grain quality parameters such as vitamin and mineral nutrient contents essential for many human body functions, and to technological bread making properties such as flour viscosity, to ensure the crops of the future have a high nutritious value and are suitable for food production

Accumulation and Transport of 1-Aminocyclopropane-1-Carboxylic Acid (ACC) in Plants: Current Status, Considerations for Future Research and Agronomic Applications

1-aminocyclopropane-1-carboxylic acid (ACC) is a non-protein amino acid acting as the direct precursor of ethylene, a plant hormone regulating a wide variety of vegetative and developmental processes. ACC is the central molecule of ethylene biosynthesis. The rate of ACC formation differs in response to developmental, hormonal and environmental cues. ACC can be conjugated to three derivatives, metabolized in planta or by rhizobacteria using ACC deaminase, and is transported throughout the plant over short and long distances, remotely leading to ethylene responses. This review highlights some recent advances related to ACC. These include the regulation of ACC synthesis, conjugation and deamination, evidence for a role of ACC as an ethylene-independent signal, short and long range ACC transport, and the identification of a first ACC transporter. Although unraveling the complex mechanism of ACC transport is in its infancy, new questions emerge together with the identification of a first transporter. In the light of the future quest for additional ACC transporters, this review presents perspectives of the novel findings and includes considerations for future research toward applications in agronomy

Mix-and-match : an improved, fast and accessible protocol for hypocotyl micrografting of Arabidopsis seedlings with systemic ACC responses as a case study

Background Grafting is a technique widely used in horticulture that also has been applied in agriculture. In plant physiology, grafting facilitates the elucidation of mechanisms underlying growth and developmental processes, through the construction of chimeric plants with organs of different genotypes. Despite its small size, the model species Arabidopsis thaliana is very amenable for grafting, which can be useful to investigate transport of nutrients, amino acids or secondary metabolites between different tissues, or to investigate developmental processes depending on root-to-shoot communication, such as shoot branching, root and shoot plasticity upon shade avoidance, or disease resistance. Nevertheless, grafting protocols are usually technically challenging and training is required to achieve a reasonable success rate. Additionally, specialized tools and equipment are often needed, such as chips to accommodate the grafted plantlets or collars to maintain the contact between root and shoot. Results In this methodology paper, we provide a fast, easy, accessible, and specialized equipment-free protocol that enables high success ratios. Critical steps and notes are detailed, easing the implementation of the procedure for non-trained researchers. An example of the protocol application by three independent non-trained researchers shows that this method allows to achieve a 90–100% of grafting efficiency after 6 days post-grafting recovery. In addition, the grafting of Col-0 with the acs8x mutant, depleted in 1-aminocyclopropane-1-carboxylic acid (ACC), the biosynthetic precursor of the phytohormone ethylene, provides an example of the application of this optimized protocol, showing the suitability of the process to study long-distance transport processes. Conclusions We present an optimized protocol for hypocotyl grafting of 4-day-old Arabidopsis thaliana seedlings. The combination of conditions yields a grafting success of 90–100% and provides an easy and accessible methodology, reducing the time frame, and without the necessity of acquiring specialized equipment. The presented protocol is simple, fast and highly efficient, easing the inclusion of hypocotyl grafting assays in any research project. In addition, the description of the protocol is detailed to a level ensuring that even non-trained researchers, are sufficiently prepared to adopt the grafting methodology

A Usability Study of Friendlyreader Webb

Syftet med mitt examensarbete är att undersöka användbarheten i FriendlyReader Web. Programmet är en e-tjänst som underlättar förståelse och överblick av digital materialet som textdokument, PDF m.m. Användbarheten har att testas genom att mäta ögonrörelser på 10 dyslektiker och 20 icke-dyslektiker. Vid ögonrörelsemätningar fick användarna utföra tre olika uppgifter i FriendlyReader Web. Användarna fick också ta fram en egen gränssnittprofil. Användarna har även att intervjuas med hjälp av ”Tänka-högt-protokoll” och detta skede efter ögonrörelsemätningarna. Här fick användare se sina egna ögonrörelser på en dator och kommentera detta. Till sist fick användarna svara på ett Webbformulär om hur de upplevde användbarheten i FriendlyReader Web. Sedan jämfördes båda gruppernas ögonrörelser för att se om det fanns några olik- och/eller likheter. Det viktigaste resultatet som kom fram i studien var att användarna tycker att FriendlyReader Web har ett enkelt gränssnitt och att gränssnittet fungera bra