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Insect legs play a crucial role in various modes of locomotion, including walking, jumping, swimming, and other forms of movement. The flexibility of their leg joints is critical in enabling various modes of locomotion. The frog‐legged leaf beetle Sagra femorata possesses remarkably enlarged hind legs, which are considered to be a critical adaptation that enables the species to withstand external pressures. When confronted with external threats, S. femorata initiates a stress response by rapidly rotating its hind legs backward and upward to a specific angle, thereby potentially intimidating potential assailants. Based on video analysis, we identified 4 distinct phases of the hind leg rotation process in S. femorata, which were determined by the range of rotation angles (0°−168.77°). Utilizing micro‐computed tomography (micro‐CT) technology, we performed a 3‐dimensional (3D) reconstruction and conducted relative positioning and volumetric analysis of the metacoxa and metatrochanter of S. femorata. Our analysis revealed that the metacoxa–trochanter joint is a “screw‐nut” structure connected by 4 muscles, which regulate the rotation of the legs. Further testing using a 3D‐printed model of the metacoxa–trochanter joint demonstrated its possession of a self‐locking mechanism capable of securing the legs in specific positions to prevent excessive rotation and dislocation. It can be envisioned that this self‐locking mechanism holds potential for application in bio‐inspired robotics. [ABSTRACT FROM AUTHOR]

Nitrogen‐fixing root nodules are formed by symbiotic association of legume hosts with rhizobia in nitrogen‐deprived soils. Successful symbiosis is regulated by signals from both legume hosts and their rhizobial partners. HmuS is a heme degrading factor widely distributed in bacteria, but little is known about the role of rhizobial hmuS in symbiosis with legumes. Here, we found that inactivation of hmuSpSym in the symbiotic plasmid of Mesorhizobium amorphae CCNWGS0123 disrupted rhizobial infection, primordium formation, and nitrogen fixation in symbiosis with Robinia pseudoacacia. Although there was no difference in bacteroids differentiation, infected plant cells were shrunken and bacteroids were disintegrated in nodules of plants infected by the ΔhmuSpSym mutant strain. The balance of defence reaction was also impaired in ΔhmuSpSym strain‐infected root nodules. hmuSpSym was strongly expressed in the nitrogen‐fixation zone of mature nodules. Furthermore, the HmuSpSym protein could bind to heme but not degrade it. Inactivation of hmuSpSym led to significantly decreased expression levels of oxygen‐sensing related genes in nodules. In summary, hmuSpSym of M. amorphae CCNWGS0123 plays an essential role in nodule development and maintenance of bacteroid survival within R. pseudoacacia cells, possibly through heme‐binding in symbiosis. Summary Statement: We characterize the hmuSpSym gene located in the symbiotic plasmid of Mesorhizobium amorphae CCNWGS0123 that participates in symbiosis with Robinia pseudoacacia. Inactivation of hmuSpSym underpins damaged symbiotic phenotypes and necrotic bacteroids, which potentially affects symbiosis via HmuSpSym as a heme‐binding factor. [ABSTRACT FROM AUTHOR]

The microbiomes of rhizocompartments (nodule endophytes, root endophytes, rhizosphere and root zone) in soya bean and alfalfa were analysed using high-throughput sequencing to investigate the interactions among legume species, microorganisms and soil types. A clear hierarchical filtration of microbiota by plants was observed in the four rhizocompartments - the nodule endosphere, root endosphere, rhizosphere and root zone - as demonstrated by significant variations in the composition of the microbial community in the different compartments. The rhizosphere and root zone microbial communities were largely influenced by soil type, and the nodule and root endophytes were primarily determined by plant species. Diverse microbes inhabited the root nodule endosphere, and the corresponding dominant symbiotic rhizobia belonged to Ensifer for alfalfa and Ensifer- Bradyrhizobium for soya bean. The nonsymbiotic nodule endophytes were mainly Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes. The variation in root microbial communities was also affected by the plant growth stage. In summary, this study demonstrated that the enrichment process of nodule endophytes follows a hierarchical filtration and that the bacterial communities in nodule endophytes vary according to the plant species. [ABSTRACT FROM AUTHOR]

Enantioselective Michael addition of oxazolones to in situ generated vinylogous imine intermediates is reported. A series of optically active 3-alkylindole derivatives with adjacent quaternary and tertiary stereocenters was obtained. The resulting adducts can readily be converted into syn-configured α,β-disubstituted tryptophan derivatives without compromising the stereoselectivities. [ABSTRACT FROM AUTHOR]

An organocatalytic asymmetric vinylogous Michael addition of dicyanoolefins to vinylogous imine intermediates generated in situ from arenesulfonylalkylindoles has been developed. This protocol provides an easy and convenient approach to C-3 alkyl-substituted indole derivatives with high yields (up to 93%), diastereomeric ratios (up to 99:1 dr) and enantioselectivities (up to 99% ee). The resulting adducts can be also readily converted to pyrazolo derivatives or α-alkylation products of ketones without any decrease of the diastereoselectivities and enantioselectivities. [ABSTRACT FROM AUTHOR]

In the title compound, C12H8N2O4Se, the Se atom is situated on a twofold rotational axis, so the asymmetric unit contains one half-mol-ecule. In the mol-ecule, the C-Se-C angle is 99.48 (13)°, the two benzene rings are inclined to each other at an angle of 63.8 (1)° and the nitro group is twisted by 15.9 (1)° from the attached benzene ring. In the crystal, mol-ecules are held together through weak C-H⋯O inter-actions, forming a three-dimensional network.