Crop Biotech Update

CRISPR-Cas9 Helps Explain Maize Adaptation to Higher Latitudes

March 7, 2018

Flowering time is a critical determinant of crop adaptation to local environments. Maize has spread over a wide latitudinal cline in the Americas due to its reduced photoperiod sensitivity to adapt to regions over 90° of latitude.

The team of Cheng Huang from China Agricultural University aimed to explain how maize adapts to environments above 90° of latitude. The team found that ZmCCT9 regulates flowering under the long days, allowing maize to adapt to higher latitudes. Using CRISPR-Cas9, the team knocked-out ZmCCT9 in maize to further analyze its role.

Analysis of the generated mutants revealed that the gene knockout caused early flowering under long days. Further analysis also found that ZmCCT9 negatively regulates the expression of the florigen ZCN8, resulting in late flowering under long days.

These findings help explain how the maize genome with enable maize to adapt over 90° of latitude.

For more information, read the article in Proceedings of the National Academy of Sciences.