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The development of soft electronics requires methods to connect flexible and stretchable circuits. With conventional rigid electronics, vias are typically used to electrically connect circuits with multilayered architectures, increasing device integration and functionality. However, creating vias using soft conductors leads to additional challenges. Here we show that soft vias and planar interconnects can be created through the directed stratification of liquid metal droplets with programmed photocuring. Abnormalities that occur at the edges of a mask during ultraviolet exposure are leveraged to create vertical stair-like architectures of liquid metal droplets within the photoresin. The liquid metal droplets in the uncured (liquid) resin rapidly settle, assemble and then are fully cured, forming electrically conductive soft vias at multiple locations throughout the circuit in a parallel and spatially tunable manner. Our three-dimensional selective stratification method can also form seamless connections with planar interconnects, for in-plane and through-plane electrical integration. 

Strigolactone (SL) is a plant hormone required for plant development. DWARF53 (D53) functions as a transcription repressor in SL signaling. However, the role of D53 in cotton (Gossypium hirsutum, Gh) fiber development remains unclear. Here, we identify that GhD53 suppresses fiber elongation by repressing transcription of GhFAD3 genes, which control linolenic acid (C18:3) biosynthesis. Mechanistically, GhD53 interacts with SL-related transcriptional activate factor (GhSLRF) to prevent its binding on Omega-3 fatty acid desaturase gene (GhFAD3) promoters, thereby inhibiting GhFAD3 transcription. Upon SL exposure, GhD53 is degraded and leads to GhSLRF activation. This activation further promotes GhFAD3 transcription, C18:3 biosynthesis, and fiber elongation. Our findings identify the molecular mechanism of how SL controls cell elongation via D53 and offer potential strategies to improve cotton quality through SL application. 

The starch metabolic network was investigated in relation to other metabolic processes by examining a mutant with altered single-gene expression of ATP citrate lyase (ACL), an enzyme responsible for generating cytosolic acetyl-CoA pool from citrate. Previous research has shown that transgenic antisense plants with reduced ACL activity accumulate abnormally enlarged starch granules. In this study, we explored the underlying molecular mechanisms linking cytosolic acetyl-CoA generation and starch metabolism under short-day photoperiods. We performed transcriptome and quantification of starch accumulation in the leaves of wild-type and antisense seedlings with reduced ACL activity. The antisense-ACLA mutant accumulated more starch than the wild type under short-day conditions. Zymogram analyses were conducted to compare the activities of starch-metabolizing enzymes with transcriptomic changes in the seedling. Differential expression between wild-type and antisense-ACLA plants was detected in genes implicated in starch and acetyl-CoA metabolism, and cell wall metabolism. These analyses revealed a strong correlation between the transcript levels of genes responsible for starch synthesis and degradation, reflecting coordinated regulation at the transcriptomic level. Furthermore, our data provide novel insights into the regulatory links between cytosolic acetyl-CoA metabolism and starch metabolic pathways. 

The elasmoid scales in teleost fish serve as exemplary models for natural fibre composites with integrated flexibility and protection. Yet, limited research has been focused on the potential structural, chemical, and mechanical heterogeneity within individual scales. This study presents systematic characterizations of the elasmoid scales from black drum fish (Pogonias cromis) at different zones within individual scales as a natural fibre composite, focusing on the microscopic structural heterogeneities and corresponding mechanical effects. The focus field at the centre of the scales exhibits a classical tri-layered collagen-based composite design, consisting of the mineralized outermost limiting layer, external elasmodine layer in the middle, and the unmineralized internal elasmodine layer. In comparison, the rostral field at the anterior end of the scales exhibits a two-layered design: the mineralized outermost limiting layer exhibits radii sections on the outer surface, and the inner elasmodine layer consists of collagen fibre-based sublayers with alternating mineralization levels. Chemical and nanoindentation analysis suggests a close correlation between the mineralization levels and the local nanomechanical properties. Comparative finite element modelling shows that the rostral-field scales achieve increased flexibility under both concave and convex bending. Moreover, the evolving geometries of isolated Mandle’s corpuscles in the internal elasmodine layer, transitioning from irregular shapes to faceted octahedrons, suggest the mechanisms of mineral growth and space-filling to thicken the mineralized layers in scales during growth, which enhances the bonding strength between the adjacent collagen fibre layers. This work offers new insights into the structural variations in individual elasmoid scales, providing strategies for bioinspired fibre composite designs with local-adapted functional requirements. 

Abstract The plant cuticle is a complex extracellular lipid barrier that has multiple protective functions. This study investigated cuticle deposition by integrating metabolomics and transcriptomics data gathered from six different maize seedling organs of four genotypes, the inbred lines B73 and Mo17, and their reciprocal hybrids. These datasets captured the developmental transition of the seedling from heterotrophic skotomorphogenic growth to autotrophic photomorphogenic growth, a transition that is highly vulnerable to environmental stresses. Statistical interrogation of these data revealed that the predominant determinant of cuticle composition is seedling organ type, whereas the seedling genotype has a smaller effect on this phenotype. Gene-to-metabolite associations assessed by integrated statistical analyses identified three gene networks associated with the deposition of different elements of the cuticle: cuticular waxes; monomers of lipidized cell wall biopolymers, including cutin and suberin; and both of these elements. These gene networks reveal three metabolic programs that appear to support cuticle deposition, including processes of chloroplast biogenesis, lipid metabolism, and molecular regulation (e.g. transcription factors, post-translational regulators, and phytohormones). This study demonstrates the wider physiological metabolic context that can determine cuticle deposition and lays the groundwork for new targets for modulating the properties of this protective barrier. 

Abstract Auxin, a pivotal regulator of diverse plant growth processes, remains central to development. The auxin-responsive genes auxin/indole-3-acetic acids (AUX/IAAs) are indispensable for auxin signal transduction, which is achieved through intricate interactions with auxin response factors (ARFs). Despite this, the potential of AUX/IAAs to govern the development of the most fundamental biological unit, the single cell, remains unclear. In this study, we harnessed cotton (Gossypium hirsutum) fiber, a classic model for plant single-cell investigation, to determine the complexities of AUX/IAAs. Our research identified 2 pivotal AUX/IAAs, auxin resistant 2 (GhAXR2) and short hypocotyl 2 (GhSHY2), which exhibit opposite control over fiber development. Notably, suppressing GhAXR2 reduced fiber elongation, while silencing GhSHY2 fostered enhanced fiber elongation. Investigating the mechanistic intricacies, we identified specific interactions between GhAXR2 and GhSHY2 with distinct ARFs. GhAXR2's interaction with GhARF6-1 and GhARF23-2 promoted fiber cell development through direct binding to the AuxRE cis-element in the constitutive triple response 1 promoter, resulting in transcriptional inhibition. In contrast, the interaction of GhSHY2 with GhARF7-1 and GhARF19-1 exerted a negative regulatory effect, inhibiting fiber cell growth by activating the transcription of xyloglucan endotransglucosylase/hydrolase 9 and cinnamate-4-hydroxylase. Thus, our study reveals the intricate regulatory networks surrounding GhAXR2 and GhSHY2, elucidating the complex interplay of multiple ARFs in AUX/IAA-mediated fiber cell growth. This work enhances our understanding of single-cell development and has potential implications for advancing plant growth strategies and agricultural enhancements.