植物科学

CRISPR/Cas9 is an established and flexible tool for genome editing. However, most methods used to generate expression clones for the CRISPR/Cas9 are time-consuming. Hence, we have developed a one-step protocol to introduce sgRNA expression cassette(s) directly into binary vectors (Liu et al., 2020). In this approach, we have optimized the multiplex PCR to produce an overlapping PCR product in a single reaction to generate the sgRNA expression cassette. We also amplified two sgRNA expression cassettes through a single round of PCR. Then, the sgRNA expression cassette(s) is cloned into the binary vectors in a Gateway LR or Golden gate reaction. The system reported here provides a much more efficient and simpler procedure to construct expression clones for CRISPR/Cas9-mediated genome editing. In this protocol, we describe the detailed step-by-step instructions for using this system.

CRISPR/Cas9 system directed by a gene-specific single guide RNA (sgRNA) is an effective tool for genome editing such as deletions of few bases in coding genes. However, targeted deletion of larger regions generate loss-of-function alleles that offer a straightforward starting point for functional dissections of genomic loci. We present an easy-to-use strategy including a fast cloning dual-sgRNA vector linked to efficient isolation of heritable Cas9-free genomic deletions to rapidly and cost-effectively generate a targeted heritable genome deletion. This step-by-step protocol includes gRNA design, cloning strategy and mutation detection for Arabidopsis and may be adapted for other plant species.

Methylation-Sensitive Amplification Polymorphism (MSAP) is a versatile marker for analyzing DNA methylation patterns in non-model species. The implementation of this technique does not require a reference genome and makes it possible to determine the methylation status of hundreds of anonymous loci distributed throughout the genome. In addition, the inheritance of specific methylation patterns can be studied. Here, we present a protocol for analyzing DNA methylation patterns through MSAP markers in potato interspecific hybrids and their parental genotypes.

Homologous genes, including paralogs and orthologs, are genes that share sequence homologies within or between different species. Homologous genes originate from a common origin through speciation, genetic duplication or horizontal gene transfer. Estimation of the sequence divergence of homologous genes help us to understand divergence time, which makes it possible to understand the evolutionary patterns of speciation, gene duplication and gene transfer events. This protocol will provide a detailed bioinformatics pipeline on how to identify the homologous genes, compare their sequence divergence and phylogenetic relationships, focusing on homologous genes that show syntenic relationships using soybean (Glycine max) and common bean (Phaseolus vulgaris) as example species.