The involvement of AtMKK1 and AtMKK3 in plant-deleterious microbial volatile compounds-induced defense responses.

KEY MESSAGE: Plant-deleterious microbial volatiles activate the transactivation of hypoxia, MAMPs and wound responsive genes in Arabidopsis thaliana. AtMKK1 and AtMKK3 are involved in the plant-deleterious microbial volatiles-induced defense responses. Microbial volatile compounds (mVCs) are a collection of volatile metabolites from microorganisms with biological effects on all living organisms. mVCs function as gaseous modulators of plant growth and plant health. In this study, the defense events induced by plant-deleterious mVCs were investigated. Enterobacter aerogenes VCs lead to growth inhibition and immune responses in Arabidopsis thaliana. E. aerogenes VCs negatively regulate auxin response and transport gene expression in the root tip, as evidenced by decreased expression of DR5::GFP, PIN3::PIN3-GFP and PIN4::PIN4-GFP. Data from transcriptional analysis suggests that E. aerogenes VCs trigger hypoxia response, innate immune responses and metabolic processes. In addition, the transcript levels of the genes involved in the synthetic pathways of antimicrobial metabolites camalexin and coumarin are increased after the E. aerogenes VCs exposure. Moreover, we demonstrate that MKK1 serves as a regulator of camalexin biosynthesis gene expression in response to E. aerogenes VCs, while MKK3 is the regulator of coumarin biosynthesis gene expression. Additionally, MKK1 and MKK3 mediate the E. aerogenes VCs-induced callose deposition. Collectively, these studies provide molecular insights into immune responses by plant-deleterious mVCs.

[Research on the Evaluation Method and Application of Provincial Differentiated Carbon Peaking in China].

Promoting regions with favorable conditions to take the lead in reaching a carbon peak is an inevitable step towards achieving the dual carbon goals under the "nationwide coordinated action" plan. Considering the differences among Chinese provinces, this study measured the peaking pressure of each province based on the spatial distribution of carbon emissions. We then constructed a provincial peaking capacity evaluation system based on five dimensions, namely, peaking pressure, emission reduction status, economic development, policy support, and resource endowment, to comprehensively evaluate the carbon peaking capacity of 30 provincial administrative regions in China, excluding Hong Kong, Macau, Taiwan, and Tibet, using the entropy value method to determine the index weights. The 30 provinces were divided into five peaking tiers according to the evaluation results. The results showed that:① 18 regions, such as Hainan and Beijing, displayed a surplus in carbon emission space; eight regions, including Hebei and Shandong, showed a deficit in carbon emission space; and the carbon emission spaces allocated to Zhejiang, Anhui, Henan, and Hubei were comparable to their respective actual emissions. ② Developed regions generally had a higher carbon peaking capacity than that of less developed regions, with Beijing and Shanghai showing outstanding carbon peaking capacity, whereas Jiangxi and Guizhou had more room to improve their capacity. Finally, differentiated peaking targets and priority actions were proposed according to the provinces' different peaking tiers and local conditions.

Metabolic fingerprinting unveils quinoa oil as a source of bioactive phytochemicals.

Quinoa is a pseudo-cereal with high phytochemical contents with proven biological and nutritional significance. In recent decades several breeding programmes have introduced new and traditional quinoa varieties to North America and other non-traditional quinoa regions, raising questions regarding variability in their secondary metabolite profiles. In this work, we have fingerprinted 28 quinoa varieties cultivated in Washington State, focussing on the poorly investigated oil fraction. We found variability in both phenolics and carotenoid contents, which is reflected in different antioxidant capacities, as measured by FRAP and DPPH. Fatty acid profiles show significant differences in palmitic acid and long-chain fatty acids. Finally, conspicuous amounts of phytosterols and squalene were found. Through factor analysis, we classified the quinoa varieties into two groups: a first comprising varieties with higher phytochemical and PUFA contents and a second group, with higher linolenic and long-chain fatty acid contents. Both groups may be suitable for potential food applications.