Atmospheric methane is the second most important greenhouse gas after carbon dioxide, and is responsible for about 20% of the global warming effect since pre-industrial times. Rice paddies are the largest anthropogenic methane source and produce 7-17% of atmospheric methane. Warm waterlogged soil and exuded nutrients from rice roots provide ideal conditions for methanogenesis in paddies with annual methane emissions of 25-100-million tonnes. This scenario will be exacerbated by an expansion in rice cultivation needed to meet the escalating demand for food in the coming decades. There is an urgent need to establish sustainable technologies for increasing rice production while reducing methane fluxes from rice paddies. However, ongoing efforts for methane mitigation in rice paddies are mainly based on farming practices and measures that are difficult to implement. Despite proposed strategies to increase rice productivity and reduce methane emissions, no high-starch low-methane-emission rice has been developed. Here we show that the addition of a single transcription factor gene, barley SUSIBA2 (refs 7, 8), conferred a shift of carbon flux to SUSIBA2 rice, favouring the allocation of photosynthates to aboveground biomass over allocation to roots. The altered allocation resulted in an increased biomass and starch content in the seeds and stems, and suppressed methanogenesis, possibly through a reduction in root exudates. Three-year field trials in China demonstrated that the cultivation of SUSIBA2 rice was associated with a significant reduction in methane emissions and a decrease in rhizospheric methanogen levels. SUSIBA2 rice offers a sustainable means of providing increased starch content for food production while reducing greenhouse gas emissions from rice cultivation. Approaches to increase rice productivity and reduce methane emissions as seen in SUSIBA2 rice may be particularly beneficial in a future climate with rising temperatures resulting in increased methane emissions from paddies.

Background Secreted effector proteins play critical roles in plant-fungal interactions. The Magnaporthe oryzae genome encodes a large number of secreted proteins. However, the function of majority of M. oryzae secreted proteins remain to be characterized. We previously identified 851 in planta-expressed M. oryzae genes encoding putative secreted proteins, and characterized five M. oryzae cell death–inducing proteins MoCDIP1 to MoCDIP5. In the present study, we expand our work on identification of novel MoCDIP proteins. Results We performed transient expression assay of 98 more in planta-expressed M. oryzae putative secreted protein genes, and identified eight novel proteins, MoCDIP6 to MoCDIP13, that induced plant cell death. Yeast secretion assay and truncation expression analysis revealed that the signal peptides that led the secretion of proteins to the extracellular space, were required for cell death inducing activity of the novel MoCDIPs except for MoCDIP8. Exogenous treatment of rice seedlings with recombinant MoCDIP6 or MoCDIP7 resulted in enhanced resistance to blast fungus, indicating that the two MoCDIPs trigger cell death and elicit defense responses in rice. Conclusions The newly identified MoCDIP6 to MoCDIP13, together with previously identified MoCDIP1 to MoCDIP5, provide valuable targets for further dissection of the molecular mechanisms underlying the rice-blast fungus interaction. Electronic supplementary material The online version of this article (10.1186/s12284-019-0312-z) contains supplementary material, which is available to authorized users.

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Early and effective identification of severe COVID-19 may allow us to improve the outcomes of associated severe acute respiratory illness with fever and respiratory symptoms. Some heat shock proteins (Hsps) are released during oxidative stress, cytotoxic injury, and viral infection and behave as danger-associated molecular patterns (DAMPs).