In Vitro Comparative Study on Antineoplastic Effects of Pinoresinol and Lariciresinol on Healthy Cells and Breast Cancer-Derived Human Cells.

Background: Herbal medicines are the preferred anticancer agents due to their lower cytotoxic effects on healthy cells. Plant lignans play an important role in treating various diseases, especially cancer. The present study aimed to evaluate the effect of podophyllotoxin, pinoresinol, and lariciresinol on cellular toxicity and inducing apoptosis in fibroblasts, HEK-293, and SkBr3 cell lines. Methods: An in vitro study was conducted from 2017 to 2019 at the Faculty of Biological Sciences, Tarbiat Modares University (Tehran, Iran). The cell lines were treated for 24 and 48 hours with different concentrations of lignans. Cell viability and apoptosis were examined using MTT and flow cytometry, respectively. Expression levels of cell cycle and apoptosis regulator genes were determined using quantitative real-time polymerase chain reaction. Data were analyzed using a two-way analysis of variance followed by Tukey's HSD test. P<0.05 was considered statistically significant. Results: Podophyllotoxin significantly increased apoptosis in fibroblast cells compared to pinoresinol and lariciresinol (P<0.001). The percentage of cell viability of fibroblast cells treated for 48 hours with pinoresinol, lariciresinol, and podophyllotoxin was reduced by 49%, 47%, and 36%, respectively. Treatment with pinoresinol and lariciresinol significantly overexpressed pro-apoptotic genes and underexpressed anti-apoptotic genes in SkBr3 cells (P<0.001). SkBr3 cells treated with lariciresinol significantly reduced gene expression (P<0.001). Conclusion: Pinoresinol and lariciresinol can potentially be used as new therapeutic agents for the treatment of breast cancer.

Improvement of Lutein Production in Auxenochlorella protothecoides Using Its Genome-Scale Metabolic Model and a System-Oriented Approach.

Lutein is a valuable metabolite widely used in the food, pharmaceutical, cosmetic, and aquaculture industries. Marigold flowers are the most common source of commercial lutein, but cultivation area, weather conditions, and high manpower costs are among the disadvantages of lutein production from marigold flowers. Microalgae are an excellent alternative to plant sources of lutein as they do not have the limitations of plant extraction. Auxenochlorella protothecoides is a promising candidate for commercial production of lutein. In the present research, a genome-scale metabolic model was applied to introduce some strategies to improve lutein production in A. protothecoides. The effective reactions to improve lutein production were determined based on analysis of multiple optimal solutions. The enzymatic regulators of candidate reactions were identified using the BRENDA database. The effect of 13 activators was investigated experimentally. Our results showed that sodium citrate has the greatest effect on lutein production, so it was introduced as the most effective compound for increasing lutein production by A. protothecoides.

Molecular Characterization of a New Ecotype of Holoparasitic Plant Orobanche L. on Host Weed Xanthium spinosum L.

A species of Orobanche was observed on spiny cocklebur (Xanthium spinosum) for the first time in Iran and tentatively was named IR-Iso.This study was conducted to make a phylogenetic analysis of the Orobanche using 5.8S rRNA region sequences, and also to better understand its sequence pattern. The full-length ITS1-ITS2 region of the new Orobanche isolate was PCR-amplified from the holoparasitic plant parasitizing X. spinosum. Sequences of the amplicons from the isolate were 100% identical but differed by 5.6-6.7% from most homologous GenBank accessions to 37.9% divergence from distant species. The analysis of the molecular variance showed that variation between-population (61.9%, SE = 0.04) was larger than within-population. Neighbor-joining analysis placed the Iranian isolate in the same clade as most of the Orobanche and Phelipanche species. The isolate was more closely related to Orobanche aegyptiaca (from China), and this was confirmed by using a structure analysis. However, complementary analyses showed that the Iranian isolate has a unique nucleotide substitution pattern, and hence it was considered as an ecotype of O. aegyptiaca (ecotype Alborzica). In this paper we report on the association between this new ecotype of Orobanche and X. spinosum.

Proteomic analysis of wheat contrasting genotypes reveals the interplay between primary metabolic and regulatory pathways in anthers under drought stress.

Reproductive stage is very sensitive to various forms of environmental stresses such as drought stress. The proteomic analysis of anther during pollen development in response to drought stress was performed using a label-free quantitative shotgun proteomic technique to define the underlying molecular principles in two contrasting wheat genotypes Shiraz (susceptible) and D-10 (tolerant). Drought stress resulted in around two-fold decline in seed setting capacity and pollen viability in the Shiraz genotype compared to D-10. A Partial Least Square Discriminant Analysis (PLS-DA) of proteomic data revealed the abundance of 131 differentially abundant proteins significantly contributing in separation of drought tolerant and susceptible genotypes under normal and stress conditions. Proteins involved in cellular respiration, carbohydrate metabolism, RNA metabolism, and vesicle trafficking showed completely different responses in two genotypes. These proteins may maintain hexose pool and energy level and control regulation of transcription and transport. Furthermore, different members of functional groups such as protein biosynthesis and degradation, chromatin organization, and cytoskeleton dynamics were differentially abundant in response to stress in both genotypes which suggest their function in both genotypes to maintain minimum pollen viability/ fertility under drought stress. In conclusion, our findings revealed various metabolic and regulatory pathways underlying survival strategies required for pollen fertility and viability. SIGNIFICANCE: Drought caused by global climate change decreases cereal grain productivity worldwide. Yield losses due to water stress have been reported for major small grain cereal including wheat. Our findings highlighted the importance of key proteins in wheat adaptation to drought stress at reproductive stage. The obtained data showed that differentially abundant proteins in drought tolerant wheat genotype was remarkably associated with cellular respiration, carbohydrate metabolism, RNA metabolism, and vesicle trafficking. These results revealed fundamental data to elucidate the complexity of pollen fertility and viability under drought stress condition in wheat.

The contrasting microRNA content of a drought tolerant and a drought susceptible wheat cultivar.

Drought stress represents one of the most common stresses affecting the productivity of crop plants. A rather recently discovered component of the plant response to drought is the cellular population of microRNAs. Here, the microRNA content was revealed of two bread wheat cultivars contrasting strongly with respect to the ability to withstand drought stress. A total of 1813 miRNAs was identified, grouped into 106 families. Some 104 of these miRNAs were predicted to match 212 novel miRNA precursors. In the drought tolerant cultivar (SM), 105 (33 known and 72 novel) miRNAs were altered in abundance by the imposition of drought stress, while the equivalent number in the more sensitive cultivar (SW) was 51 (20 and 31). An in silico analysis predicted that these miRNAs target at least 1959 genes in SM and 1111 in SW, suggesting their broad contribution to the drought stress response. Among the target genes were several known stress-related genes, encoding, for example, superoxide dismutase, various MYB transcription factors, various ABA signaling proteins and various MADS-box transcription factors. In many cases, the more susceptible cultivar SW behaved in a contrasting manner. The suggestion is that miRNAs represent an important aspect of the drought stress response, post-transcriptionally regulating a range of stress-related genes.

A Proteomics Approach to Discover Drought Tolerance Proteins in Wheat Pollen Grain at Meiosis Stage.

Plants reproductive phase, when grain yield and consequently farmers' investment is most in jeopardy, is considered as the most sensitive stage to drought stress. In this study, we aimed to explore the proteomic response of wheat anther at meiosis stage in a drought tolerant, Darab, and susceptible, Shiraz, wheat genotypes. Wheat plants were exposed to drought stress at meiosis stage for four days under controlled environmental conditions. Then, anthers from both genotypes were sampled, and their proteomes were examined via quantitative proteomics analysis. Our results demonstrated that short-term stress at meiosis stage reduced plant seed-setting compared to well-watered plants. This reduction was more pronounced in the susceptible genotype, Shiraz, by 51%, compared to the drought tolerant Darab by 14.3%. Proteome analysis revealed that 60 protein spots were drought responsive, out of which 44 were identified using a mass spectrometer. We observed a dramatic up-regulation of several heat shock proteins, as well as induction of Bet v I allergen family proteins, peroxiredoxin-5, and glutathione transferase with similar abundance in both genotypes. However, the abundance of proteins such as several stress response related proteins, including glutaredoxin, proteasome subunit alpha type 5, and ribosomal proteins showed a different response to drought stress in two genotypes. The differential abundance of proteins in two genotypes may suggest mechanisms by which tolerant genotype cope with drought stress. To the best of our knowledge, this is the first proteome analysis of plant reproductive tissue response to drought stress in wheat and could broaden our insight into plant adaptation to drought stress.