Biotrophy-necrotrophy switch in pathogen evoke differential response in resistant and susceptible sesame involving multiple signaling pathways at different phases.

Infection stages of charcoal rot fungus Macrophomina phaseolina in sesame revealed for the first time a transition from biotrophy via BNS (biotrophy-to-necrotrophy switch) to necrotrophy as confirmed by transcriptional studies. Microscopy using normal and GFP-expressing pathogen showed typical constricted thick intercellular bitrophic hyphae which gave rise to thin intracellular necrotrophic hyphae during BNS and this stage was delayed in a resistant host. Results also show that as the pathogen switched its strategy of infection, the host tailored its defense strategy to meet the changing situation. Less ROS accumulation, upregulation of ROS signaling genes and higher antioxidant enzyme activities post BNS resulted in resistance. There was greater accumulation of secondary metabolites and upregulation of secondary metabolite-related genes after BNS. A total of twenty genes functioning in different aspects of plant defense that were monitored over a time course during the changing infection phases showed a coordinated response. Experiments using phytohormone priming and phytohormone inhibitors showed that resistance resulted from activation of JA-ET signaling pathway. Most importantly this defense response was more prompt in the resistant than the susceptible host indicating that a resistant host makes different choices from a susceptible host during infection which ultimately influences the severity of the disease.

Effects of dietary milled seed mixture on fatty acid status and inflammatory markers in patients on hemodialysis.

BACKGROUND: Plant seeds have gained interest for their health benefits due to their fatty acid content. The objective of this study was to determine the effects of dietary consumption of milled sesame/pumpkin/flax seed mixture on glycemic control, serum lipids, phospholipid fatty acid status, and inflammatory factors in patients on hemodialysis. METHODS: Thirty patients with well nutrition status (18 male, 12 female) were enrolled in the study. Participants consumed 30 g of milled sesame/pumpkin/flax (6 g/6 g/18 g, resp.) seeds mixture added to their habitual diet. RESULTS: Total n-6 and n-3 polyunsaturated fatty acids and levels of linoleic, dihomo-gamma-linolenic (DGLA), arachidonic, alpha-linolenic (ALA), eicosapentaenoic, docosapentaenoic, and docosahexaenoic (DHA) acid were increased after 12 weeks of supplementation. A significant decrease of the serum triglyceride level (P < 0.001), glucose, insulin, calculated IR HOMA (P < 0.05), and inflammatory markers (TNF-alpha, IL-6, and hs-CRP, P < 0.001) was observed after seed mixture treatment. The serum levels of CRP and TNF-alpha negative correlate with ALA, DHA, and DGLA. CONCLUSION: Results of this study indicated that dietary milled sesame/pumpkin/flax seed mixture added to a habitual diet lowered triglyceride and CRP, TNF-alpha, IL-6 levels, affect glycemic control and improved fatty acid profile and pruritus symptoms in hemodialysis patients.

Effect of chloride ions on anthrasesamone C production in a Sesamum indicum hairy root culture and identification of the precursor for its abiotic formation.

The content of anthrasesamone C (5), a rare chlorine-containing anthraquinone, in a hairy root culture of Sesamum indicum increased with increasing chloride ion concentration in the culture medium and reached a maximum at 100 mM. However, the amount of anthrasesamone C (5) in the extract obtained from the hairy roots was increased by incubating the extract. This result suggests that anthrasesamone C (5) was produced from an unidentified metabolite by an abiotic process. 2,3-Epoxyanthrasesamone B (1), a precursor for the non-enzymatic formation of anthrasesamone C (5), was isolated from S. indicum hairy roots cultured in a chloride-deficient medium. Its structure was elucidated to be 2,3-epoxy-9,10-dihydroxy-2-(4-methylpent-3-en-1-yl)-2,3-dihydroanthracene-1,4-dione by spectroscopic methods.

Size and stability of reconstituted sesame oil bodies.

Oil bodies of sesame seeds comprise a triacylglycerol matrix, which is surrounded by a monolayer of phospholipids embedded with unique proteins, mainly structural proteins termed oleosins. Artificial oil bodies were successfully reconstituted with various compositions of triacylglycerols, phospholipids, and oil-body proteins. The sizes of reconstituted oil bodies displayed a normal distribution with an average size proportional to the ratio of triacylglycerols to oil-body proteins. Both thermostability and structural stability of reconstituted oil bodies decreased as their sizes increased, and vice versa. Proteinase K digestion indicated that oleosins anchored both native and reconstituted oil bodies via their central hydrophobic domains. The stability of reconstituted oil bodies, as well as the purified ones from sesame seeds, could be substantially enhanced after their surface proteins were cross-linked by glutaraldehyde or genipin.