Ectopic Expression of FvVND4c Promotes Secondary Cell Wall Thickening and Flavonoid Accumulation in Fragaria vesca.

Secondary cell wall (SCW) thickening has a significant effect on the growth and development of plants, as well as in the resistance to various biotic and abiotic stresses. Lignin accounts for the strength of SCW. It is synthesized through the phenylpropanoid pathway that also leads to flavonoid synthesis. The coupling strategies for lignin and flavonoid syntheses are diverse in plants. How their syntheses are balanced by transcriptional regulation in fleshy fruits is still unclear. The diploid strawberry (Fragaria vesca) is a model for fleshy fruits research due to its small genome and wide scope of genetic transformation. SCW thickening is regulated by a multilevel transcriptional regulatory network wherein vascular-related NAC domains (VNDs) act as key regulators. In this study, we systematically characterized VNDs in Fragaria vesca and explored their functions. The overexpression of FvVND4c in diploid strawberry fruits resulted in SCW thickening and fruit color changes accompanied with the accumulation of lignin and flavonoids. Genes related to these phenotypes were also induced upon FvVND4c overexpression. Among the induced genes, we found FvMYB46 to be a direct downstream regulator of FvVND4c. The overexpression of FvMYB46 resulted in similar phenotypes as FvVND4c, except for the color change. Transcriptomic analyses suggest that both FvVND4c and FvMYB46 act on phenylpropanoid and flavonoid biosynthesis pathways, and induce lignin synthesis for SCW. These results suggest that FvVND4c and FvMYB46 cooperatively regulate SCW thickening and flavonoid accumulation in Fragaria vesca.

FvNST1b NAC Protein Induces Secondary Cell Wall Formation in Strawberry.

Secondary cell wall thickening plays a crucial role in plant growth and development. Diploid woodland strawberry (Fragaria vesca) is an excellent model for studying fruit development, but its molecular control of secondary wall thickening is largely unknown. Previous studies have shown that Arabidopsis NAC secondary wall thickening promoting factor1 (AtNST1) and related proteins are master regulators of xylem fiber cell differentiation in multiple plant species. In this study, a NST1-like gene, FvNST1b, was isolated and characterized from strawberry. Sequence alignment and phylogenetic analysis showed that the FvNST1b protein contains a highly conserved NAC domain, and it belongs to the same family as AtNST1. Overexpression of FvNST1b in wild-type Arabidopsis caused extreme dwarfism, induced ectopic thickening of secondary walls in various tissues, and upregulated the expression of genes related to secondary cell wall synthesis. In addition, transient overexpression of FvNST1b in wild-type Fragaria vesca fruit produced cells resembling tracheary elements. These results suggest that FvNST1b positively regulates secondary cell wall formation as orthologous genes from other species.

Recurrence of moderate to severe ulcerative colitis after fecal microbiota transplantation treatment and the efficacy of re-FMT: a case series.

BACKGROUND: Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD), the pathogenesis of which is complicated, and it is difficult to treat. In recent years, the emerging fecal microbiota transplantation (FMT) has shown good effects in UC treatment and is therefore accepted by increasing numbers of patients. Our hospital has carried out FMT since 2017, and has achieved good results in UC treatment. We have found in our clinical work that the efficacy of re-FMT after recurrence decreased. This is difference from reported literatures. In order to attract clinical attention, here we selected typical cases for analysis. METHODS: Among all UC patients who received FMT in our hospital, 12 patients with moderate to severe UC were selected. They all received multiple FMT and were followed up for 52 weeks. Besides, none of them had other underlying diseases. Colonoscopy images of patients were presentated, SCCAI and UCDAI were used assess the effect of FMT. RESULTS: On the whole, FMT has a significant effect on moderate to severe UC. Of the 12 patients, 11 (91.7%) achieved a clinical response, 9 (75.0%) achieved clinical remission, and only one patient did not respond to FMT treatment. However, 6 patients relapsed within 52 weeks after remission, with a recurrence rate of 54.5%. Four of the six relapsed patients received FMT again, but the efficacy of FMT after relapse was significantly lower than that of the initial FMT. Fortunately, compared to before the initial FMT treatment, the severity of the disease after relapse was significantly reduced. CONCLUSION: FMT has a good effect on the relief of moderate to severe UC. However, the effect of FMT treatment after relapse is reduced. For patients who relapse after remission, the efficacy of FMT reapplication requires more experiments to verify.

Simple promotion of Cas9 and Cas12a expression improves gene targeting via an all-in-one strategy.

Gene targeting (GT) is a promising tool for precise manipulation of genome sequences, however, GT in seed plants remains a challenging task. The simple and direct way to improve the efficiency of GT via homology-directed repair (HDR) is to increase the frequency of double-strand breaks (DSBs) at target sites in plants. Here we report an all-in-one approach of GT in Arabidopsis by combining a transcriptional and a translational enhancer for the Cas expression. We find that facilitating the expression of Cas9 and Cas12a variant by using enhancers can improve DSB and subsequent knock-in efficiency in the Arabidopsis genome. These results indicate that simply increasing Cas protein expression at specific timings - egg cells and early embryos - can improve the establishment of heritable GTs. This simple approach allows for routine genome engineering in plants.

Assessing the efficacy and safety of fecal microbiota transplantation and probiotic VSL#3 for active ulcerative colitis: A systematic review and meta-analysis.

BACKGROUND: Fecal microbiota transplantation is an effective treatment for many gastrointestinal diseases, such as Clostridium difficile infection and inflammatory bowel disease, especially ulcerative colitis. Changes in colonic microflora may play an important role in the pathogenesis of ulcerative colitis, and improvements in the intestinal microflora may relieve the disease. Fecal bacterial transplants and oral probiotics are becoming important ways to relieve active ulcerative colitis. PURPOSE: This systematic review with meta-analysis compared the efficacy and safety of basic treatment combined with fecal microbiota transplantation or mixed probiotics therapy in relieving mild to moderate ulcerative colitis. METHODS: The PubMed, Embase, and Cochrane libraries (updated September 2019) were searched to identify randomized, placebo-controlled, or head-to-head trials assessing fecal microbiota transplantation or probiotic VSL#3 as induction therapy in active ulcerative colitis. We analyze data using the R program to obtain evidence of direct comparison and to generate intermediate variables for indirect treatment comparisons. RESULTS: Seven randomized, double-blind, placebo-controlled trials were used as the sources of the induction data. All treatments were superior to placebo. In terms of clinical remission and clinical response to active ulcerative colitis, direct comparisons showed fecal microbiota transplantation (OR = 3.47, 95% CI = 1.93-6.25) (OR = 2.48, 95% CI = 1.18-5.21) and mixed probiotics VSL#3 (OR = 2.40, 95% CI = 1.49-3.88) (OR = 3.09, 95% CI = 1.53-6.25) to have better effects than the placebo. Indirect comparison showed fecal microbiota transplantation and probiotic VSL#3 did not reach statistical significance either in clinical remission (RR = 1.20, 95% CI = 0.70-2.06) or clinical response (RR = 0.95, 95% CI = 0.62-1.45). In terms of safety, fecal microbiota transplantation (OR = 1.15, 95% CI = 0.51-2.61) and VSL #3 (OR = 0.90, 95% CI = 0.33-2.49) showed no statistically significant increase in adverse events compared with the control group. In terms of serious adverse events, there was no statistical difference between the fecal microbiota transplantation group and the control group (OR = 1.29, 95% CI = 0.46-3.57). The probiotics VSL#3 seems more safer than fecal microbiota transplantation, because serious adverse events were not reported in the VSL#3 articles. CONCLUSIONS: Fecal microbiota transplantation or mixed probiotics VSL#3 achieved good results in clinical remission and clinical response in active ulcerative colitis, and there was no increased risk of adverse reactions. There was no statistical difference between the therapeutic effect of fecal microbiota transplantation and that of mixed probiotics VSL#3. However, the use of fecal microbiota transplantation and probiotics still has many unresolved problems in clinical applications, and more randomized controlled trials are required to confirm its efficacy.