Metabolic engineering for enhanced terpenoid production: Leveraging new horizons with an old technique.

Terpenoids are a vast class of plant specialized metabolites (PSMs) manufactured by plants and are involved in their interactions with environment. In addition, they add health benefits to human nutrition and are widely used as pharmaceutically active compounds. However, native plants produce a limited amount of terpenes restricting metabolite yield of terpene-related metabolites. Exponential growth in the plant metabolome data and the requirement of alternative approaches for producing the desired amount of terpenoids, has redirected plant biotechnology research to plant metabolic engineering, which requires in-depth knowledge and precise expertise about dynamic plant metabolic pathways and cellular physiology. Metabolic engineering is an assuring tool for enhancing the concentration of terpenes by adopting specific strategies such as overexpression of the key genes associated with the biosynthesis of targeted metabolites, controlling the modulation of transcription factors, downregulation of competitive pathways (RNAi), co-expression of the biosynthetic pathway genes in heterologous system and other combinatorial approaches. Microorganisms, fast-growing host plants (such as Nicotiana benthamiana), and cell suspension/callus cultures have provided better means for producing valuable terpenoids. Manipulation in the biosynthetic pathways responsible for synthesis of terpenoids can provide opportunities to enhance the content of desired terpenoids and open up new avenues to enhance their production. This review deliberates the worth of metabolic engineering in medicinal plants to resolve issues associated with terpenoid production at a commercial scale. However, to bring the revolution through metabolic engineering, further implementation of genome editing, elucidation of metabolic pathways using omics approaches, system biology approaches, and synthetic biology tactics are essentially needed.

The plant LIM proteins: unlocking the hidden attractions.

MAIN CONCLUSION: The plant LIMs comprise two sub-families with one (DA1/DAR) and two (2LIM) LIM domains. This review comprehensively discussed the structure and potential role of this protein family in diverse area of plant biology. The description of first eukaryote lineage-specific plant LIM domain (LIN11, ISL1, and MEC3) proteins was observed in Helianthus long back. The successive study of LIM proteins in diverse plants has shown its vital relation to development, metabolism and defence. This nascent gene family has been worked out for their role in actin dynamics, organ size determination and transcription regulation. On grounds of protein architecture, two sub-families have been delineated as DA1/DAR (one LIM domain) and 2LIMs (two LIM domains). The genomic and expression study guides to the identification of diverse sub-categories. The significance of 2LIMs in regulation of actin dynamics leading to pollen growth and development has prospects to understand the plant reproductive behaviour. Interestingly, new facet of these LIMs as a transcriptional regulator in biological pathway/biosynthesis was also reported. Recently, the cumulative contribution of these features was also recognized for obtaining good quality fibre, thus giving translational outlook to this family. The DA1/DAR proteins are orchestrated with additional domains and provide a key role in regulation of organ size and tolerance to biotic and abiotic stress. This review will focus the journey of plant LIMs till date and will cover details of its structure, type, classification and functional relevance. This will provide insight to identify the potential of this gene family in the improvement of desired crop features.

Photo-induced biosynthesis of silver nanoparticles from aqueous extract of Dunaliella salina and their anticancer potential.

The synthesis of silver nanoparticles (AgNPs) via green route, using biological entities is an area of interest, because one of the potential applications in the nanomedicine. In the present study, we have developed photo-induced, ecofriendly, low cost method for biosynthesis of the stable silver nanoparticles using aqueous extract of Dunaliella salina (AED) which act as both reducing as well as stabilizing agent. Biosynthesis of the AgNPs was optimized as: sunlight exposure (30min), AED (5% (v/v)) and AgNO3 (4mM). Biosynthesis of AgNPs was monitored by using UV-Vis spectroscopy which exhibited sharp SPR band at 430nm after 30min of bright sunlight exposure. SEM and TEM analyses confirmed the presence of spherical AgNPs with average size of 15.26nm. Crystalline nature of AgNPs was confirmed by SAED and XRD analyses where Braggs reflection pattern at (111), (200), (220) and (311) corresponded to face centered cubic crystal lattice of metallic silver. FTIR analysis revealed the involvement of various functional groups present in AED. AFM analysis confirmed the average surface roughness of synthesized AgNPs as 8.48nm. AgNPs were also screened for anticancer potential using assay of calcein AM/PI, Annexin/PI and cancer biomarkers against cancer cell line (MCF-7), while normal cell line (MCF-10A) were kept as control. Interestingly, anticancer potential was comparable to the known anticancer drug (Cisplatin), and was not detrimental to the normal cell line. Therefore, such green synthesized AgNPs may be explored as anticancer agent.

ROS mediated pro-apoptotic effects of Tinospora cordifolia on breast cancer cells.

The inevitable development of chemoresistance and unmanageable side effects are the major therapeutic challenges in management of breast cancer imposing an urgent need for identification of novel therapeutic agents. In the present investigation, we report anti-proliferative activity of chloroform fraction of Tinospora cordifolia (TcCF), an Ayurvedic medicinal plant, on breast cancer cells. We found that TcCF inhibited growth of breast cancer cells, MDA-MB-231 and MCF-7. More interestingly, we observed TcCF treatment increased intra-cellular ROS levels, altered expression of pro and anti-apoptotic genes, decreased colony formation ability and induced apoptosis in breast cancer cells. We also found that inhibition of ROS abrogated TcCF induced apoptosis in breast cancer cells, emphasizing the role ROS in TcCF induced breast cancer cell death. Furthermore, we identified the presence of pharmacologically active compounds like rutin and quercetin which account for the anti-cancer property of TcCF against breast cancer cells. These data show TcCF is a promising anti-cancer agent against breast cancer cells.