Mucilage Polysaccharide Composition and Exudation in Maize From Contrasting Climatic Regions

Mucilage, a gelatinous substance comprising mostly polysaccharides, is exuded by maize nodal and underground root tips. Although mucilage provides several benefits for rhizosphere functions, studies on the variation in mucilage amounts and its polysaccharide composition between genotypes are still lacking. In this study, eight maize (Zea mays L.) genotypes from different globally distributed agroecological zones were grown under identical abiotic conditions in a randomized field experiment. Mucilage exudation amount, neutral sugars and uronic acids were quantified. Galactose (∼39–42%), fucose (∼22–30%), mannose (∼11–14%), and arabinose (∼8–11%) were the major neutral sugars in nodal root mucilage. Xylose (∼1–4%), and glucose (∼1–4%) occurred only in minor proportions. Glucuronic acid (∼3–5%) was the only uronic acid detected. The polysaccharide composition differed significantly between maize genotypes. Mucilage exudation was 135 and 125% higher in the Indian (900 M Gold) and Kenyan (DH 02) genotypes than in the central European genotypes, respectively. Mucilage exudation was positively associated with the vapor pressure deficit of the genotypes’ agroecological zone. The results indicate that selection for environments with high vapor pressure deficit may favor higher mucilage exudation, possibly because mucilage can delay the onset of hydraulic failure during periods of high vapor pressure deficit. Genotypes from semi-arid climates might offer sources of genetic material for beneficial mucilage traits.

Investigation of Novel Te precursor (i-C3H7)2Te for MoTe2 Fabrication

ABSTRACTWe report the investigation on the properties of a novel Te precursor (i-C3H7)2Te and its effectiveness in fabricating MoTe2. The vapor pressure of the precursor was obtained by measuring the pressure as a function of its temperature in a sealed chamber. As a result it showed a high vapor pressure of 552.1 Pa at room temperature. The decomposition of the precursor was also investigated using DFT calculation. It was shown that the most likely reaction during the course of the decomposition of (i-C3H7)2Te is (i-C3H7)2Te → H2Te + 2 C3H7. The effectiveness of the precursor on the fabrication of MoTe2 was also investigated. Sputter-deposited MoO3 was tellurized in a quartz-tube furnace at the temperature up to 440°C. The resulting film showed that the 80% of the original MoO3 was tellurized to form MoTe2. It was also shown that further optimization of tellurization is required in order to prevent formation of metal Mo and elemental Te.