Aims:  To investigate whether the relative abundance of the Bacteroidetes and Firmicutes divisions in pigs is different between obese and lean animals. Methods and Results:  Group‐specific primers were designed to target the 16S rRNA genes of Bacteroidetes and Firmicutes present in the gut. After the validation of their specificity, these primers were used in the real‐time PCR quantification of all Bacteria, Firmicutes division, Bacteroidetes division and Bacteroides spp. in the faecal samples of obese and lean pigs from Banna mini‐pig inbred line. The obese pigs had a ∼61% fewer percentage (based on all Bacteria) of Bacteroidetes division (P = 0·033) and a ∼56% fewer proportion of Bacteroides spp. (P = 0·047) than the lean pigs. The proportions of both Bacteroidetes and Bacteroides had a negative correlation (P < 0·01) with the body weight. Conclusion:  The results suggested that the fat storage might affect the proportion of Bacteroidetes division in the gut. Significance and Impact of the Study:  The real‐time PCR assays developed for Firmicutes and Bacteroidetes will be useful for investigating the composition of gut microbiota.

Obesity is an established risk factor for many diseases including intestinal cancer. One of the responsible mechanisms is the chronic inflammation driven by obesity. However, it remains to be defined whether diet-induced obesity exacerbates the intestinal inflammatory status by cytokines produced in adipose tissue or the high fat diet first alters the gut microbiota and then drives intestinal inflammation. To address this question, we fed C57BL/6 mice with a high fat diet (HF, 60%) and sacrificed them sequentially after 8, 12, and 16 weeks, and then compositions of gut microbiota and expressions of antimicrobial peptides were determined. The compositions of gut microbiota were altered at 8 wk HF feeding, followed with reduced Paneth antimicrobial peptides lysozyme and Reg IIIγ after 12 and 16 wk HF feeding (p < 0.05), whereas elevations of circulating inflammatory cytokines IFNγ and TNF-α were observed until feeding a HF diet for 16 weeks (p < 0.05). These results indicated that high fat diet may stimulate intestinal inflammation via altering gut microbiota, and it occurs prior to the potential influence by circulating inflammatory cytokines. These findings emphasized the importance of microbiota, in addition to adipose tissue per se, in driving intestinal inflammation, which may thereafter promote intestinal tumorigenesis.

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Heat shock transcription factors (Hsfs) play vital roles in the regulation of tolerance to various stresses in living organisms. To dissect the mechanisms of the Hsfs in potato adaptation to abiotic stresses, genome and transcriptome analyses of Hsf gene family were investigated in Solanum tuberosum L. Twenty-seven StHsf members were identified by bioinformatics and phylogenetic analyses and were classified into A, B, and C groups according to their structural and phylogenetic features. StHsfs in the same class shared similar gene structures and conserved motifs. The chromosomal location analysis showed that 27 Hsfs were located in 10 of 12 chromosomes (except chromosome 1 and chromosome 5) and that 18 of these genes formed 9 paralogous pairs. Expression profiles of StHsfs in 12 different organs and tissues uncovered distinct spatial expression patterns of these genes and their potential roles in the process of growth and development. Promoter and quantitative real-time polymerase chain reaction (qRT-PCR) detections of StHsfs were conducted and demonstrated that these genes were all responsive to various stresses. StHsf004, StHsf007, StHsf009, StHsf014, and StHsf019 were constitutively expressed under non-stress conditions, and some specific Hsfs became the predominant Hsfs in response to different abiotic stresses, indicating their important and diverse regulatory roles in adverse conditions. A co-expression network between StHsfs and StHsf -co-expressed genes was generated based on the publicly-available potato transcriptomic databases and identified key candidate StHsfs for further functional studies.

Gut dysbiosis induced by high fat diet (HF) or obesity is a predisposing factor to develop diverse inflammatory diseases. Polyphenols and fibers, often eaten together, have been reported to have prebiotic actions, but their health promoting benefits still need to be further characterized and defined. This study attempted to understand how polyphenol rutin and polysaccharide inulin influence intestinal health in mouse model fed a HF (60 kcal%) diet. A total of 48 C57BL/6J mice were divided into four groups fed with a low fat (10% kcal%) control diet (LC), a high fat control diet (HC), a high-fat diet supplemented with rutin (HR), or a high-fat diet supplemented rutin and inulin (HRI) for 20 weeks. Rutin supplementation reduced the HF diet-induced increase of Firmicutes/Bacteroidetes (F/B) ratio, Deferribacteraceae population and plasma lipopolysaccharide (LPS) (p < 0.05); ameliorated inflammation as indicated by the decreased circulating inflammatory cytokines (p < 0.05) and the reduced expressions of intestinal inflammatory mediators (p < 0.05); and attenuated the endoplasmic reticulum (ER) stress in Paneth cells as indicated by the decreased expressions of the ER markers (p < 0.05). Compared to the rutin supplementation alone, the co-administration of rutin with inulin improved the utilization of rutin as indicated by its decreased excretion, suppressed a number of harmful bacteria including Deferribacteraceae and Desulfovibrionaceae (p < 0.05), and further reduced the expression of the key inflammatory cytokine TNF-α and increased the production of butyrate, despite the supplementation of inulin reversed the decrease of body weight induced by rutin supplementation due to an increased food intake. Taken together, our data demonstrated that rutin supplementation ameliorated the inflammatory status and ER stress in Paneth cells under a HF-induced obese state, and its co-administration with inulin further mitigated the inflammatory status, indicating the potential to combine polyphenol rutin and the polysaccharide inulin as a dietary strategy to ameliorate gut dysbiosis, to improve inflammatory status and thereby to reduce medical disorders associated with HF-induced obesity.

Climate warming is subjecting plants to heat stress, which can affect their physiological processes thereby impacting their growth, development, and productivity. Potato (Solanum tuberosum L.) is a staple food worldwide, but potato crops are very sensitive to heat stress. We have studied the effects of heat stress on the leaf chlorophyll content, plant growth, and tuber yield of 55 commercial potato cultivars in clonal tests under heat-stress conditions [HS; 35 °C (day), 28 °C (night)] and control (non-stress) conditions [CK; 22 °C (day), 18 °C (night)]. The potato cultivars varied in their response to heat stress. Overall, heat stress reduced leaf size, increased the SPAD index values for leaf chlorophyll by up to 65%, and increased plant height by 64%, but severely reduced (by 93%) the mass of the largest tuber. The HS:CK SPAD ratios positively correlated with the HS:CK plant height ratio, mass of the largest tuber under heat stress, and the HS:CK ratio for mass of the largest tuber. Potato cultivars displayed a correlated response to heat stress for their leaf chlorophyll content, plant height, and tuber mass. We have identified the most heat-tolerant and heat-susceptible cultivars for these traits. Under heat-stress conditions, potato cultivars tend not to show as much reduction in tuber mass if the plants have greater increases in leaf chlorophyll content and plant height.

Background Compared with white-fleshed sweetpotato (WFSP), purple-fleshed sweetpotato (PFSP) is a desirable resource for functional food development because of the abundant anthocyanin accumulation in its tuberous roots. Some studies have shown that the expression regulation mediated by miRNA plays an important role in anthocyanin biosynthesis in plants. However, few miRNAs and their corresponding functions related to anthocyanin biosynthesis in tuberous roots of sweetpotato have been known. Results In this study, small RNA (sRNA) and degradome libraries from the tuberous roots of WFSP (Xushu-18) and PFSP (Xuzishu-3) were constructed, respectively. Totally, 191 known and 33 novel miRNAs were identified by sRNA sequencing, and 180 target genes cleaved by 115 known ib-miRNAs and 5 novel ib-miRNAs were identified by degradome sequencing. Of these, 121 miRNAs were differently expressed between Xushu-18 and Xuzishu-3. Integrated analysis of sRNA, degradome sequencing, GO, KEGG and qRT-PCR revealed that 26 differentially expressed miRNAs and 36 corresponding targets were potentially involved in the anthocyanin biosynthesis. Of which, an inverse correlation between the expression of ib-miR156 and its target ibSPL in WFSP and PFSP was revealed by both qRT-PCR and sRNA sequencing. Subsequently, ib-miR156 was over-expressed in Arabidopsis . Interestingly, the ib-miR156 over-expressing plants showed suppressed abundance of SPL and a purplish phenotype. Concomitantly, upregulated expression of four anthocyanin pathway genes was detected in transgenic Arabidopsis plants. Finally, a putative ib-miRNA-target model involved in anthocyanin biosynthesis in sweetpotato was proposed. Conclusions The results represented a comprehensive expression profiling of miRNAs related to anthocyanin accumulation in sweetpotato and provided important clues for understanding the regulatory network of anthocyanin biosynthesis mediated by miRNA in tuberous crops. Electronic supplementary material The online version of this article (10.1186/s12870-019-1790-2) contains supplementary material, which is available to authorized users.

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