Rice (Oryza sativa) seedlings are sensitive to chilling. Hence, improvement
of chilling tolerance in rice could increase rice quality and production.
The team of Huang Xiao Zhen from Guizhou University in China isolated a
transcription factor, TIFY1b, which could be involved in rice cold
resistance. To explore the function of TIFY1b and its homologue, TIFY1a,
CRISPR-Cas9 was used to edit their genome.

The rice cultivar Nipponbare was transformed using the CRISPR-Cas9
technique. Analysis of the T0 transgenic lines showed mutagenesis frequency
ranging from 60% to 87.5%. These results suggest that CRISPR-Cas9 systems
can effectively induce site-specific mutations in rice. Protein analysis
showed that mutations caused function loss of TIFY1a or TIFY1b genes in T0
transgenic mutants. The mutations were also found to be inherited stably
into the next generation.

A series of tify1 mutant lines were successfully obtained which would be
used to investigate the role of TIFY1 genes in rice adaptation to chilling
temperature. These studies might reveal a pathway that controls cold
adaptation in rice and will help in the development of cold-tolerant rice
cultivars.

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