Plant defense against virus diseases; growth hormones in highlights

Movahedi

et al. 2020

Front. Microbiol.

PtDef cloned from Populus trichocarpa contained eight cysteine domains specific to defensins. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis showed that PtDef was expressed in all tissues tested, with lower expression in leaves and higher expression in petioles, stems, and roots. Purified fused PtDef inhibited Aspergillus niger, Alternaria Nees, Mucor corymbifer, Marssonina populi, Rhizopus sp., and Neurospora crassa. PtDef also inhibited the growth of Escherichia coli by triggering autolysis. PtDef overexpression in Nanlin895 poplar (Populus × euramericana cv. Nanlin895) enhanced the level of resistance to Septotinia populiperda. qRT-PCR analysis also showed that the expression of 13 genes related to salicylic acid (SA) and jasmonic acid (JA) signal transduction differed between transgenic and wild-type (WT) poplars before and after inoculation, and that PR1-1 (12-72 h), NPR1-2, TGA1, and MYC2-1 expression was higher in transgenic poplars than in WT. During the hypersensitivity response (HR), large amounts of H 2 O 2 were produced by the poplar lines, particularly 12-24 h after inoculation; the rate and magnitude of the H 2 O 2 concentration increase were greater in transgenic lines than in WT. Overall, our findings suggest that PtDef, a defensin-encoding gene of P. trichocarpa, could be used for genetic engineering of woody plants for enhanced disease resistance.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characterization, Expression Profiling, and Functional Analysis of PtDef, a Defensin-Encoding Gene From Populus trichocarpa

Movahedi

et al. 2020

Front. Microbiol.

“…In addition, it seems that ascidian gut microorganisms could directly synthesize some plant-type and insect-type hormones, such as salicylic acid, stearidonic acid, juvenile hormone I, podecdysone B, Iloprost, Nicotinamide. Those plant hormones could induce the wound defense against diseases [55,56], and those insect hormones were involved in improving chemical defense and immunity [57][58][59][60].…”

Section: Discussionmentioning

confidence: 99%

Seasonal Dynamics and Starvation Impact on the Gut Microbiome of Urochordate Ascidian Halocynthia roretzi

Gao²,

Yang

et al. 2020

Preprint

BackgroundGut microbiota plays important roles in host animal physiology, homeostasis, metabolism, and environmental adaptation while the interplay between the gut microbiome and urochordate ascidian, the most closet relative of vertebrate, remains less explored. In this study, we characterized the gut microbial communities of urochordate ascidian (Halocynthia roretzi) across the changes of season and starvation stress using a comprehensive set of omic approaches including 16S rRNA, metagenomic, metabiotic, and transcriptome sequencing.ResultsThe 16S rRNA amplicon profiling revealed that ascidians harbor indigenous gut microbiota distinctly different to the marine microbial community and significant variations in composition and abundance of gut bacteria, with predominant bacterial orders representing each season. Depressed alpha-diversities of gut microbiota were observed across starvation stress when compared with the communities in aquafarm condition. Synechococcales involving photosynthesis and its related biosynthesis was reduced in abundance while the enrichments of Xanthomonadales and Legionellales may facilitate bile acid biosynthesis in starvation stress condition. Meanwhile, the metabolomics analysis found that the long chain fatty acids, linolenic acid, cyanoamino acid, and pigments derived from gut bacteria were upregulated, suggesting a beneficial contribution of the gut microbiome to ascidian under starvation stress.ConclusionsOur results revealed the seasonal variation of ascidian gut microbiota. Furthermore, we found that the defense and energy-associated metabolites derived from gut microbiome were responded to the starvation stress. The data provide insights into understanding the adaptive interplay between the gut microbiome and ascidian host that maintains a beneficial metabolic system across season and starvation stress. The diversity-generating metabolisms from both microbiota and host might lead to the co-evolution and environmental adaptation.

“…In addition, it seems that ascidian gut microorganisms could directly synthesize some plant-type and insect-type hormones, such as salicylic acid, stearidonic acid, juvenile hormone I, podecdysone B, Iloprost, Nicotinamide. Those plant hormones could induce the wound defense against diseases [52,53], and those insect hormones were involved in improving chemical defense and immunity [54][55][56][57]. Whether these phytohormone receptors were presented on the ascidian itself or on other commensal bacteria was still unknown.…”

Section: Discussionmentioning

confidence: 99%

Seasonal Dynamics and Starvation Impact on the Gut Microbiome of Urochordate Ascidian Halocynthia roretzi

Gao²,

Yang

et al. 2020

Preprint

Background Gut microbiota plays important roles in host animal metabolism, homeostasis and environmental adaptation. However, the interplay between the gut microbiome and urochordate ascidian, the most closet relative of vertebrate, remains less explored. In this study, we characterized the gut microbial communities of urochordate ascidian ( Halocynthia roretzi ) across the changes of season and starvation stress using a comprehensive set of omic approaches including 16S rRNA gene amplicon sequencing, shotgun metagenomics, metabolomic profiling, and transcriptome sequencing. Results The 16S rRNA gene amplicon profiling revealed that ascidians harbor indigenous gut microbiota distinctly different to the marine microbial community and significant variations in composition and abundance of gut bacteria, with predominant bacterial orders representing each season. Depressed alpha-diversities of gut microbiota were observed across starvation stress when compared to the communities in aquafarm condition. Synechococcales involving photosynthesis and its related biosynthesis was reduced in abundance while the enrichments of Xanthomonadales and Legionellales may facilitate bile acid biosynthesis during starvation. Metabolomics analysis found that long chain fatty acids, linolenic acid,cyanoamino acid, and pigments derived from gut bacteria were upregulated, suggesting a beneficial contribution of the gut microbiome to the ascidian under starvation stress. Conclusions Our findings revealed seasonal variation of ascidian gut microbiota. Defense and energy-associated metabolites derived from gut microbiome may provide an adaptive interplay between gut microbiome and ascidian host that maintains a beneficial metabolic system across season and starvation stress. The diversity-generating metabolisms from both microbiota and host might lead to the co-evolution and environmental adaptation.