Scientists from Chinese Academy of Agricultural Sciences and partners used CRISPR-Cas9 to find out about the responsive regulation of inorganic pyrophosphatase in rice under alkaline stress. The results are published in Frontiers in Plant Science. 

Alkaline stress is one of the abiotic factors that affect plant growth and development. Inorganic pyrophosphatase is an enzyme used in various biological processes linked to abiotic stress response. Thus, researchers used the CRISPR-Cas9 system for the mutagenesis of the OsPPa6 gene, which codes for an inorganic pyrophosphatase in rice. Two similar Cas9-free mutants were obtained which exhibited delayed growth and development, particularly under alkaline stress. Tests also showed that mutagenesis of OSPPa6 was significantly induced by alkaline stress. Furthermore, results indicated that pyphosphate contents in the mutants were higher than those in the wild type when under alkaline stress,but the buildup of inorganic phosphate, ATP, chlorophyll, sucrose, and starch in the mutants were significantly reduced. Mutagenesis of OsPPa6 lowered the rate of photosynthesis in rice mutants. 

Based on the findings, it was concluded that OSPPa6 gene is a vital osmotic regulatory factor in rice and CRISPR-Cas9 is an effective tool in assessing the responsive regulation of stress-induced gene. 

Read the abstract in Frontiers in Plant Science.