Rabbit Anti-Human SPEG Polyclonal Antibody

A new targeting potentially intravenous conjugate Amphotericin B (AMB)-star poly(ethylene glycol) (sPEG) (M = 25,160) has been synthesized and characterized. It contains a beta-D-glucopyranoside molecular switch which is sensitive to beta-glucosidases (E. C. 3.2.1.21). The beta-glucosidase-catalyzed release of AMB from the polymeric carrier was proved in vitro by means of spectrophotometry and HPLC. (C) 2008 Elsevier Ltd. All rights reserved.

We report a formerly unknown mechanism in seeds which improves germination under relatively dry conditions. During seed development of several South American cacti, epidermal cells produce proteinaceous material that appears to pass through ectodesmata in the outer cell wall and which accumulates under the cuticle. Once moistened, this secretory layer readily absorbs water and distributes it over the seed surface. It thus improves water uptake and ensures germination with the minimum amount of available water, which may be advantageous in (semi-)arid regions. In experiments with seeds of Echinopsis thionantha (Speg.) Werd. and Gymnocalycium gibbosum (Haw.) Pfeiff. under water stress, intact seeds took up significantly more water and germinated better than seeds from which the hydrophilous layer had been artificially removed. (C) 1997 Annals of Botany Company.