Spontaneously Formed Ratio-Tunable Micro- and Nano-Capsule Coexist System for Precision and on-Demand Fungicide Delivery in Crop Leave.

Multiscale particle size functional pesticide carriers can provide more efficient protection for plants, but this protection is difficult to achieve via single-scale formulation technology. This study presents a novel one-step method for the preparation of lignin-based micro/nanocapsules with controllable proportions within a unified system. This strategy enables the adjustment of the proportion of nanocapsules to between 18.81% and 85.21%. The microcapsules (MCs) vary in diameter from 2 to 3 µm, whereas the nanocapsules (NCs) span from 160 to 220 nm, with an encapsulation efficiency exceeding 90%. An increased proportion of NCs in the system leads to faster release, heightened sensitivity to UV light, and enhanced penetration into the leaves. During Phytophthora capsici (P. capsici) infection, the NCs in the leaves interact with the defensive enzymes of the plant to quickly respond. Moreover, an optimal balance of MCs and NCs is key to effective fungicide use, not just a higher concentration of NCs. A 65:35 ratio of NCs to MCs ensures effective inhibition of P. capsici outside leaves and a rapid response to leaf invasion. This study enhances fungicide efficiency and advances the development of nanoresponsive fungicides to promote sustainable agricultural practices.

Extensive crystal fractionation of high-silica magmas revealed by K isotopes.

Fractional crystallization plays a critical role in generating the differentiated continental crust on Earth. However, whether efficient crystal-melt separation can occur in viscous felsic magmas remains a long-standing debate because of the difficulty in discriminating between differentiated melts and complementary cumulates. Here, we found large (~1 per mil) potassium isotopic variation in 54 strongly peraluminous high-silica (silicon dioxide >70 weight %) leucogranites from the Himalayan orogen, with potassium isotopes correlated with trace elemental proxies (e.g., strontium, rubidium/strontium, and europium anomaly) for plagioclase crystallization. Quantitative modeling requires up to ~60 to 90% fractional crystallization to account for the progressively light potassium isotopic composition of the fractionated leucogranites, while plagioclase accumulation results in enrichment of heavy potassium isotopes in cumulate leucogranites. Our findings strongly support fractional crystallization of high-silica magmas and highlight the great potential of potassium isotopes in studying felsic magma differentiation.

Architecture of the photosynthetic complex from a green sulfur bacterium.

The photosynthetic apparatus of green sulfur bacteria (GSB) contains a peripheral antenna chlorosome, light-harvesting Fenna-Matthews-Olson proteins (FMO), and a reaction center (GsbRC). We used cryo-electron microscopy to determine a 2.7-angstrom structure of the FMO-GsbRC supercomplex from Chlorobaculum tepidum The GsbRC binds considerably fewer (bacterio)chlorophylls [(B)Chls] than other known type I RCs do, and the organization of (B)Chls is similar to that in photosystem II. Two BChl layers in GsbRC are not connected by Chls, as seen in other RCs, but associate with two carotenoid derivatives. Relatively long distances of 22 to 33 angstroms were observed between BChls of FMO and GsbRC, consistent with the inefficient energy transfer between these entities. The structure contains common features of both type I and type II RCs and provides insight into the evolution of photosynthetic RCs.