Proteomics, the systematic analysis of (differentially) expressed proteins, is a tool for the identification of proteins involved in cellular processes. Proteomics has already been used for many different applications in plant sciences, including the study of proteins of biosynthetic pathways leading to secondary metabolites. In secondary metabolism, many enzymes are involved, often working in close collaboration to catalyse cascades of reactions. Besides the enzymes, transport and regulatory proteins are also involved, which makes the proteome an essential topic for studying metabolic pathways. Proteomics technology is based on high-throughput techniques for the separation and identification of proteins, allowing an integral study of many proteins at the same time. For the separation of protein mixtures the most powerful technique available is two-dimensional polyacrylamide gel electrophoresis: after separation, proteins can be subsequently identified by mass spectrometry (MS). The increasing amount of genome sequence data has to be followed by deciphering the function of the genes and proteins. Studying differential expression by proteomics is a complementary tool for functional analysis. In this review practical aspects and applications of proteomics in plant sciences, with particular emphasis on secondary metabolism, are discussed. Copyright © 2000 John Wiley & Sons, Ltd.

Proteomics in plant biotechnology and secondary metabolism research

Catharanthus roseus is an important drug. Traditionally, different parts of it used in the treatments of various diseases (viz. diabetes, menstrual regulators, hypertension, cancer and antigalactagogue etc.), in numbers of countries (Australia, Brazil, China, Cook Island, Dominica, England, Europe, France, French Guina, India, Jamaica, Kenya, Mexico, Mozambique, North Vietnam, Pakistan, Peru, Philippines, South Africa, South Vietnam, Taiwan, Thailand, USA, Venda, Vietnam, West Indies etc.). Moreover, more than 130 alkaloids have been isolated from different parts; amongst which two important alkaloids (Vinblastine and Vincristine used in cancer treatment) present in very low concentrations. Keeping these views; researcher continuously using different approaches to enhance the level of important alkaloid to meet the required demand. Thus, in present communication various in vitro biotechnological and biochemical approaches (viz. effect of media composition, plant growth regulators, pH of the culture medium, temperature, light, aeration, elicitors, mutagenesis, high cell density culture, selection of superior cell lines, bioreactor and immobilization methods, hairy root culture, somatic embryogenesis, biosynthesis of alkaloids, metabolic and genetic engineering in alkaloids biosynthesis, coupling method for alkaloids biosynthesis, cellular compartmentation etc.) have been used worldwide; which directly concerning with the in-vitro micropropagation and the enhancement of important secondary metabolites present in different parts of Catharanthus and being used in the treatment of various diseases.

Catharanthus roseus (l.) g. don. an important drug: its applications and production

Cytokinins and ethylene stimulate indole alkaloid accumulation in cell suspension cultures of Catharanthus roseus by two distinct mechanisms

Catharanthus roseus L. is a potent medicinal plant belonging to Apocynaceae family. In a number of countries, different parts of it are traditionally used in the treatment of various diseases, e.g. diabetes, menstrual irregulations, hypertension, cancer, etc. The high added-value of this plant is because of its enormous pharmaceutical features, which are because of its more than 130 terpenoid indole alkaloids (TIAs), some of which exhibiting imperative pharmacological activities. The most striking biological activity investigated is the antitumour effect of dimeric alkaloids such as that of anhydrovinblastine, vinblastine and vincristine, which are under study either in preclinical phase or are being used presently. The great pharmacological importance of these indole alkaloids contrasts with their small amounts in the plant, making their extraction a very expensive process. To overcome this problem, researches have looked for alternative sources and have been trying the strategies to produce them in higher amounts. Using biotechnological approaches, intensive research on the biosynthesis of TIAs and on the regulation of their biochemical pathways has been developed with the aim to increase the production of these high added-value compounds. This chapter is focused on the pharmaceutical application of the antitumour alkaloids and on the various strategies which improve the production of these alkaloids; it also analyses the beneficial effects that these compounds exert on human health.

Vincristine and Vinblastine Anticancer Catharanthus Alkaloids: Pharmacological Applications and Strategies for Yield Improvement

The effect of salt stress on the polypeptide levels in roots of two wheat (Triticum durum) cultivars with different sensitivity to NaCl (cv. Ben Bachir, sensitive; cv. Chili, tolerant), was examined by two-dimensional polyacrylamide gel electrophoresis. Blue-stained gels were analyzed by visual inspection to identify changes that resulted when seedlings were grown in the presence of 200 mM NaCl for four days. Although the protein patterns for control and salt-stressed seedlings were qualitatively similar, the net synthesis of a 26 kDa polypeptide was significantly changed. This observation was mainly noticeable in the more tolerant cultivar. With the intention of identifying its function, the NH2-terminal of this polypeptide was sequenced. A 20 amino acid sequence was obtained and compared to sequences available in different databases. Possible roles of this polypeptide, depending on the homologies of its amino acid sequence with known proteins, in salinity tolerance are discussed.

Analysis by two-dimensional electrophoresis of the effect of salt stress on the polypeptide patterns in roots of a salt-tolerant and a salt-sensitive cultivar of wheat.

Mohammed Filali

Papers

Differential protein accumulation in zeatin-and 2,4-D-treated cells of Catharanthus roseus. Correlation with indole alkaloid biosynthesis