Quantitative and functional post-translational modification proteomics reveals that TREPH1 plays a role in plant thigmomorphogenesis

Plants can sense both intracellular and extracellular mechanical forces and can respond through morphological changes. The signaling components responsible for mechanotransduction of the touch response are largely unknown. Here, we performed a high-throughput SILIA (stable isotope labeling in Arabidopsis)-based quantitative phosphoproteomics analysis to profile changes in protein phosphorylation resulting from 40 seconds of force stimulation in Arabidopsis thaliana. Of the 24 touch-responsive phosphopeptides identified, many were derived from kinases, phosphatases, cytoskeleton proteins, membrane proteins and ion transporters. TOUCH-REGULATED PHOSPHOPROTEIN1 (TREPH1) and MAP KINASE KINASE 2 (MKK2) and/or MKK1 became rapidly phosphorylated in touch-stimulated plants. Both TREPH1 and MKK2 are required for touch-induced delayed flowering, a major component of thigmomorphogenesis. The treph1-1 and mkk2 mutants also exhibited defects in touch-inducible gene expression. A non-phosphorylatable site-specific isoform of TREPH1 (S625A) failed to restore touch-induced flowering delay of treph1-1, indicating the necessity of S625 for TREPH1 function and providing evidence consistent with the possible functional relevance of the touch-regulated TREPH1 phosphorylation. Bioinformatic analysis and biochemical subcellular fractionation of TREPH1 protein indicate that it is a soluble protein. Altogether, these findings identify new protein players in Arabidopsis thigmomorphogenesis regulation, suggesting that protein phosphorylation may play a critical role in plant force responses

Multivariate NIR studies of seed-water interaction in Scots Pine Seeds (Pinus sylvestris L.)

This thesis describes seed-water interaction using near infrared (NIR) spectroscopy, multivariate regression models and Scots pine seeds. The presented research covers classification of seed viability, prediction of seed moisture content, selection of NIR wavelengths and interpretation of seed-water interaction modelled and analysed by principal component analysis, ordinary least squares (OLS), partial least squares (PLS), bi-orthogonal least squares (BPLS) and genetic algorithms. The potential of using multivariate NIR calibration models for seed classification was demonstrated using filled viable and non-viable seeds that could be separated with an accuracy of 98-99%. It was also shown that multivariate NIR calibration models gave low errors (0.7% and 1.9%) in prediction of seed moisture content for bulk seed and single seeds, respectively, using either NIR reflectance or transmittance spectroscopy. Genetic algorithms selected three to eight wavelength bands in the NIR region and these narrow bands gave about the same prediction of seed moisture content (0.6% and 1.7%) as using the whole NIR interval in the PLS regression models. The selected regions were simulated as NIR filters in OLS regression resulting in predictions of the same quality (0.7 % and 2.1%). This finding opens possibilities to apply NIR sensors in fast and simple spectrometers for the determination of seed moisture content. Near infrared (NIR) radiation interacts with overtones of vibrating bonds in polar molecules. The resulting spectra contain chemical and physical information. This offers good possibilities to measure seed-water interactions, but also to interpret processes within seeds. It is shown that seed-water interaction involves both transitions and changes mainly in covalent bonds of O-H, C-H, C=O and N-H emanating from ongoing physiological processes like seed respiration and protein metabolism. I propose that BPLS analysis that has orthonormal loadings and orthogonal scores giving the same predictions as using conventional PLS regression, should be used as a standard to harmonise the interpretation of NIR spectra

USSR Space Life Sciences Digest, issue 6

This is the sixth issue of NASA's USSR Space Life Sciences Digest. It contains abstracts of 54 papers recently published in Russian language periodicals and bound collections and of 10 new Soviet monographs. Selected abstracts are illustrated with figures and tables from the original. Additional features include a table of Soviet EVAs and information about English translations of Soviet materials available to readers. The topics covered in this issue have been identified as relevant to 26 areas of aerospace medicine and space biology. These areas are adaptation, biospherics, body fluids, botany, cardiovascular and respiratory systems, developmental biology, endocrinology, enzymology, exobiology, genetics, habitability and environment effects, health and medical treatment, hematology, human performance, immunology, life support systems, mathematical modeling, metabolism., microbiology, morphology and cytology, musculoskeletal system, neurophysiology, nutrition, perception, personnel selection, psychology, radiobiology, reproductive biology, and space medicine

Developing cropping systems for the ancient grain chia (Salvia hispanica L.) in two contrasting environments in Egypt and Germany

In den letzten Jahren entwickelte sich um Chiasamen (Salvia hispanica L.) ein regelrechter Hype. Als sogenanntes Superfood für die menschliche Ernährung, vor allem für Veganer und Vegetarier, wurden Chiasamen wiederentdeckt. Daher gibt es immer mehr Lebensmittelprodukte mit Chiasamen. Diese Samen sind vorteilhaft, weil sie frei von Gluten sind, ein ausgewogenes Verhältnis von Makronährstoffen aufweisen und einen hohen Anteil an Omega-3-Fettsäuren, Mikronährstoffen, Antioxidantien und Ballaststoffen enthalten. Chia ist ursprünglich an Kurztagbedingungen angepasst und in tropischen und subtropischen Gebieten verbreitet. Dennoch kommt es mit Bedingungen wie Wasserstress zurecht und kann daher auch in trockenen Regionen angebaut werden. Ägypten wurde als wasserknappes Land eingestuft. Chia kann aufgrund seiner Trockenstresstoleranz dazu beitragen die knappe Ressource Wasser in Ägypten einzusparen und bietet gleichzeitig Exportmöglichkeiten. Im Gegenzug kann dadurch z.B. Weizen mit einem höheren Wasserbedarf importiert werden. Der Klimawandel und die damit verbundene mangelnde Wasser- und Ernährungssicherheit stellen eine der weltweit größten Herausforderungen in ariden und semiariden Regionen dar und gefährden in Zukunft nicht nur die landwirtschaftliche Produktion, sondern auch die nachhaltige Entwicklung. Auf der anderen Seite, erfordert eine steigende Bevölkerung einerseits eine Steigerung der Nahrungsmittelproduktion, andererseits auch den Wandel zu einer umweltverträglichen und nachhaltigen Landwirtschaft. Chia könnte eine wirtschaftliche Alternative zu den herkömmlichen Feldfrüchten darstellen und so die Diversifizierung und Stabilisierung der lokalen Agrarwirtschaft unterstützen. Es fehlt jedoch die Erfahrung zum Anbau von Chia in neuen Regionen. Die Mehrheit der bisherigen Studien zu Chia legte den Schwerpunkt auf Qualitätseigenschaften der Samen. Das traditionelle Anbausystem von Chia wurde bislang nicht modernisiert und Informationen über den Einsatz von Düngemitteln, Pestiziden und verbesserten Sorten sind nur vereinzelt zu finden, welches Gründe für eine geringe Produktivität sind. Um die gestiegene Nachfrage an Chiasamen zu decken, werden neue Erzeugerländer hinzukommen müssen, für die Anbaukonzepte fehlen. Im Zeitraum von 2015 bis 2017 wurden Feldversuche an der Versuchsstation Ihinger Hof der Universität Hohenheim im Südwesten Deutschlands und in Ägypten von 2015 bis 2016 an der 50 km nordöstlich von Kairo gelegenen Versuchsstation von SEKEM durchgeführt. Die vorliegende Dissertation basiert auf einem von der Anton-&-Petra-Ehrmann-Stiftung geförderten Projekt, das sich auf die Graduiertenschule Wasser-Menschen-Landwirtschaft (WPA) an der Universität Hohenheim stützt und sich mit zentralen Fragen zum Thema Wasser und wasserbezogenen Herausforderungen der heutigen Gesellschaft befasst. Abschließend ist festzuhalten, dass die Ergebnisse dieser Arbeit neue zentrale Informationen über den Anbau von Chia in zwei unterschiedlichen Regionen (einschließlich einer Wüstenregion) außerhalb des ursprünglichen Verbreitungsgebietes liefern. Die vorliegende Dissertation stellt einen ersten und vielversprechenden Ansatz zur Entwicklung eines Blattflächenmodells für Chia dar. Darüber hinaus kombiniert die Arbeit experimentelle Ansätze in Feldversuchen mit Pflanzenwachstumsmodellen, um die Anbaumethoden von Chia in neuen Regionen zu unterstützen und zu optimieren. Dafür wurde erstmals das CROPGRO-Modell für Chia angepasst, um Ertrag und Wachstumsparameter abzubilden. Darüber hinaus trug diese Arbeit dazu bei, den allgemeinen Quellcode des Modells zu verbessern, um das Wachstum sehr kleiner Samen zu simulieren. Die Anpassung an andere Salvias sollte mit diesem entwickelten Modell ebenfalls wesentlich einfacher sein. Zukünftige Modellverbesserungen und die Integration eines Tools, das ebenfalls die Kornqualität simulieren kann, könnten das Pflanzenwachstumsmodel für Chia weiter verbessern.Chia (Salvia hispanica L.) seeds have been revived as functional superfood for human nourishment especially for vegan and vegetarian diets and are becoming increasingly widespread and present in new food products in Europe. The seeds are beneficial because of being gluten-free, containing antioxidants and a high concentration of α-linolenic acid, and having a high content of dietary fiber and high-quality protein. Chia is originally adapted to short-day conditions and grows naturally in tropical and subtropical environments. Nevertheless, it can survive under water stress and could, therefore, be cultivated in arid regions. Egypt has been classified as a water-scarce state. Due to its drought tolerance, chia might contribute to saving the scarce source water in Egypt and offer the chance to export these high value seeds, generating foreign exchange for reimporting e.g. wheat characterized by a higher water demand. Worldwide, the biggest problems and key challenges under climate change (CC) are water and food security in arid and semiarid regions. In the future, CC and water scarcity will significantly threaten agriculture and sustainable development. A rising population requires on the one hand an increase in food grain production, but also a change toward environmentally sound sustainable agriculture. Chia has been suggested as a favorably economic alternative for common field crops sustaining diversification and stabilization of the local agricultural economy. However, broad experience in growing chia in new environments is missing. The agronomic management has not been improved from formerly small-scale production systems. Most of the previous studies focused on seed characteristics. Information on fertilization, plant protection, and improved varieties is scarce, which are reasons for its low productivity in the countries of origin. Field experiments were conducted at the experimental station Ihinger Hof of the University of Hohenheim in southwestern Germany from 2015 to 2017 and in Egypt during the cropping season 2015 to 2016 at SEKEMs experimental station located 50 km Northeast of Cairo. The present doctoral thesis was based on a project embedded in the graduate school Water-People-Agriculture (WPA) at the University of Hohenheim funded by the Anton-&-Petra-Ehrmann foundation that focuses on key water issues and water related challenges of todays society. On a final note, the main results of this thesis provide further information and expanded knowledge on chia cultivation in two contrasting environments (including a desert region) out of its center of origin. Overall, the current doctoral thesis presents a combined approach of experimental field research and crop modeling to support the optimization of farming practices of chia in new environments. A universal and nondestructive LA estimation model for chia was developed. Further, the CROPGRO model was adapted for chia to provide a preliminary model for a realistic simulation of crop growth variables. The approaches presented in this thesis may contribute to testing new environments for chia cultivation and to improving its production. Moreover, this study helped to develop further general model source codes to simulate the growth of tiny seeds. The adaptation to other Salvias should be much easier with this developed model. Future research requirements and issues requiring model improvement such as N-response and the development of code relationships that can simulate parameters of seed quality could improve the plant growth model for chia

Modeling seed germination and seedling emergence in winterfat (krascheninnikovia lanata (pursh) A.D.J. Meeuse & Smit) : physiological mechanisms and ecological relevance

Winterfat (Krascheninnikovia lanata) a native shrub has superior forage quality for livestock and wildlife, and is important in the structure and the function of the Northern Mixed Prairie of North America. Seedbeds in the Northern Mixed Prairie are characterized by high fluctuations in temperature and soil water, especially at the soil surface during the spring under unpredictable weather conditions. High seedling mortality is a major limitation for establishing winterfat from direct seeding. Objectives of this study were to: 1) quantify germination responses to temperature and water potential; 2) predict seed germination and seedling emergence using constructed threshold models; and 3) investigate physiological mechanisms and the ecological relevance of model parameters. The constructed thermal and hydrothermal time models predicted germination time in most controlled temperature and water potential regimes with the modification of model assumptions in winterfat. For the first time, it was proved that winterfat seeds have a subzero base temperatures (Tb) for germination, achieving 43 to 67% germination at – 3oC. The estimated Tb was lower in the large seeds (-4.5oC) than in the small seeds (-3.5oC) and the difference between seed collections was also about 1oC. Lower Tb favors large seeds to accumulate more thermal time at a given temperature, especially in early spring or fall when temperatures are low. Basic assumptions of hydrothermal time model, such as the constancy of model parameters, are invalid in winterfat. Model parameters varied with water potential, temperature and seed size within a seed collection. The predictability of constructed models is acceptable for seedling emergence only at optimal conditions in the field. Adverse seedbed conditions such as high soil temperatures (> 15oC) and limited soil water (< -0.5 MPa) reduced predictability of seedling emergence with the hydrothermal time model. Pre- and post-germination events that affect seed deterioration, seedling mortality and seedling elongation may reduce the predictability of the hydrothermal time model. Small seeds required approximately twice as long as large seeds to reach 50% germination at -1 to -3oC. Greater cold tolerance in large seeds was correlated with greater membrane integrity, less cold imbibition damage, higher contents of soluble cryoprotective sugars, such as glucose, raffinose and sucrose during germination at low temperature. These sugars prevent from dysfunctions of cell membrane and enzymes at freezing temperatures

Efficacy of non-synthetic seed treatments against anthracnose (Colletotrichum lupini) in white lupin

White lupin (Lupinus albus) is an interesting crop for use as food, feed, forage or cover crop. However, its cultivation is currently limited because of its high susceptibility to the seed-borne pathogen Colletotrichum lupini, causal agent of lupin anthracnose. Twenty-eight seed treatments were studied here for their efficacy against lupin anthracnose, consisting of 4 hot water, 5 steam, 4 dry heat, 5 electron, 2 plant-based and 2 microbial treatments, as well as 6 controls. Experiments were divided into a germination assay and a pot-based disease assessment experiment. Treatment effects were studied by visual assessments of plants, culture-based incubation of plant tissue and quantitative polymerase chain reaction (qPCR)-based detection of Colletotrichum spp. in plants. Only the sodium hypochlorite control significantly impaired germination rate, normal germination rate and early vigour of seedlings. Culture-based incubation of epicotyl samples from 1.5-week old seedlings revealed significant treatment effects on the overall seed microbiome. No significant treatment effects were observed for plant vitality scores, percentage of diseased leaves and plant biomass at harvest. Colletotrichum spp. was detected in epicotyl samples of 1.5-week old seedlings and in shoot samples of 7.5-week old plants, but no significant treatment effects were observed. Absence of treatment effects could be due to insufficient power of the tested treatments, or to insufficient pathogen levels in the plants. No characteristic anthracnose symptoms were observed, and it is possible that the initial seed inoculum level was too low to lead to sufficient disease pressure in the plants. Nevertheless, the steam treatments significantly reduced the overall seed microbiome, and no Colletotrichum spp. was detected in seedlings or grown shoots, indicating a potential efficacy of the steam treatments against lupin anthracnose. The treatments dry heat 75°C/5h, electron at penetration depth 3 and intensity 3, and thyme oil also showed slight indications of efficacy against lupin anthracnose

ASSESSING BEST MANAGEMENT PRACTICES FOR IMPROVING SWITCHGRASS ESTABLISHMENT AND PRODUCTION

Switchgrass (Panicum virgatum L.) is a C4-grass indigenous to North America being considered as the “model” energy crop. Switchgrass is difficult to establish and first-year stand failure often challenge the large scale production of switchgrass. Reliable establishment methods and effective weed management practices to produce a harvestable biomass in the establishment year are required. Also, to maximize the economic viability of switchgrass production, appropriate nutrient management and harvests are needed. Thus, we conducted researches to improve switchgrass establishment and production. These studies ranged from finding the most promising switchgrass variety to adjusting switchgrass seeding rate, determine the most appropriate seeding date, seeding methods, weed management, nitrogen application, and harvest management. Currently Cave-in-Rock is a highly suggested upland variety for northern region of United States. Results of our variety trials both at establishment and production level indicated that Carthage and Shawnee could also be considered as promising varieties in northern regions of United States. In a four-year study, Carthage consistently produced higher biomass yield compared with other varieties. A vigor test trial was suggested for adjusting switchgrass seeding rate and we found significant differences between the required seeding rate for producing acceptable first-year biomass in fertile soils and marginal soils. While approximately 7 kg ha-1 seeding rate might be sufficient for fertile soils, 14 kg ha-1 might be required to produce enough established seedling for the same biomass production in a marginal soil. An early planting of switchgrass was not as effective as a late planting in weed suppression but plants were more advanced morphologically thus, produced acceptable biomass yield with root system which ensures successful second-year production. Among cover crops, oat outperformed others (Fallow and Rye) with both suppressing weeds and improving switchgrass establishment. Results suggested drastic differences between no-till planting and seeding with cultipacker seeder where no-till planting into oat produced significantly higher biomass yield compared with cultipacker seeder. A firm seedbed is also another desirable method of planting where significantly improved switchgrass establishment and production was observed with 2 times rolling/cultipacking after seeding. Our findings indicated that application of herbicides is strongly required in the establishment year where a Broad Spectrum application of atrazine, quinclorac, 2,4-D, and dicamba improved switchgrass establishment through effective control of weeds. We found a late-fall harvest could improve switchgrass quality for combustion (less moisture, ash, and nutrient content) without yield reduction for many years. When switchgrass was harvested in late-fall, no response to N application was found. Overall, it is proposed that a no-till planting of switchgrass into oat cover crop with herbicide application planted in early-June could provide a successful stand and later, a late-fall harvest without any N application could maintain crop productivity with acceptable biomass yield and quality for several years

Modern Seed Technology

Satisfying the increasing number of consumer demands for high-quality seeds with enhanced performance is one of the most imperative challenges of modern agriculture. In this view, it is essential to remember that the seed quality of crops does not improve

USSR Space Life Sciences Digest, issue 29

This is the twenty-ninth issue of NASA's Space Life Sciences Digest. It is a double issue covering two issues of the Soviet Space Biology and Aerospace Medicine Journal. Issue 29 contains abstracts of 60 journal papers or book chapters published in Russian and of three Soviet monographs. Selected abstracts are illustrated with figures and tables from the original. A review of a book on environmental hygiene and a list of papers presented at a Soviet conference on space biology and medicine are also included. The materials in this issue were identified as relevant to 28 areas of space biology and medicine. The areas are: adaptation, aviation medicine, biological rhythms, body fluids, botany, cardiovascular and respiratory systems, developmental biology, digestive system, endocrinology, equipment and instrumentation, genetics, habitability and environment effects, hematology, human performance, immunology, life support systems, mathematical modeling, metabolism, musculoskeletal system, neurophysiology, nutrition, personnel selection, psychology, radiobiology, reproductive system, space biology and medicine, and the economics of space flight