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Adult neurogenesis in the hippocampus may represent a form of plasticity in brain functions including mood, learning and memory. However, mechanisms underlying neural stem/progenitor cells (NSPCs) proliferation are not well understood. We found that Agrin, a factor critical for neuromuscular junction formation, is elevated in the hippocampus of mice that are stimulated by enriched environment (EE). Genetic deletion of the Agrn gene in excitatory neurons decreases NSPCs proliferation and increases depressive-like behavior. Low-density lipoprotein receptor-related protein 4 (Lrp4), a receptor for Agrin, is expressed in hippocampal NSPCs and its mutation blocked basal as well as EE-induced NSPCs proliferation and maturation of newborn neurons. Finally, we show that Lrp4 interacts with and activates receptor tyrosine kinase-like orphan receptor 2 (Ror2); and Ror2 mutation impairs NSPCs proliferation. Together, these observations identify a role of Agrin-Lrp4-Ror2 signaling for adult neurogenesis, uncovering previously unexpected functions of Agrin and Lrp4 in the brain.

SUMMARY: Gibberellins (GAs) play crucial roles in regulating plant architecture and grain yield of crops. In rice, the inactivation of endogenous bioactive GAs and their precursors by GA 2‐oxidases (GA2oxs) regulates stem elongation and reproductive development. However, the regulatory mechanisms of GA2ox gene expression, especially in rice reproductive organs, are unknown. The BEL1‐like homeodomain protein OsBLH4, a negative regulatory factor for the rice OsGA2ox1 gene, was identified in this study. Loss of OsBLH4 function results in decreased bioactive GA levels and pleiotropic phenotypes, including reduced plant height, decreased grain number per panicle, and delayed heading date, as also observed in OsGA2ox1‐overexpressing plants. Consistent with the mutant phenotype, OsBLH4 was predominantly expressed in shoots and young spikelets; its encoded protein was exclusively localized in the nucleus. Molecular analysis demonstrated that OsBLH4 directly bound to the promoter region of OsGA2ox1 to repress its expression. Genetic assays revealed that OsBLH4 acts upstream of OsGA2ox1 to control rice plant height, grain number, and heading date. Taken together, these results indicate a crucial role for OsBLH4 in regulating rice plant architecture and yield potential via regulation of bioactive GA levels, and provide a potential strategy for genetic improvements of rice. Significance Statement: GA 2‐oxidases (GA2oxs) play crucial roles in regulating plant architecture and yield by inactivating endogenous bioactive GAs and their precursors, but the regulatory mechanisms of GA2ox gene expression remain unclear. This study identifies that OsBLH4, a member of the BEL1‐like homeodomain proteins, acts upstream of OsGA2ox1, modulates endogenous bioactive GA levels, and regulates stem elongation and reproductive development in rice. [ABSTRACT FROM AUTHOR]

Mangroves play a crucial role in improving the water quality of mangrove wetlands. However, current research faces challenges, such as the difficulty in quantifying the impact of mangroves on water quality and the unclear pathways of influence. This study utilized remote sensing imagery to investigate the long-term changes in mangrove forests in the Futian Mangrove National Nature Reserve and constructed a water quality index based on water quality data. Finally, structural equation modeling was employed to explore the pathways of influence and quantify the impact effects of mangroves, climate, and water quality. The study findings revealed several key points: (1) The mangrove forests in the Futian Mangrove National Nature Reserve exhibited a trend of expansion towards the ocean during this period. (2) The seasonal and annual characteristics of water quality in Shenzhen Bay indicated a significant improvement in water quality from 2000 to 2020. (3) Mangroves have significant direct and indirect impacts on water quality, which are more pronounced than the effects of climate factors. These findings not only offer insights for the environmental management and conservation of Shenzhen Bay but also provide support for future comprehensive studies on the response relationships between the morphology, species, and physiological characteristics of mangroves and water quality. [ABSTRACT FROM AUTHOR]

With an increasingly urbanized world, there is an urgent need to examine how cities may evolve and achieve sustainability. This paper systematically looks at the Greater Bay Area (GBA) and the Poyang Lake Region (PLR) in China to examine the spatial processes for insights into cities and urbanization, balancing the environmental and socio‐economic dimensions. A total of 226 805 cells are analyzed to unveil the relationship between sustainability changes in 2015–2019 period and urban form indicators, considering sociodemographic variables, geographical features, and city size as control variables. Two tree‐based machine learning models (Random Forest and XGBoost) are developed. This study provides evidence that a monocentric urban form and a high share of small activity clusters are not good for sustainability. For each urban form indicator, there is a non‐linear relationship with sustainability. The results of the machine learning models reconfirm the sustainability benefits of having a strong second activity cluster comparable to the largest one. When planning cities, some forms of land use buffering are desirable. There is also support for developing relatively large activity nodes and promoting compactness in urban form. Beyond urban form characteristics, the levels of urbanization, economic development, and population are still highly relevant. [ABSTRACT FROM AUTHOR]