ABSTRACT
The shape of a plant's root system influences its ability to reach essential nutrients in the soil and to acquire water during drought. Progress in engineering plant roots to optimize water and nutrient acquisition has been limited by our capacity to design and build genetic programs that alter root growth in a predictable manner. We developed a collection of synthetic transcriptional regulators for plants that can be compiled to create genetic circuits. These circuits control gene expression by performing Boolean logic operations and can be used to predictably alter root structure. This work demonstrates the potential of synthetic genetic circuits to control gene expression across tissues and reprogram plant growth.
Subject(s)
Gene Expression Regulation, Plant , Gene Regulatory Networks , Genes, Synthetic , Plant Roots , Plant Roots/genetics , Plant Roots/growth & development , Soil , Water/metabolismABSTRACT
Homologous recombination (HR) typically occurs during meiosis between homologs, at a few unplanned locations along the chromosomes. In this study, we tested whether targeted recombination between homologous chromosomes can be achieved via Clustered Regulatory Interspaced Short Palindromic Repeat associated protein Cas9 (CRISPR-Cas9)-induced DNA double-strand break (DSB) repair in Arabidopsis thaliana. Our experimental system includes targets for DSB induction in euchromatic and heterochromatic genomic regions of hybrid F1 plants, in one or both parental chromosomes, using phenotypic and molecular markers to measure Non-Homologous End Joining and HR repair. We present a series of evidence showing that targeted DSBs can be repaired via HR using a homologous chromosome as the template in various chromatin contexts including in pericentric regions. Targeted crossover was rare, but gene conversion events were the most frequent outcome of HR and were found in both "hot and cold" regions. The length of the conversion tracts was variable, ranging from 5 to 7505 bp. In addition, a typical feature of these tracks was that they often were interrupted. Our findings pave the way for the use of targeted gene-conversion for precise breeding.
Subject(s)
Arabidopsis/genetics , Euchromatin/genetics , Heterochromatin/genetics , Homologous Recombination/genetics , Arabidopsis/growth & development , CRISPR-Cas Systems/genetics , DNA Breaks, Double-Stranded , DNA End-Joining Repair/genetics , Genome, Plant/genetics , Recombinational DNA Repair/geneticsABSTRACT
The version of Supplementary Table 1 originally published online with this article contained incorrect localization annotations for one plate. This error has been corrected in the online Supplementary Information.
ABSTRACT
Yeast libraries revolutionized the systematic study of cell biology. To extensively increase the number of such libraries, we used our previously devised SWAp-Tag (SWAT) approach to construct a genome-wide library of ~5,500 strains carrying the SWAT NOP1promoter-GFP module at the N terminus of proteins. In addition, we created six diverse libraries that restored the native regulation, created an overexpression library with a Cherry tag, or enabled protein complementation assays from two fragments of an enzyme or fluorophore. We developed methods utilizing these SWAT collections to systematically characterize the yeast proteome for protein abundance, localization, topology, and interactions.
