Liu Clarke, J. | bioRxiv Science

bioRxiv2020

Dietary propionate induces intestinal oxidative stress via inhibition of SIRT3-mediated SOD2 depropionylation

Propionate is a commonly used preservative in various food and feedstuffs and has been regarded as a food additive without safety concerns. However, we observed that dietary propionate supplementation induced intestinal damage in the context of high fat diet (HFD) in zebrafish. The intestinal damage was attributable to oxidative stress owing to impaired antioxidant capacity, which was caused by compromised SOD2 activity in the intestine. Global lysine propionylation analysis of the intestinal samples showed that SOD2 was propionylated at K132, and further biochemical assays demonstrated that K132 propionylation suppressed SOD2 activity. In addition, SIRT3 could directly interact with SOD2 and played an important role in regulating SOD2 activity via modulating depropionylation, and the enhanced SOD2 propionylation in zebrafish fed high fat plus propionate diet was attributable to reduced SIRT3 expression. Finally, we reveal that intestinal oxidative stress resulting from SOD2 propionylation contributed to the compositional change of gut microbiota, which further deteriorated intestinal oxidative stress independent of SIRT3. Collectively, the results in this study reveal a link between protein propionylation and intestine health, and suggest potential risk of a widely used food preservative in HFD context.

cell biology↗

bioRxiv2018

Transcriptome and metabolome analysis provide insights into root and root released organic anion responses to phosphorus deficiency in oat

Root and root-released organic anions play important roles in uptake of phosphorus (P), an essential macronutrient for food production. Oat, ranking sixth in the worlds cereal production, contains valuable nutritional compounds and can withstand poor soil conditions. The aim of this research was to investigate root transcriptional and metabolic responses of oat grown under P-deficient and P-sufficient conditions. We conducted a hydroponic experiment and measured root morphology, organic anions exudation, and analysed changes in the transcriptome and metabolome, to understand oat root adaptation to P deficiency. We found that oat roots showed enhanced citrate and malate exudation after four weeks of P-deficiency. After 10 days of P-deficiency, we identified 9371 differentially expressed transcripts with a two-fold or greater change (p < 0.05): forty-eight sequences predicted to be involved in organic anion biosynthesis and efflux were consistently up-regulated; twenty-four up-regulated transcripts in oat were also found up-regulated upon P starvation in rice and wheat under similar conditions. Phosphorylated metabolites (i.e. glucose-6-phosphate, myo-inositol-phosphate) reduced dramatically, while citrate and malate, some sugars and amino acids increased slightly in P-deficient oat roots. Our data provide new insights into the root responses to P deficiency and root-released organic anions in oat.\n\nHighlightWe found oat- a monocot food crop, showed high exudation rate of citrate under phosphorus deficiency; root transcriptome and metabolome were then investigated to understand oat adaptation to P deficiency.

plant biology↗