Spider silks are among the toughest known materials and thus provide models for renewable, biodegradable, and sustainable biopolymers. However, the entirety of their diversity still remains elusive, and silks that exceed the performance limits of industrial fibers are constantly being found. We obtained transcriptome assemblies from 1098 species of spiders to comprehensively catalog silk gene sequences and measured the mechanical, thermal, structural, and hydration properties of the dragline silks of 446 species. The combination of these silk protein genotype-phenotype data revealed essential contributions of multicomponent structures with major ampullate spidroin 1 to 3 paralogs in high-performance dragline silks and numerous amino acid motifs contributing to each of the measured properties. We hope that our global sampling, comprehensive testing, integrated analysis, and open data will provide a solid starting point for future biomaterial designs.

The delivery of genetic material into plants has been historically challenging due to the cell wall barrier, which blocks the passage of many biomolecules. Carbon nanotube-based delivery has emerged as a promising solution to this problem and has been shown to effectively deliver DNA and RNA into intact plants. Mitochondria are important targets due to their influence on agronomic traits, but delivery into this organelle has been limited to low efficiencies, restricting their potential in genetic engineering. This work describes the use of a carbon nanotube-polymer hybrid modified with functional peptides to deliver DNA into intact plant mitochondria with almost 30 times higher efficiency than existing methods. Genetic integration of a folate pathway gene in the mitochondria displays enhanced plant growth rates, suggesting its applications in metabolic engineering and the establishment of stable transformation in mitochondrial genomes. Furthermore, the flexibility of the polymer layer will also allow for the conjugation of other peptides and cargo targeting other organelles for broad applications in plant bioengineering.

Genetic engineering of economically important traits in plants is an effective way to improve global welfare. However, introducing foreign DNA molecules into plant genomes to create genetically engineered plants not only requires a lengthy testing period and high developmental costs but also is not well-accepted by the public due to safety concerns about its effects on human and animal health and the environment. Here, we present a high-throughput nucleic acids delivery platform for plants using peptide nanocarriers applied to the leaf surface by spraying. The translocation of sub-micrometer-scale nucleic acid/peptide complexes upon spraying varied depending on the physicochemical characteristics of the peptides and was controlled by a stomata-dependent-uptake mechanism in plant cells. We observed efficient delivery of DNA molecules into plants using cell-penetrating peptide (CPP)-based foliar spraying. Moreover, using foliar spraying, we successfully performed gene silencing by introducing small interfering RNA molecules in plant nuclei via siRNA-CPP complexes and, more importantly, in chloroplasts via our CPP/chloroplast-targeting peptide-mediated delivery system. This technology enables effective nontransgenic engineering of economically important plant traits in agricultural systems.

Polypeptides inspired by the natural functional and structural proteins present in living systems are promising materials for various fields in terms of their versatile functionality and physical properties. Designing and synthesizing mimetic sequences of specific peptide motifs in proteins are important for exploring the functionality of natural proteins. Chemoenzymatic polymerization, which utilizes aminolysis (i.e., the reverse reaction of hydrolysis catalyzed by proteases), is a useful technique for synthesizing artificial polypeptide materials and has several advantages, including facile synthesis protocols, environmental friendliness, scalability, and atom economy. In this review, recent progress in chemoenzymatic polypeptide synthesis for the production of functional and structural materials for various applications is summarized in conjunction with the current status of technical challenges in the field.