Search

● The Green Revolution broadened the trade-off between yield and nitrogen-use efficiency. ● Root developmental and metabolic adaptations to nitrogen availability. ● Mechanisms of nitrogen uptake and assimilation have been extensively studied. ● Modulating plant growth-metabolic coordination improves nitrogen-use efficiency in crops. The Green Revolution of the 1960s boosted crop yields in part through widespread production of semidwarf plant cultivars and extensive use of mineral fertilizers. The beneficial semidwarfism of cereal Green Revolution cultivars is due to the accumulation of plant growth-repressing DELLA proteins, which increases lodging resistance but requires a high-nitrogen fertilizer to obtain high yield. Given that environmentally degrading fertilizer use underpins current worldwide crop production, future agricultural sustainability needs a sustainable Green Revolution through reducing N fertilizer use while boosting grain yield above what is currently achievable. Despite a great deal of research efforts, only a few genes have been demonstrated to improve N-use efficiency in crops. The molecular mechanisms underlying the coordination between plant growth and N metabolism is still not fully understood, thus preventing significant improvement. Recent advances of how plants sense, capture and respond to varying N supply in model plants have shed light on how to improve sustainable productivity in agriculture. This review focuses on the current understanding of root developmental and metabolic adaptations to N availability, and discuss the potential approaches to improve N-use efficiency in high-yielding cereal crops.

Background and Purpose: Because of the absence of effective therapies for metabolic dysfunction‐associated steatohepatitis (MASH), there is a rising interest in fibroblast growth factor 21 (FGF21) analogues due to their potential anti‐fibrotic activities in MASH treatment. PsTag‐FGF21, a long‐acting FGF21 analogue, has demonstrated promising therapeutic effects in several MASH mouse models. However, its efficacy and mechanism against MASH‐related fibrosis remain less well defined, compared with the specific mechanisms through which FGF21 improves glucose and lipid metabolism. Experimental Approach: The effectiveness of PsTag‐FGF21 was evaluated in two MASH‐fibrosis models. Co‐culture systems involving macrophages and hepatic stellate cells (HSCs) were employed for further assessment. Hepatic macrophages were selectively depleted by administering liposome‐encapsulated clodronate via tail vein injections. RNA sequencing and cytokine profiling were conducted to identify key factors involved in macrophage–HSC crosstalk. Key Results: We first demonstrated the significant attenuation of hepatic fibrosis by PsTag‐FGF21 in two MASH‐fibrosis models. Furthermore, we highlighted the crucial role of macrophage phenotypic switch in PsTag‐FGF21‐induced HSC deactivation. FGF21 was demonstrated to regulate macrophages in a PsTag‐FGF21‐like manner. NR4A1, a nuclear factor which is notably down‐regulated in human livers with MASH, was identified as a mediator responsible for PsTag‐FGF21‐induced phenotypic switch. Transcriptional control over insulin‐like growth factor 1, a crucial factor in macrophage–HSC crosstalk, was exerted by the intrinsically disordered region domain of NR4A1. Conclusion and Implications: Our results have elucidated the previously unclear mechanisms through which PsTag‐FGF21 treats MASH‐related fibrosis and identified NR4A1 as a potential therapeutic target for fibrosis. [ABSTRACT FROM AUTHOR]

The laser welding between high strength steel and carbon fiber reinforced polymer (CFRP) was explored in order to improve the mechanical properties and capacity to reflect physical relationships. The influence of process parameters on the mechanical properties of the joint was analyzed by RSM based on the experimental results. A residual regression method was proposed, using the residual block as the core structure and combined it with the fundamental concept and structure of the residual network. The residual regression model with two-layer residual block structure was compared with the RSM model at the same time, and the feasibility of this method was validated by experiments. The results show that the mechanical properties of the hybrid joint increase with the increase of the input laser energy per unit time. The proposed residual regression model can directly characterize the relationship between process parameters, intermediate physical quantities, and shear force and has better prediction accuracy and more physical relationships than RSM. The optimized parameters are laser power 1100 W, welding speed 9 mm/s and defocus distance 15 mm. [ABSTRACT FROM AUTHOR]