A rubber biosynthesis stimulator protein (RBSP)from the C-serum of Hevea brasiliensis latex was purified and characterised. This proteinaceous factor stimulates the incorporation of isopentenyl diphosphate into rubber and thereby enhances the rate of rubber biosynthesis. The heat stable RBSP is shown to have a molecular weight of 13 068 Da by mass spectroscopy. Amino acid sequence of peptide fr...

Superoxide dismutases (SODs; superoxide: superoxide oxidoreductase, EC 1.15.1.1) play a key role in protection against oxygen radicals, and SOD gene expression is highly induced during environmental stress. To determine the conditions of SOD induction, the promoter of the cytosolic copper/zinc SOD (Cu/ZnSODcyt) gene was isolated in Nicotiana plumbaginifolia and fused to the beta-glucuronidase r...

Suspension cultures of carrot (Daucus carota, line C1), tobacco (Nicotiana tabacum, line TX1), and Nicotiana plumbaginifolia (line NP) were frozen under controlled conditions with trehalose as the sole cryoprotectant. Maximal post-thaw viability (71-74%), measured by phenosafranin dye exclusion, was obtained with the C1 cells following a 24hour pretreatment with 5 or 10% trehalose and with 40% ...

ENETIC tumors in Nicotiana species hybrids have been reported by several Ginvestigators. These tumors are formed in certain specific hybrid combinations on stems, roots, and occasionally on leaves of all or part of the F, progeny. Since the discovery by KOSTOFF (1930) of nine interspecific tumorous hybrids, almost 20 additional hybrid combinations have been reported in which the entire progeny ...

We report the presence of an ATP-dependent proteolytic activity in spinach (Spinacia oleracea) leaf mitochondria. The proteolysis was observed as degradation of newly imported precursor protein. The precursor studied was that of the ATP synthase F1 beta subunit of Nicotiana plumbaginifolia, transcribed and translated in vitro. Degradation of pre-F1 beta was observed during kinetic studies of im...

Expression of the malate synthase (MS) gene is activated in cotyledons of cucumber seedlings during postgerminative growth and then repressed as the cotyledons become photosynthetic. MS gene expression is subsequently reactivated in the cotyledons as they senesce a few weeks later. In situ hybridization revealed that MS RNA is distributed throughout the organ during postgerminative growth and s...