The metabolic environment of the developing embryo: A multidisciplinary approach on oilseed rapeseed

Brassicaceae seeds consist of three genetically distinct structures: the embryo, endosperm and seed coat, all of which are involved in assimilate allocation during seed development. The complexity of their metabolic interrelations remains unresolved to date. In the present study, we apply state-of-the-art imaging and analytical approaches to assess the metabolic environment of the Brassica napus embryo. Nuclear magnetic resonance imaging (MRI) provided volumetric data on the living embryo and endosperm, revealing how the endosperm envelops the embryo, determining endosperm's priority in assimilate uptake from the seed coat during early development. MRI analysis showed higher levels of sugars in the peripheral endosperm facing the seed coat, but a lower sugar content within the central vacuole and the region surrounding the embryo. Feeding intact siliques with 13C-labeled sucrose allowed tracing of the post-phloem route of sucrose transfer within the seed at the heart stage of embryogenesis, by means of mass spectrometry imaging. Quantification of over 70 organic and inorganic compounds in the endosperm revealed shifts in their abundance over different stages of development, while sugars and potassium were the main determinants of osmolality throughout these stages. Our multidisciplinary approach allows access to the hidden aspects of endosperm metabolism, a task which remains unattainable for the small-seeded model plant Arabidopsis thaliana

Grundlagen und Anwendungen mehrelementiger pyroelektrischer Sensorsysteme (GAMPYS). Teilvorhaben: Sensortechnologien und Messtechnik pyroelektrischer Mehrelementsensoren Abschlussbericht

Pyroelectric single-element and multielement infrared sensors for application in pyrometry, gas analysis and thermography have been developed and tested using lithium tantalate LiTaO_3 as the pyroelectricum. LiTaO_3 wafers were prepared and their pyroelectric and dielectric properties were characterized for different chip layouts. Chip thickness of <5 #mu#m was achieved by ion beam etching. INDAB (induced absorption) layers obtained by on-chip layering of LiTaO_3 wafers and chips were structurated by the lift-off technique. A high-sensitivity single-element sensor, 4-channel and 2-channel multispectral sensors and a 128-element-line sensor were constructed and the sensor characteristics of these prototypes were measured as a function of ambient temperature and chopper frequency. (WEN)SIGLEAvailable from TIB Hannover: F97B596 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman