Potato plants (Solanum tuberosum ssp. tuberosum cv. Adel-fluid of the leaves and in the cell walls. Up to 60% more heid), multiplied in vitro, were cultivated in growth chambers diffusible pectin fragments were then found in the apoplast of younger leaves, as compared to the control supplied with an on nutrient solution at calcium regimes of 1000, 90, 60 or 30 mM Ca. An absolute Ca deficiency, particularly at the low optimum Ca level of 1000 mM. The amount of diffusible pectins accounted for 1 -2% of the total pectin content of Ca-supply levels of 30 and 60 mM Ca, manifested itself younger potato leaves. The size of the existing pectin frag-initially in the form of marginal necrosis in younger, but not in the youngest, leaves of the potato plants. Further symptoms ments varied depending on the Ca supply. Compared with an optimum Ca supply of 1000 mM, fewer monomers and up to 7 were rolling of the leaf lamina, browning of veins and roots, and finally necrosis also of the youngest leaves. Only in an times more diffusible pectin fragments with a degree of polyadvanced stage of Ca deficiency, the meristem of the shoots merization 9 -20 were present at the low Ca-supply level (30 mM). In addition, polygalacturonase activity in tissue ho-died. Ca-deficiency symptoms could be expected at a Ca content in the leaves of less than 5 mg Ca (g dry weight) − 1 . mogenates increased remarkably with Ca deficiency. Thus it appears that one major effect of Ca deficiency was a stimula-However, there was no close negative correlation between the tion of the activity of polygalacturonase, which could control extent of leaf damage and the total Ca content of the leaves. the breakdown of pectic polysaccharides in the cell wall. In order to obtain information about the Ca concentration in the apoplast fluid of the leaves, apoplastic washing fluid was Whether the release of potentially biologically active pectic fragments in cell walls might be involved in the occurrence of extracted by an infiltration-centrifugation technique. A low Ca supply reduced the Ca concentration both in the apoplast Ca-deficiency symptoms is discussed.
Increasing prices for wheat products and fertilizers, as well as reduced sulfur (S) contributions from the atmosphere, call for an improvement of product quality and agricultural management. To detect the impact of a time-dependent S fertilization, the quantitative protein composition and the baking quality of two different wheat cultivars, Batis and Turkis, were evaluated. The glutathione concentration in grains serves as a reliable marker of the need for added S fertilizer. The quantitation of gliadins and glutenin subunits by reversed-phase high-performance liquid chromatography confirmed that S-rich proteins significantly increased with S fertilization, whereas the S-poor proteins significantly decreased. Proteome analysis by means of high-resolution protein profiles detected 55 and 37 proteins from Batis and Turkis changed by late S fertilization. A microscale baking test using wholemeal flour was implemented for the evaluation of baking quality, and late S fertilization was found to improve the composition of gluten proteins and baking quality.
Production of whole-grain products can provide more variety in bakery products and might impact positive health effects due to fermentable soluble fibers. To assess technological quality, micro-scale methods using 10 g of white flour are usually carried out, in particular if amount of material or additives is limited. Using wholemeal flour for micro-scale testing might enhance use efficiency of raw material. Up to date, there is no information, whether micro-scale testing of wholemeal flour provides the same information on techno-functionality as classical methods. Two wheat varieties with the same protein concentration but different bread-making performance were used to analyze this aspect. Micro-scale baking test was optimized for wholemeal flour concerning dough consistency and fermentation time. Wholemeal flour reduced loaf volume, but optimization was successful. Although all processing steps of wholemeal baking test were adapted, differences in loaf volume between the two varieties were only present with white flour. Coarse particles in wholemeal flour may be responsible for reduced gas retention. Decreasing particle size of bran material might reduce adverse effects on loaf volume. A micro-scale baking test using wholemeal flour would have several advantages after correct implementation: lower price, less time and material required, direct measurement of quality aspects.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.