Madagascar periwinkle [Catharanthus roseus (L.) G Don] is a pantropical plant of horticultural value that produces the powerful anticancer drugs vinblastine and vincristine that are derived from the dimerization of the monoterpenoid indole alkaloids (MIAs), vindoline and catharanthine. The present study describes the genetic engineering and expression of the terminal step of vindoline biosynthesis, deacetylvindoline-4-O-acetyltransferase (DAT) in Catharanthus roseus hairy root cultures. Biochemical analyses showed that several hairy root lines expressed high levels of DAT enzyme activity compared to control hairy root cultures expressing beta-gulucuronidase activity (GUS) activity. Metabolite analysis using high performance liquid chromotagraphy established that hairy root extracts had an altered alkaloid profile with respect to horhammericine accumulation in DAT expressing lines in comparison to control lines. Further analyses of one hairy root culture expressing high DAT activity suggested that DAT expression and accumulation of horhammericine (9) were related. It is concluded that expression of DAT in hairy roots altered their MIA profile and suggests that further expression of vindoline pathway genes could lead to significant changes in alkaloid profiles. Evidence is provided that horhammericine (9) accumulates via a DAT interaction with the root specific minovincinine-19-O-acetyltransferase (MAT) that inhibits the MAT mediated conversion of hammericine (9) into 19-O-acetyl-horhammericine (12). (c) 2007 Elsevier Ltd. All rights reserved.

Plant cell suspension cultures are reliable year-round sources of enzymes involved in secondary metabolite biosynthesis. Numerous studies have used V. vinifera cell suspension cultures as an experimental system for studying these processes, while those from Concord grape (V. labrusca L.) have been poorly exploited. V. vinifera cell suspension cultures have been shown to grow well with casein hydrolysate (CH), which is a good source of reduced nitrogen in many tissue culture systems. The present report shows that V. labrusca cell suspension cultures, in contrast to those of V. vinifera, could only be established in the absence of CH as a source of reduced nitrogen. CH contains 20 amino acids, among which, the single amino acid l-alanine activates a programmed cell death response in V. labrusca cells, as determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay and propidium iodide nuclei staining. Programmed cell death was accompanied by the coordinated activation of phenylalanine ammonia lyase (PAL), cinnamic acid 4-hydroxylase (C4H), and stilbene synthase (STS) gene expression, as well as by the accumulation of stilbenes and other phenolic compounds.

The Madagascar periwinkle [Catharanthus roseus (L.) G. Don] is a commercially important horticultural flower species and is the only source of the monoterpenoid indole alkaloids (MIAs), vinblastine and vincristine, key pharmaceutical compounds used to combat a number of different cancers. The present study uses high performance liquid chromatography for metabolic profiling of the MIAs extracted from seedlings and young leaves of 50 different flowering cultivars of C. roseus to show that, except for a single low vindoline cultivar (Vinca Mediterranean DP Orchid), they accumulate similar levels of MIAs. Further enzymatic studies with extracts from young leaves and from developing seedlings show that the low vindoline cultivar has a 10-fold lower tabersonine-16-hydroxylase activity than those of C. roseus cv. Little Delicata. It is concluded that rapid metabolic and more selective enzymatic profiling of Catharanthus mutants could be useful for the identification of a range of altered MIA biosynthesis lines.

Summary Meristematic clusters were induced from daylily scape explants (pedicel-scape junction) in the presence of the growth retardant Paclobutrazol on semisolid agar medium. Liquid shake culture was used to proliferate meristematic clusters. Highly efficient regeneration of adventitious shoots occurred on clusters after subculture on a 0.8% agar strength semisolid medium with the addition of activated charcoal. Paclobutrazol and sucrose levels in the media were found to significantly affect starch accumulation, growth value, and dry weight percentage of liquid-cultured meristematic clusters. The use of liquid shake cultures for mass proliferation of meristematic clusters followed by regeneration of adventitious shoots on semisolid agar culture could be an efficient system for large-scale micropropagation of daylily.

The relation ship between thermal conductivity and w ater content of tobacco is presented in this paper. The accuracy of the recommen ded formula is checked by experimental data. The calculated results agree very w ell with the experimental data. For leaf tobacco stack, the absolute average dev iation is 1.75%,and the arithmetic average deviation is 0.15%, while for cut tobacco as compared with 2.36% and 0.25%, respectively, for cut tobacco. The for mula can be also used to calculate other porous material.