Rhizobial infection and root nodule formation in legumes require recognition of signal molecules produced by the bacteria and their hosts. Here, we show that rhizobial transfer RNA (tRNA)-derived ...small RNA fragments (tRFs) are signal molecules that modulate host nodulation. Three families of rhizobial tRFs were confirmed to regulate host genes associated with nodule initiation and development through hijacking the host RNA-interference machinery that involves ARGONAUTE 1. Silencing individual tRFs with the use of short tandem target mimics or by overexpressing their targets represses root hair curling and nodule formation, whereas repressing these targets with artificial microRNAs identical to the respective tRFs or mutating these targets with CRISPR-Cas9 promotes nodulation. Our findings thus uncover a bacterial small RNA-mediated mechanism for prokaryote-eukaryote interaction and may pave the way for enhancing nodulation efficiency in legumes.
By examining the ancient and modern educational approaches in the Xinjiang Uyghur Autonomous Region, this study analyzes the changes and processes based on the analysis of Xinjiang’s location, ethnic ...situation, and educational resources and studies the differences between language education in Xinjiang and the general region, which proposes the importance of the popularization of the common national language for language education. It also analyzes the relationship between the common national language and Chinese language education.The paper is divided into four parts. The first part introduces the background. The second part introduces language education under the new curriculum standards and explores in depth through language learning requirements, teaching materials, and school-based resources. The third part analyzes the current situation of the use of national languages by ethnic minorities in Xinjiang and explores it through students, language teachers, and learning. The fourth part concludes. The shift from “bilingual education” to full Chinese language teaching has been a long-standing educational goal in Xinjiang, and it has been achieved. However, the version of language teaching materials in the region lags, the curriculum reform is slow, and teachers and language curriculum resources are relatively scarce. This will provide some reference for future research and exploration of language education in Xinjiang. This study finds that the versions of the language teaching materials lag, the curriculum reform is slow, and the teacher strength and the language curriculum resources are relatively scarce.
Incineration is well used to treat municipal solid wastes (MSW) but is difficult to treat sewage sludge (SS) because it requires a large amount of heat to remove high content of moisture in SS. Over ...50 billion tons of SS are discharged annually in China, and the need for a better waste treatment strategy is urgent. This paper is to introduce a waste disposal technology referring to the integrated treatment of MSW and SS. Four scenarios were analyzed including Mono-incineration of MSW (Case 1) and SS (Case 2), co-incineration of SS and MSW by traditional (Case 3) and integrated ways (Case 4), in terms of environment, energy and economic impact by means of LCA, CED and TEA method. From the environmental perspective, the top four mid-point categories involving the largest effect on four cases are N-C (non-carcinogens), OLD (Ozone layer depletion), TET (Terrestrial eco-toxicity), and GWP (Global warming potential). Case 4 has the most positive effect on climate change and resources (−1.44 kg CO2 eq and −18 MJ, respectively) according to end-point categories. From the view of energy, Case 4 shows the best performance of energy efficiency, and significantly saves the non-renewable energy (0.21 t coal per ton feedstock compared with Case 3). From the economic part, Case 4 is preferentially potential with the best profit, cutting down 79.08% of cost in coal than that in Case 3. These results provide understandings of developing an effective approach for co-treating MSW and SS in the near future.
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•An integrated treatment method of sewage sludge and municipal solid waste was proposed.•Four scenarios were analyzed in terms of environment, energy and economic impact.•The integrated treatment had the most positive contribution to climate change and resources.•The integrated treatment showed best performance of energy efficiency, and significantly saved the non-renewable energy.
Evidence of introgression, the transfer of genetic material, between crops and their wild relatives through spontaneous hybridization and subsequent backcrossing has been documented; however, the ...evolutionary patterns and consequences of introgression and its influence on the processes of crop domestication and varietal diversification are poorly understood.
We investigate the genomic landscape and evolution of putative crop-wild-relative introgression by analyzing the nuclear and chloroplast genomes from a panel of wild (Glycine soja) and domesticated (Glycine max) soybeans. Our data suggest that naturally occurring introgression between wild and domesticated soybeans was widespread and that introgressed variation in both wild and domesticated soybeans was selected against throughout the genomes and preferentially removed from the genomic regions underlying selective sweeps and domestication quantitative trait locus (QTL). In both taxa, putative introgression was preferentially retained in recombination-repressed pericentromeric regions that exhibit lower gene densities, reflecting potential roles of recombination in purging introgression. Despite extensive removal of introgressed variation by recurrent selection for domestication-related QTL and associated genomic regions, spontaneous interspecific hybridization during soybean domestication appear to have contributed to a rapid varietal diversification with high levels of genetic diversity and asymmetric evolution between the nuclear and chloroplast genomes.
This work reveals the evolutionary forces, patterns, and consequences of putative genomic introgression between crops and their wild relatives, and the effects of introgression on the processes of crop domestication and varietal diversification. We envision that interspecific introgression serves as an important mechanism for counteracting the reduction of genetic diversity in domesticated crops, particularly the ones under single domestication.
Trichome initiation in Arabidopsis is regulated by a MYB-bHLH-WD40 (MBW) transcriptional activator complex formed by the R2R3 MYB transcription factor GLABRA1 (GL1), MYB23 or MYB82, the bHLH ...transcription factor GLABRA3 (GL3), ENHANCER OF GLABRA3 (EGL3) or TRANSPARENT TESTA8 (TT8), and the WD40-repeat protein TRANSPARENT TESTA GLABRA1 (TTG1). However, the functions of the rice homologs of the MBW complex proteins remained uncharacterized. Based on amino acid sequence identity and similarity, and protein interaction prediction, we identified OsGL1s, OsGL3s and OsTTG1s as rice homologs of the MBW complex proteins. By using protoplast transfection, we show that OsGL1D, OsGL1E, OsGL3B and OsTTG1A were predominantly localized in the nucleus, OsGL3B functions as a transcriptional activator and is able to interact with GL1 and TTG1. By using yeast two-hybrid and protoplast transfection assays, we show that OsGL3B is able to interact with OsGL1E and OsTTG1A, and OsGL1E and OsTTG1A are also able to interact with GL3. On the other hand, we found that OsGL1D functions as a transcription activator, and it can interact with GL3 but not OsGL3B. Furthermore, our results show that expression of OsTTG1A in the ttg1 mutant restored the phenotypes including alternations in trichome and root hair formation, seed color, mucilage production and anthocyanin biosynthesis, indicating that OsTTG1A and TTG1 may have similar functions. These results suggest that the rice homologs of the Arabidopsis MBW complex proteins are able to form MBW complexes, but may have conserved and non-conserved functions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Social distancing orders have been enacted worldwide to slow the coronavirus disease (COVID-19) pandemic, reduce strain on healthcare systems, and prevent deaths. To estimate the impact of the timing ...and intensity of such measures, we built a mathematical model of COVID-19 transmission that incorporates age-stratified risks and contact patterns and projects numbers of hospitalizations, patients in intensive care units, ventilator needs, and deaths within US cities. Focusing on the Austin metropolitan area of Texas, we found that immediate and extensive social distancing measures were required to ensure that COVID-19 cases did not exceed local hospital capacity by early May 2020. School closures alone hardly changed the epidemic curve. A 2-week delay in implementation was projected to accelerate the timing of peak healthcare needs by 4 weeks and cause a bed shortage in intensive care units. This analysis informed the Stay Home-Work Safe order enacted by Austin on March 24, 2020.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Chitin deacetylase (CDA) can catalyze the deacetylation of chitin to produce chitosan. In this study, we identified and characterized a chitin deacetylase gene from
(
), and a soluble recombinant ...protein chitin deacetylase from
of molecular weight 45 kDa was cloned, expressed, and purified. The full-length cDNA sequence of
CDA-9k was 1068 bp long and encoded 355 amino acid residues that contained the typical domain structure of carbohydrate esterase family 4. The predicted three-dimensional structure of
CDA-9k showed a 67.32% homology with
. Recombinant chitin deacetylase had the highest activity at 40 °C and pH 8.0 in Tris-HCl buffer. The enzyme activity was enhanced by metal ions Co
, Fe
, Ca
, and Na
, while it was inhibited by Zn
, Ba
, Mg
, and EDTA. Molecular simulation of
CDA-9k was conducted based on sequence alignment and homology modeling. The
CDA-9k F18G mutant showed a 1.6-fold higher activity than the wild-type enzyme. In summary, this is the first report of the cloning and heterologous expression of the chitin deacetylase gene in
. The characterization and function study of
CDA-9k will serve as an important reference point for future application.
Allopolyploidization has occurred frequently within the Triticum–Aegilops complex which provides a suitable system to investigate how allopolyploidization shapes the expression patterns of duplicated ...homeologs. We have conducted transcriptome‐profiling of leaves and young inflorescences in wild and domesticated tetraploid wheats, Triticum turgidum ssp. dicoccoides (BBAA) and ssp. durum (BBAA), an extracted tetraploid (BBAA), and a synthetic tetraploid (SˡSˡAA) wheat together with its diploid parents, Aegilops longissima (SˡSˡ) and Triticum urartu (AA). The two diploid species showed tissue‐specific differences in genome‐wide ortholog expression, which plays an important role in transcriptome shock‐mediated homeolog expression rewiring and hence transcriptome asymmetry in the synthetic tetraploid. Further changes of homeolog expression apparently occurred in natural tetraploid wheats, which led to novel transcriptome asymmetry between the two subgenomes. In particular, our results showed that extremely biased homeolog expression can occur rapidly upon the allotetraploidzation and this trend is further enhanced in the course of domestication and evolution of polyploid wheats. Our results suggest that allopolyploidization is accompanied by distinct phases of homeolog expression changes, with parental legacy playing major roles in the immediate rewiring of homeolog expression upon allopolyploidization, while evolution and domestication under allotetraploidy drive further homeolog‐expression changes toward re‐established subgenome expression asymmetry.
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