A novel bivalent chromatin associates with rapid induction of camalexin biosynthesis genes in response to a pathogen signal in .

Temporal dynamics of gene expression underpin responses to internal and environmental stimuli. In eukaryotes, regulation of gene induction includes changing chromatin states at target genes and recruiting the transcriptional machinery that includes transcription factors. As one of the most potent defense compounds in , camalexin can be rapidly induced by bacterial and fungal infections.

Polymerase-guided base editing enables in vivo mutagenesis and rapid protein engineering.

Random mutagenesis is a technique used to generate diversity and engineer biological systems. In vivo random mutagenesis generates diversity directly in a host organism, enabling applications such as lineage tracing, continuous evolution, and protein engineering. Here we describe TRIDENT (TaRgeted In vivo Diversification ENabled by T7 RNAP), a platform for targeted, continual, and inducible diversification at genes of interest at mutation rates one-million fold higher than natural genomic error rates.

Discovery of a previously unknown biosynthetic capacity of naringenin chalcone synthase by heterologous expression of a tomato gene cluster in yeast.

Chalcone synthase (CHS) canonically catalyzes carbon-carbon bond formation through iterative decarboxylative Claisen condensation. Here, we characterize a previously unidentified biosynthetic capability of SlCHS to catalyze nitrogen-carbon bond formation, leading to the production of a hydroxycinnamic acid amide (HCAA) compound. By expressing a putative tomato () gene cluster in yeast (), we elucidate the activity of a pathway consisting of a carboxyl methyltransferase (SlMT2), which methylates the yeast primary metabolite 3-hydroxyanthranilic acid (3-HAA) to form a methyl ester, and a SlCHS, which catalyzes the condensation of 3-HAA methyl ester and -coumaroyl-coenzyme A (CoA) through formation of an amide bond.

Engineering control of bacterial cellulose production using a genetic toolkit and a new cellulose-producing strain.

Bacterial cellulose is a strong and ultrapure form of cellulose produced naturally by several species of the Acetobacteraceae Its high strength, purity, and biocompatibility make it of great interest to materials science; however, precise control of its biosynthesis has remained a challenge for biotechnology. Here we isolate a strain of Komagataeibacter rhaeticus (K. rhaeticus iGEM) that can produce cellulose at high yields, grow in low-nitrogen conditions, and is highly resistant to toxic chemicals.