Genome-wide association mapping identifies an SNF4 ortholog that impacts biomass and sugar yield in sorghum and sugarcane.

Sorghum is a feed/industrial crop in developed countries and a staple food elsewhere in the world. This study evaluated the sorghum mini core collection for days to 50% flowering (DF), biomass, plant height (PH), soluble solid content (SSC), and juice weight (JW), and the sorghum reference set for DF and PH, in 7-12 testing environments. We also performed genome-wide association mapping with 6 094 317 and 265 500 single nucleotide polymorphism markers in the mini core collection and the reference set, respectively. In the mini core panel we identified three quantitative trait loci for DF, two for JW, one for PH, and one for biomass. In the reference set panel we identified another quantitative trait locus for PH on chromosome 6 that was also associated with biomass, DF, JW, and SSC in the mini core panel. Transgenic studies of three genes selected from the locus revealed that Sobic.006G061100 (SbSNF4-2) increased biomass, SSC, JW, and PH when overexpressed in both sorghum and sugarcane, and delayed flowering in transgenic sorghum. SbSNF4-2 encodes a γ subunit of the evolutionarily conserved AMPK/SNF1/SnRK1 heterotrimeric complexes. SbSNF4-2 and its orthologs will be valuable in genetic enhancement of biomass and sugar yield in plants.

Generating Mutant for a Stress-Responsive Gene in Rice Using CRISPR-Cas9 System.

CRISPR/Cas9 system is one of the most often utilized engineering tools for genome editing in many organisms including crop plants and presents great value in both basic and applied research. This is a preferred method because of its relative simplicity, cost-effectiveness, and reliability. The Cas9 nuclease guided by a short single guide RNA (gRNA) can generate double-strand DNA breaks (DSB) at the specific sites in chromosomal DNA. The DSB site is repaired by error-prone repair methods. During repair, some nucleotides are deleted or added at the target site. Here, we present a simplified protocol for generating mutants in gene of interest in rice using CRISPR/Cas9.