TY - THES T1 - Translocation and storage of chloride in chlorine-stressed maize (Zea mays L.) A1 - Zhang,Xudong Y1 - 2021/02/17 N2 - Maize (Zea mays L.) is a moderately salt-sensitive species, its sensitivity to NaCl being mainly associated with the accretion of toxic sodium in shoots for example leading to the sodium-induced damage of leaf chloroplasts. However, less attention has been paid to the effects of chloride (Cl-). The work described in this dissertation therefore aims at elucidating the physiological adaptations of maize plants to Cl- salinity. It involves four research questions: 1) how do sensitive maize plants respond to Cl- salinity with regard to crop yield and plant performance; 2) how are the translocation and tissue storage patterns of Cl- correlated with tolerance to Cl- salinity; 3) how do osmotic stress and Cl- stress impact biomass, chlorophyll content, and nitrate reductase activity (NRA); 4) does sensitivity to Cl- salinity differ between maize and faba bean plants? Soil pot experiments and hydroponic culture experiments in the greenhouse have shown that maize is able to withstand Cl- salinity by being a shoot excluder. The relevant genotypic difference is believed to be based on its ability to undertake Cl- root-to-shoot translocation. The resistance mechanism of the genotype ES-metronom, which is a more Cl- -tolerant variety, has been attributed to its more efficient shoot exclusion of Cl-,whereas that of the genotype P8589, which is a more Cl- -sensitive variety has been ascribed to the preferable sequestration of Cl- away from the young photosynthetic tissues, such as into old leaf blades, and Cl- movement in roots possibly to achieve Cl- dilution. In the mildly tolerant genotype LG30215, osmotic stress does not interfere with NRA but slows down mass flow, which probably reduces NO3- transport to leaf tissues, whereas excess Cl- indirectly inhibits NRA through the antagonistic limitation of NO3- uptake. In comparison with maize, faba bean plants are more sensitive to Cl- salinity rather than to sodium toxicity. KW - Mais KW - Biomasse KW - Photosynthese CY - Hohenheim PB - Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim AD - Garbenstr. 15, 70593 Stuttgart UR - http://opus.uni-hohenheim.de/volltexte/2021/1843 ER -