4 research outputs found
Physiological Responses to Salt Stress at the Seedling Stage in Wild (Oryza rufipogon Griff.) and Cultivated (Oryza sativa L.) Rice
Domesticated rice Oryza sativa L. is a major staple food worldwide, and the cereal most
sensitive to salinity. It originated from the wild ancestor Oryza rufipogon Griff., which was reported to
possess superior salinity tolerance. Here, we examined the morpho-physiological responses to salinity
stress (80 mM NaCl for 7 days) in seedlings of an O. rufipogon accession and two Italian O. sativa
genotypes, Baldo (mildly tolerant) and Vialone Nano (sensitive). Under salt treatment, O. rufipogon
showed the highest percentage of plants with no to moderate stress symptoms, displaying an
unchanged shoot/root biomass ratio, the highest Na+ accumulation in roots, the lowest root and
leaf Na+/K+ ratio, and highest leaf relative water content, leading to a better preservation of the
plant architecture, ion homeostasis, and water status. Moreover, O. rufipogon preserved the overall
leaf carbon to nitrogen balance and photosynthetic apparatus integrity. Conversely, Vialone Nano
showed the lowest percentage of plants surviving after treatment, and displayed a higher reduction
in the growth of shoots rather than roots, with leaves compromised in water and ionic balance,
negatively affecting the photosynthetic performance (lowest performance index by JIP-test) and
apparatus integrity. Baldo showed intermediate salt tolerance. Being O. rufipogon interfertile with
O. sativa, it resulted a good candidate for pre-breeding towards salt-tolerant lines
Photoluminescence Imaging for Buried Defects Detection in Silicon: Assessment and Use-Cases
International audienceSemiconducting piezoelectric materials have attracted considerable interest due to their central role in the emerging field of piezotronics, where the development of a piezo-potential in response to stress or strain can be used to tune the band structure of the semiconductor, and hence its electronic properties. This coupling between piezoelectricity and semiconducting properties can be readily exploited for force or pressure sensing using nanowires, where the geometry and unclamped nature of nanowires render them particularly sensitive to small forces. At the same time, piezoelectricity is known to manifest more strongly in nanowires of certain semiconductors. Here, we report the design and fabrication of highly sensitive piezotronic pressure sensors based on GaAs nanowire ensemble sandwiched between two electrodes in a back-to-back diode configuration. We analyse the current–voltage characteristics of these nanowire-based devices in response to mechanical loading in light of the corresponding changes to the device band structure. We observe a high piezotronic sensitivity to pressure, of ~7800 meV MPa −1 . We attribute this high sensitivity to the nanowires being fully depleted due to the lack of doping, as well as due to geometrical pressure focusing and current funnelling through polar interfaces