编译|李言

Nature,17 July 2025,Volume 643 Issue 8072 

《自然》，2025年7月17日，第643卷，8072期

天文学Astronomy

Close-in planet induces flares on its host star

近距离行星在主星上引起耀斑

▲ 作者：Ekaterina Ilin, Harish K. Vedantham et al.

▲链接：

https://www.nature.com/articles/s41586-025-09236-z

▲摘要：

该研究报道了拥有两颗已知近轨行星的1700万年的G型矮星在HIP 67522恒星上探测到的行星诱发耀斑现象。

通过结合凌日系外行星巡天卫星的太空光度测量数据及特征化系外行星望远镜历时5年的专项观测，发现该恒星的15次耀斑爆发最内层行星凌日相位附近集中出现，表明该系统中存在持续的磁星—行星相互作用。这种相互作用的稳定性意味着，最内层行星持续承受着比没有相互作用时高出六倍的耀斑速率。

随后，高能辐射与粒子流持续轰击HIP 67522 b行星，这可能解释了詹姆斯·韦伯太空望远镜近期探测到的该行星大气层的异常膨胀。因此，HIP 67522系统堪称研究磁星—行星相互作用对新生系外行星大气影响的典型范例。

▲ Abstract：

Here we report the detection of planet-induced flares on HIP 67522, a 17 million-year-old G dwarf star with two known close-in planets. Combining space-borne photometry from the Transiting Exoplanet Survey Satellite and dedicated Characterising Exoplanets Telescope observations over 5?years, we find that the 15 flares in HIP 67522 cluster near the transit phase of the innermost planet, indicating persistent magnetic star–planet interaction in the system. The stability of interaction implies that the innermost planet is continuously self-inflicting a six times higher flare rate than it would experience without interaction. The subsequent flux of energetic radiation and particles bombarding HIP 67522 b may explain the remarkably extended atmosphere of the planet, recently detected with the James Webb Space Telescope. HIP 67522 is, therefore, an archetype to understand the impact of magnetic star–planet interaction on the atmospheres of nascent exoplanets.

Refractory solid condensation detected in an embedded protoplanetary disk

在原行星盘内部探测到难熔固态物质凝结

▲ 作者：M. K. McClure, Merel van’t Hoff et al.

▲链接：

https://www.nature.com/articles/s41586-025-09163-z

▲摘要：

研究首次观测到行星系统诞生的'零时刻'，捕捉到一个新生行星系统诞生的初始状态。

通过詹姆斯·韦伯太空望远镜和阿塔卡马大型毫米波阵列对年轻原恒星HOPS-315进行红外与毫米波联合观测，研究发现其2.2天文单位内的星盘大气层底部存在温暖的氧化硅气体与结晶硅酸盐矿物储层，该区域与毫米波观测到的氧化硅喷流在空间上完全隔离。

通过与快速颗粒生长凝结模型及星盘结构模型的对比，表明此处形成的难熔固态物质与太阳系内同类物质具有相似性。研究结果表明，星盘内缘区域的物质环境受到星际固态物质升华作用支配，随后从该气体储层中再凝结形成的难熔固体物质，其时间尺度与太阳系内难熔物质凝结过程相当。

▲ Abstract：

Here we report the astronomical detection of this t?=?0 moment, capturing the building blocks of a new planetary system beginning its assembly. The young protostar HOPS-315 is observed at infrared and millimetre wavelengths with the James Webb Space Telescope (JWST) and the Atacama Large Millimeter Array (ALMA), revealing a reservoir of warm silicon monoxide gas and crystalline silicate minerals low in the atmosphere of a disk within 2.2?AU of the star, physically isolated from the millimetre SiO jet. Comparison with condensation models with rapid grain growth and disk structure models suggests the formation of refractory solids analogous to those in our Solar System. Our results indicate that the environment in the inner disk region is influenced by sublimation of interstellar solids and subsequent refractory solid recondensation from this gas reservoir on timescales comparable with refractory condensation in our own Solar System.

化学Chemistry

Electricity-driven enzymatic dynamic kinetic oxidation

电驱动酶的动态动力学氧化

▲ 作者：Beibei Zhao, Yuanyuan Xu et al.

▲链接：

https://www.nature.com/articles/s41586-025-09178-6

▲摘要：

该研究用二茂铁介导的电催化重塑硫胺素依赖酶，实现了α-支化醛的非天然动态动力学氧化。这种强大的电酶催化方法能低至0.05 mol%的酶负载量在全细胞体系中应用，并高效合成多种生物活性（S）-脯氨酸，对映体过量值高达99%。

机理研究表明，该电酶系统具有精确底物识别、加速外消旋化以及促进动力学匹配的电子转移过程的多重功能。

▲ Abstract：

Here we report the reshaping of thiamine-dependent enzymes with ferrocene-mediated electrocatalysis to unlock an unnatural dynamic kinetic oxidation of α-branched aldehydes. This robust electroenzymatic approach yields various bioactive (S)-profens with up to 99% enantiomeric excess; it is applicable with whole cells overexpressing the enzyme and using down to 0.05?mol% enzyme loadings. Mechanistic investigations show multiple functions of the electroenzyme in precise substrate discrimination, accelerating racemization and facilitating kinetically matched electron transfer events.

地球科学Earth Science

Global terrestrial nitrogen fixation and its modification by agriculture

全球陆地生态系统氮固定及其农业活动影响

▲ 作者：Carla R. Reis Ely, Steven S. Perakis et al.

▲链接：

https://www.nature.com/articles/s41586-025-09201-w

▲摘要：

研究揭示了不确定性部分源于采样偏差——现有自然陆地生态系统的生物固氮（BNF）测量数据多来自固氮生物丰度达全球平均水平17倍的区域。为校正偏差，研究人员通过空间显式尺度转换方法，基于主要生物地球化学固氮生态位分布对实地测量数据进行升尺度估算，获得全球陆地BNF新估值。

研究发现自然生物群落的BNF总量为65?(52–77)?Tg?N?yr^?1，低于既往自下而上的经验估计，其中热带森林和旱地贡献主要份额；农田和人工草场的农业BNF高达56（54-58）Tg?N?yr^?1。

与工业化前相比，农业BNF已使陆地BNF总量提升64%，陆地总氮输入量增加60%。研究表明，BNF在自然生物群落中可能对碳汇形成更强约束，并且代表农业氮源在全球氮循环中的贡献被普遍低估，同时现行氮素安全使用限值的设定需重新考量。

▲ Abstract：

Here we show that this uncertainty is partly because of sampling bias, as field BNF measurements in natural terrestrial ecosystems occur where N fixers are 17 times more prevalent than their mean abundances worldwide. To correct this bias, we develop new estimates of global terrestrial BNF by upscaling field BNF measurements using spatially explicit abundances of all major biogeochemical N-fixing niches. We find that natural biomes sustain lower BNF, 65?(52–77)?Tg?N?yr^?1, than previous empirical bottom-up estimates, with most BNF occurring in tropical forests and drylands. We also find high agricultural BNF in croplands and cultivated pastures, 56?(54–58)?Tg?N?yr^?1. Agricultural BNF has increased terrestrial BNF by 64% and total terrestrial N inputs from all sources by 60% over pre-industrial levels. Our results indicate that BNF may impose stronger constraints on the carbon sink in natural terrestrial biomes and represent a larger source of agricultural N than is generally considered in analyses of the global N cycle, with implications for proposed safe operating limits for N use.

生物学Biology

Eighteen million years of diverse enamel proteomes from the East African Rift

来自东非大裂谷1800万年前的牙釉质蛋白质组多样性研究

▲ 作者：Daniel R. Green, Kevin T. Uno et al.

▲链接：

https://www.nature.com/articles/s41586-025-09040-9

▲摘要：

研究人员在保存了丰富新生代哺乳动物演化记录的肯尼亚图尔卡纳盆地，采集了从更新世到渐新世古生物遗址化石牙釉质内部的微量蛋白质组。

通过基于质谱的蛋白质组学工作流程，并采用特定标准定位源自牙釉质的成岩修饰片段，研究人员成功从早中新世犀科化石和若干长鼻目化石中，复原了釉原蛋白、成釉蛋白、基质金属蛋白酶-20和牙本质基质酸性磷蛋白1的片段。成岩修饰片段数量随化石年代增加而递减，且早中新世不同遗址的保存状况存在显著差异。

尽管这些序列片段稀疏、鉴定存在不确定性且可能发生成岩序列改变，但系统发育分析表明其对已灭绝类群的分类定位具有重要贡献。研究鉴定出支持这些蛋白质古老年龄的典型修饰特征，包括迄今已知最古老的晚期糖基化终产物实例。

在地球持续高温区域之一的致密牙釉质组织中发现蛋白质序列，预示着可能发现更古老的蛋白质组，这将为研究已灭绝类群的古生物学特征和演化关系提供关键分子证据。

▲ Abstract：

Here we sample small proteomes from the interior enamel of fossils at palaeontological sites from the Pleistocene to the Oligocene in the Turkana Basin, Kenya, which has produced a rich record of Cenozoic mammalian evolution10. Through a mass-spectrometry-based proteomic workflow, and using criteria to locate diagenetiforms derived from enamel, we recover fragments of enamelin, ameloblastin, matrix metalloprotease-20 and dentin matrix acidic phosphoprotein?1 from an Early Miocene rhinocerotid and several proboscideans collected from the sites of Buluk (16?million years ago; Ma) and Loperot (18?Ma). Diagenetiform counts decline in progressively older fossils, and we observe variability in Early Miocene preservation across sites. Phylogenetic analyses reveal the contribution of these sequences to the systematic placement of extinct taxa, although we caution that this approach must account for sparse fragments, uncertainty in fragment identification and possible sequence diagenesis. We identify likely modifications that support the ancient age of these proteins, and some of the oldest examples of advanced glycation end-products yet known. The discovery of protein sequences within dense enamel tissues in one of the persistently warmest regions on Earth promises the discovery of much older proteomes that will aid in the study of the palaeobiology and evolutionary relationships of extinct taxa.

Motor learning refines thalamic influence on motor cortex

运动学习细化丘脑对运动皮层的调控作用

▲ 作者：Assaf Ramot, Felix H. Taschbach et al.

▲链接：

https://www.nature.com/articles/s41586-025-08962-8

▲摘要：

通过使用纵向成像技术追踪小鼠初级运动皮层（M1）第2/3层的主要输入来源，研究发现运动丘脑是编码熟练动作（两周动物训练）的关键输入枢纽。

利用光遗传学技术，研究人员鉴定出学习前后均受丘脑输入强驱动的M1第2/3层神经元亚群。研究发现，运动学习可重塑丘脑对M1的调控模式，使运动丘脑优先激活编码熟练动作的M1神经元。抑制熟练期丘脑向M1的输入会显著破坏习得动作的执行。该研究揭示了运动学习通过重构丘脑-M1神经环路实现熟练动作的稳定执行。

▲ Abstract：

Here, using longitudinal axonal imaging of the main inputs to M1 L2/3 in mice, we show that the motor thalamus is the key input source that encodes learned movements in experts (animals trained for two weeks). We then use optogenetics to identify the subset of M1 L2/3 neurons that are strongly driven by thalamic inputs before and after learning. We find that the thalamic influence on M1 changes with learning, such that the motor thalamus preferentially activates the M1 neurons that encode learned movements in experts. Inactivation of the thalamic inputs to M1 in experts impairs learned movements. Our study shows that motor learning reshapes the thalamic influence on M1 to enable the reliable execution of learned movements.