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Background: It is yet unknown how maize plants respond to a partial root drying under conditions of a limited total water supply, and which adaptation mechanisms are triggered under these conditions. Aims: The aims of this study were to assess whether partial root drying results in distinguishable local and systemic physiological and metabolic drought responses, and whether compensatory water uptake and/or alteration of root architecture occurs under these conditions. Methods: Maize plants were grown in a split‐root system. When plants were 20 days old, the treatments 'well‐watered', 'local drought' and 'full drought' were established for a period of 10 days. Shoot length and gas exchange were measured non‐destructively, root exudates were collected using a filter system and biomass, relative water content, osmolality and proline content were determined destructively at final harvest. Results: Local drought triggered stress responses such as reduced biomass, shoot length, relative water content and increased osmolality. Maintained root growth was systemically achieved by hydraulic redistribution rather than by altering root architecture. Local and systemic osmolyte adjustments contributed to this hydraulic redistribution. Conclusions: Both local and systemic metabolic responses helped the plants to induce hydraulic redistribution, enhance water availability and in consequence plant water relations. This resulted in a surprisingly well‐maintained root growth even in the drought stressed root compartment. [ABSTRACT FROM AUTHOR]

Purpose: Mucilage plays crucial roles in root-soil interactions. Collection systems for maize (Zea mays L.) use primary and seminal roots of aeroponically-grown seedlings (CSA), or brace roots of soil-grown plants (CSB). While each method represents specific plant developmental stages, and root types growing in specific (micro-)environments, these factors are rarely considered. It is unclear whether mucilage exhibits distinct physico-chemical properties related to collection system-inherent factors. Methods: Mucilage of maize genotype B73 was collected from systems CSA and CSB. Chemical composition was assessed by pH, nutrient contents, neutral sugar composition, and polysaccharide polymer length. Viscosity, surface tension and contact angle represented physical properties. Results: The share of hexoses among total polysaccharides was 11% higher in CSB than in CSA, whereas pentoses were predominant in CSA, together with higher nutrient concentrations and pH values. Mannose was detected only in CSB, which also exhibited higher surface tension, viscosity and contact angle compared to CSA. Conclusions: Physico-chemical differences between the two mucilages are related to root type functions, environmental root growth conditions, and plant developmental state. Higher fractions of pentoses in CSA mucilage seem related to semi-sterile system conditions. Higher viscosity of CSB mucilage might reflect the need for enhanced water holding capacity of brace roots growing in drier conditions. A strong influence of environmental factors on mucilage properties even for a single genotype might play additional roles e.g. in the attraction of microbiomes. These aspects are relevant when assessing the role of mucilage in the rhizosphere, or when developing models of rhizosphere processes. [ABSTRACT FROM AUTHOR]

Strikingly, evolution shaped similar tubular structures at the mm to mm scale in roots of sessile plants and in small intestines of mobile mammals to ensure an efficient transfer of essential nutrients from 'dead matter' into biota. These structures, named root hairs (RHs) in plants and villi in mammals, numerously stretch into the environment, and extremely enlarge root and intestine surfaces. They are believed to forage for nutrients, and mediate their uptake. While the conceptional understanding of plant RH function in hydromineral nutrition seems clear, experimental evidence presented in textbooks is restricted to a very limited number of reference-nutrients. Here, we make an element-byelement journey through the periodic table and link individual nutrient availabilities to the development, structure/shape and function of RHs. Based on recent developments in molecular biology and the identification of mutants differing in number, length or other shape-related characteristics of RHs in various plant species, we present comprehensive advances in (i) the physiological role of RHs for the uptake of specific nutrients, (ii) the developmental and morphological responses of RHs to element availability and (iii) RHlocalized nutrient transport proteins. Our update identifies crucial roles of RHs for hydromineral nutrition, mostly under nutrient and/or water limiting conditions, and highlights the influence of certain mineral availabilities on early stages of RH development, suggesting that nutritional stimuli, as deficiencies in P, Mn or B, can even dominate over intrinsic developmental programs underlying RH differentiation. [ABSTRACT FROM AUTHOR]

Previous studies identify a relationship between education and anti-immigrant attitudes. There is, however, uncertainty regarding the underlying explanations linking education to attitudes. In this article, we examine whether a relationship exists between exposure to teaching about critical thinking as well as multiculturalism (measured as religions/cultures as well as xenophobia/racism), and anti-immigrant attitudes among adolescents. In addition, we examine whether teacher qualification matters for attitudes. The analysis is based on survey data collected from high school students in Sweden. The results show an association between exposure to teaching about critical thinking as well as multiculturalism (both indicators) and anti-immigrant attitudes among students, i.e. higher exposure is related to lower levels of anti-immigrant attitudes. However, we find that teaching about xenophobia/ racism affects attitudes, but not when simultaneously controlling for teaching about critical thinking and religions/cultures. In terms of teacher qualification, we find that students in schools with a high proportion of certified teachers tend to have lower levels of anti-immigrant attitudes. [ABSTRACT FROM AUTHOR]

In today's knowledge-based economy individual resources like human capital are one of the main driving forces to boost entrepreneurship. However, to date ethnic entrepreneurship research has paid much more attention to ethnic resources and ethnic markets, assuming that the use of group resources may compensate for a lack of educational achievement. Our article, therefore, analyzes the relevance and the interplay of both ethnic and individual resources and the resulting strategies of immigrant entrepreneurs in various markets. Based on official data and a survey we have conducted, our findings characterize contemporary ethnic entrepreneurship in Germany and its range of market strategies. It can be shown that only a minority of immigrant entrepreneurs exclusively rely on ethnic resources or on ethnic markets. That parallels trends in retail and food service activities which are becoming less important whereas the significance of knowledge-intensive services is increasing. This does not mean that highly educated immigrant entrepreneurs generally abstain from using ethnic resources. On the contrary, if better educated, they are better able to employ ethnic resources when exploiting distinct business opportunities. Overall, the combination of ethnic and human capital turns out to be a promising market strategy. [ABSTRACT FROM AUTHOR]