Stable heterologous expression of biologically active terpenoids in green plant cells

Plants biosynthesize a great diversity of biologically active small molecules of interest for fragrances, flavours, and pharmaceuticals. Among specialized metabolites, terpenoids represent the greatest molecular diversity. Many terpenoids are very complex, and total chemical synthesis often requires many steps and difficult chemical reactions, resulting in a low final yield or incorrect stereochemistry. Several drug candidates with terpene skeletons are difficult to obtain by chemical synthesis due to their large number of chiral centres. Thus, biological production remains the preferred method for industrial production for many of these compounds. However because these chemicals are often found in low abundance in the native plant, or are produced in plants which are difficult to cultivate, there is great interest in engineering increased production or expression of the biosynthetic pathways in heterologous hosts. Although there are many examples of successful engineering of microbes such as yeast or bacteria to produce these compounds, this often requires extensive changes to the host organism's metabolism. Optimization of plant gene expression, post-translational protein modifications, subcellular localization, and other factors often present challenges. To address the future demand for natural products used as drugs, new platforms are being established that are better suited for heterologous production of plant metabolites. Specifically, direct metabolic engineering of plants can provide effective heterologous expression for production of valuable plant-derived natural products. In this review, our primary focus is on small terpenoids and we discuss the benefits of plant expression platforms and provide several successful examples of stable production of small terpenoids in plants

最近の經濟學界

Direct assembly of multiple linear DNA fragments via homologous recombination, a phenomenon known as in vivo assembly or transformation associated recombination, is used in biotechnology to assemble DNA constructs ranging in size from a few kilobases to full synthetic microbial genomes. It has also enabled the complete replacement of eukaryotic chromosomes with heterologous DNA. The moss Physcomitrella patens, a non-vascular and spore producing land plant (Bryophyte), has a well-established capacity for homologous recombination. Here, we demonstrate the in vivo assembly of multiple DNA fragments in P. patens with three examples of effective genome editing: we (i) efficiently deleted a genomic locus for diterpenoid metabolism yielding a biosynthetic knockout, (ii) introduced a salt inducible promoter, and (iii) re-routed endogenous metabolism into the formation of amorphadiene, a precursor of high-value therapeutics. These proof-of-principle experiments pave the way for more complex and increasingly flexible approaches for large-scale metabolic engineering in plant biotechnology

Systematic and Phytochemical Studies of Quassia indica (Gaertn.) Nooteboom of Sarawak

Quassia indica (Gaertn.) Nooteboom is classified under the family Simaroubaceae. Species from Simaroubaceae are known to contain chemical compounds such as quassinoids due to its bitter taste. This project was mainly focused on the systematic studies of the morphological, wood anatomical, leaf epidennis structures of Q. indica and the preliminary analysis of the chemical compound present in the plant. The materials and methods include samples collection, preparation of wood samples, leaf samples, microscopic slides preparation, and microscopic observation to obtain detailed infonnation on anatomy structure of wood and leaf of the species. The vessel element of the wood cross section was diffuse and solitary porous with uniseriate parenchyma rays. The leaf epidennis cells of Q. indica were isodiametric and posses a mixture of tetracytic and polycytic stomata. Apart from this, phytochemical analyses were also conducted on Q. indica to examine the chemical component present. The analysis includes extraction of the leaves, stems and roots using hexane, ethyl acetate and methanol and phytochemical evaluation of extracts using HI Nuclear Magnetic Resonance (NMR) spectroscopy analyses. Types of proton detennined in this analysis were classified under alkane, methyl ketone, acetylenic, vinyl, allylic, aromatic, benzylic, ald~hyde, phenol, hydroxyl and methoxy. Further studies on the chemical compound of Q. indica should be undertaken to detennine the specific compound present in the species

Stable Production of the Antimalarial Drug Artemisinin in the Moss Physcomitrella patens

Malaria is a real and constant danger to nearly half of the world’s population of 7.4 billion people. In 2015, 212 million cases were reported along with 429,000 estimated deaths. The World Health Organization recommends artemisinin-based combinatorial therapies, and the artemisinin for this purpose is mainly isolated from the plant Artemisia annua. However, the plant supply of artemisinin is irregular, leading to fluctuation in prices. Here, we report the development of a simple, sustainable, and scalable production platform of artemisinin. The five genes involved in artemisinin biosynthesis were engineered into the moss Physcomitrella patens via direct in vivo assembly of multiple DNA fragments. In vivo biosynthesis of artemisinin was obtained without further modifications. A high initial production of 0.21 mg/g dry weight artemisinin was observed after only 3 days of cultivation. Our study shows that P. patens can be a sustainable and efficient production platform of artemisinin that without further modifications allow for industrial-scale production. A stable supply of artemisinin will lower the price of artemisinin-based treatments, hence become more affordable to the lower income communities most affected by malaria; an important step toward containment of this deadly disease threatening millions every year

Stable Production of the Antimalarial Drug Artemisinin in the Moss Physcomitrella patens

Malaria is a real and constant danger to nearly half of the world’s population of 7.4 billion people. In 2015, 212 million cases were reported along with 429,000 estimated deaths. The World Health Organization recommends artemisinin-based combinatorial therapies, and the artemisinin for this purpose is mainly isolated from the plant Artemisia annua. However, the plant supply of artemisinin is irregular, leading to fluctuation in prices. Here, we report the development of a simple, sustainable, and scalable production platform of artemisinin. The five genes involved in artemisinin biosynthesis were engineered into the moss Physcomitrella patens via direct in vivo assembly of multiple DNA fragments. In vivo biosynthesis of artemisinin was obtained without further modifications. A high initial production of 0.21 mg/g dry weight artemisinin was observed after only 3 days of cultivation. Our study shows that P. patens can be a sustainable and efficient production platform of artemisinin that without further modifications allow for industrial-scale production. A stable supply of artemisinin will lower the price of artemisinin-based treatments, hence become more affordable to the lower income communities most affected by malaria; an important step toward containment of this deadly disease threatening millions every year