Rmg8 and Rmg7, wheat genes for resistance to the wheat blast fungus,recognize the same avirulence gene AVR‐Rmg8

Rmg8 and Rmg7 are genes for resistance to the wheat blast fungus (Pyricularia oryzae), located on chromosome 2B in hexaploid wheat and chromosome 2A in tetraploid wheat, respectively. AVR‐Rmg8, an avirulence gene corresponding to Rmg8, was isolated from a wheat blast isolate through a map‐based strategy. The cloned fragment encoded a small protein containing a putative signal peptide. AVR‐Rmg8 was recognized not only by Rmg8, but also by Rmg7, suggesting that these two resistance genes are equivalent to a single gene from the viewpoint of resistance breeding.     

Plasma N-glycome composition associates with chronic low back pain

Background

Low back pain (LBP) is the symptom of a group of syndromes with heterogeneous underlying mechanisms and molecular pathologies, making treatment selection and patient prognosis very challenging. Moreover, symptoms and prognosis of LBP are influenced by age, gender, occupation, habits, and psychological factors. LBP may be characterized by an underlying inflammatory process. Previous studies indicated a connection between inflammatory response and total plasma N-glycosylation. We wanted to identify potential changes in total plasma N-glycosylation pattern connected with chronic low back pain (CLBP), which could give an insight into the pathogenic mechanisms of the disease.

Elevated CO2 and water deficit effects on photosynthesis, ribulose bisphosphate carboxylase‐oxygenase, and carbohydrate metabolism in rice

Rice (Oryza sativa[L.] cv. IR-72) was grown for a season in sunlit, controlled-environment chambers at 350 or 700 µmol CO₂ mol^?1 under continuously flooded (unstressed) or drought-imposed periods at panicle initiation (stressed). The midday canopy photosynthetic rates (P_n), measured at the CO₂ concentration ([CO₂]) used for growth, were enhanced by high [CO₂] but reduced by drought. High [CO₂] increased P_n by 18 to 34% for the unstressed plants, and 6 to 12% for the stressed plants. In the unstressed plants, CO₂ enrichment increased water-use efficiency (WUE) by 26%, and reduced evapotranspiration (ET) by 8 to 14%. Both high [CO₂] and severe drought decreased the activity and content of ribulose bisphosphate carboxylase-oxygenase (Rubisco). High-CO₂-unstressed plants had 6 to 22% smaller content and 5 to 25%, lower activity of Rubisco than ambient-CO₂-unstressed plants. Under severe drought, reductions of Rubisco were 53 and 27% in activity and 40 and 12% in content, respectively, for ambient- and high-CO₂ treatments. The apparent catalytic turnover rate (K_cat) of midday fully activated Rubisco was not altered by high [CO₂], but severe drought reduced K_cat by 17 to 23%. Chloroplasts of the high-CO₂ leaves contained more, and larger starch grains than those of the ambient CO₂ leaves. High [CO₂] did not affect the leaf sucrose content of unstressed plants. In contrast, severe drought reduced the leaf starch and increased the sucrose content in both CO₂ treatments. The activity of leaf sucrose phosphate synthase of unstressed plants was not affected by high [CO₂], whereas that of ambient-CO₂-grown plants was reduced 45% by severe drought. Reduction in ET and enhancements in both P_n and WUE for rice grown under high [CO₂] helped to delay the adverse effects of severe drought and allowed the stressed plants to assimilate CO₂ for an extra day. Thus, rice grown in the next century may utilize less water, use water more efficiently, and be able to tolerate drought better under some situations.     

Strong and stable geographic differentiation of swamp buffalo maternal and paternal lineages indicates domestication in the China/Indochina border region

The swamp type of the Asian water buffalo is assumed to have been domesticated by about 4000 years BP, following the introduction of rice cultivation. Previous localizations of the domestication site were based on mitochondrial DNA (mtDNA) variation within China, accounting only for the maternal lineage. We carried out a comprehensive sampling of China, Taiwan, Vietnam, Laos, Thailand, Nepal and Bangladesh and sequenced the mtDNA Cytochrome b gene and control region and the Y‐chromosomal ZFY, SRY and DBY sequences. Swamp buffalo has a higher diversity of both maternal and paternal lineages than river buffalo, with also a remarkable contrast between a weak phylogeographic structure of river buffalo and a strong geographic differentiation of swamp buffalo. The highest diversity of the swamp buffalo maternal lineages was found in south China and north Indochina on both banks of the Mekong River, while the highest diversity in paternal lineages was in the China/Indochina border region. We propose that domestication in this region was later followed by introgressive capture of wild cows west of the Mekong. Migration to the north followed the Yangtze valley as well as a more eastern route, but also involved translocations of both cows and bulls over large distances with a minor influence of river buffaloes in recent decades. Bayesian analyses of various migration models also supported domestication in the China/Indochina border region. Coalescence analysis yielded consistent estimates for the expansion of the major swamp buffalo haplogroups with a credibility interval of 900 to 3900 years BP. The spatial differentiation of mtDNA and Y‐chromosomal haplotype distributions indicates a lack of gene flow between established populations that is unprecedented in livestock.     

Mouse-adapted SARS-CoV-2 protects animals from lethal SARS-CoV challenge

The emergence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has resulted in a pandemic causing significant damage to public health and the economy. Efforts to understand the mechanisms of Coronavirus Disease 2019 (COVID-19) have been hampered by the lack of robust mouse models. To overcome this barrier, we used a reverse genetic system to generate a mouse-adapted strain of SARS-CoV-2. Incorporating key mutations found in SARS-CoV-2 variants, this model recapitulates critical elements of human infection including viral replication in the lung, immune cell infiltration, and significant in vivo disease. Importantly, mouse adaptation of SARS-CoV-2 does not impair replication in human airway cells and maintains antigenicity similar to human SARS-CoV-2 strains. Coupled with the incorporation of mutations found in variants of concern, CMA3p20 offers several advantages over other mouse-adapted SARS-CoV-2 strains. Using this model, we demonstrate that SARS-CoV-2–infected mice are protected from lethal challenge with the original Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), suggesting immunity from heterologous Coronavirus (CoV) strains. Together, the results highlight the use of this mouse model for further study of SARS-CoV-2 infection and disease.

Studying cross-protection from different coronaviruses is important to inform the research for a universal vaccine. This study uses a mouse-adapted SARS-CoV-2 strain to show that it confers protection from SARS-CoV challenge, suggesting possible immunity from heterologous challenge following natural infection.     

Ecological divergence of <Emphasis Type="Italic">Chaetopteryx rugulosa</Emphasis> species complex (Insecta,Trichoptera) linked to climatic niche diversification

Climate change may affect species diversity and, consequently, ecological processes such as leaf decomposition. We evaluated the effects of increased temperature and carbon dioxide (CO₂) on fungal biomass, leaf breakdown, and on survival and growth of the shredder Phylloicus elektoros. We hypothesized that climatic changes would result in lower survival and growth of shredders and lower leaf consumption by these organisms. On the other hand, we predicted an increase in fungal biomass in response to climatic changes. We conducted an experiment in Manaus, Brazil, using four microcosms that simulate real-time air temperature and CO₂ (control chamber), as well as three other chambers subjected to fixed increases in temperature and CO₂ as compared to the control chamber. The “extreme” condition represented an increase of ~4.5°C in temperature and ~870 ppm in CO₂ in relation to the control chamber. Total and shredder leaf-breakdown rates, fungal biomass, and shredder survival rates were significantly lower in warmer and CO₂ concentrated atmospheres. Shredder growth rate and leaf breakdown by microorganisms were similar among all climatic conditions. With climatic changes, we found an increase in the relative importance of microorganisms on leaf-breakdown rates as compared to shredders. Thus, lower leaf breakdown and a change in the main decomposer due to future climatic conditions may result in major changes in the pathways of organic matter processing and, consequently, in aquatic food webs.     

Low-molecular-weight compounds with anticoagulant activity from the scorpion <Emphasis Type="Italic">Heterometrus laoticus</Emphasis> venom

Low-molecular-weight compounds with anticoagulant activity were isolated from the scorpion Heterometrus laoticus venom. The determination of the structure of the isolated compounds by nuclear magnetic resonance and mass spectrometry showed that one of the isolated compounds is adenosine, and the other two are dipeptides leucyl-tryptophan and isoleucyl-tryptophan. The anticoagulant properties of adenosine, which is an inhibitor of platelet aggregation, is well known, but its presence in scorpion venom is shown for the first time. The ability of leucyl-tryptophan and isoleucyl-tryptophan to slow down blood clotting and their presence in scorpion venom are also established for the first time.