Chemosynthetic symbioses are partnerships between invertebrate animals and chemosynthetic bacteria. The latter are the primary producers, providing most of the organic carbon needed for the animal host's nutrition. We sequenced genomes of the chemosynthetic symbionts from the lucinid bivalve Loripes lucinalis and the stilbonematid nematode Laxus oneistus. The symbionts of both host species encoded nitrogen fixation genes. This is remarkable as no marine chemosynthetic symbiont was previously known to be capable of nitrogen fixation. We detected nitrogenase expression by the symbionts of lucinid clams at the transcriptomic and proteomic level. Mean stable nitrogen isotope values of Loripes lucinalis were within the range expected for fixed atmospheric nitrogen, further suggesting active nitrogen fixation by the symbionts. The ability to fix nitrogen may be widespread among chemosynthetic symbioses in oligotrophic habitats, where nitrogen availability often limits primary productivity.
Maize ( L.), a key staple crop in Sub-Saharan Africa, is particularly vulnerable to concurrent drought and heat stress, which threatens crop yield and food security. Plant growth-promoting rhizobacteria (PGPR) have shown potential as biofertilizers to enhance plant resilience under such abiotic stresses.
Rubisco, the most prevalent protein on Earth, catalysers both a reaction that initiates C carbon fixation, and a reaction that initiates photorespiration, which stimulates protein synthesis. Regulation of the balance between these reactions under atmospheric CO fluctuations remains poorly understood. We have hypothesised that vascular plants maintain organic carbon-to-nitrogen homoeostasis by adjusting the relative activities of magnesium and manganese in chloroplasts to balance carbon fixation and nitrate assimilation rates.
National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
Symbiotic nitrogen fixation (SNF) provides nitrogen for soybean. A primary challenge in enhancing yield through efficient SNF lies in striking a balance between its high energy consumption and plant growth. However, the systemic transcriptional reprogramming during nodulation remains limited.
Photocatalytic nitrogen (N2) fixation over semiconductors has always suffered from poor conversion efficiency owing to weak N2 adsorption and the difficulty of N≡N triple bond dissociation. Herein, a Co single-atom catalyst (SAC) model with a C-defect-evoked CoP4 distorted configuration was fabricated using a selective phosphidation strategy, wherein P-doping and C defects co-regulate the local electronic structure of Co sites. Comprehensive experiments and theoretical calculations revealed that the distorted CoP4 configuration caused a strong charge redistribution between the Co atoms and adjacent C atoms, minimizing their electronegativity difference.
Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Madrid, Spain.
During the establishment of the symbiosis with legume plants, rhizobia are exposed to hostile physical and chemical microenvironments to which adaptations are required. Stress response proteins including small heat shock proteins (sHSPs) were previously shown to be differentially regulated in bacteroids induced by bv. viciae UPM791 in different hosts.
