![](https://plantae.org/wp-content/uploads/2023/04/rajarshi-sigma.png)
SIGMA FACTOR5 protects freezing plants
Low temperatures quickly and reversibly inhibit photosynthesis, which is assumed to shield the photosynthetic system from a drop in metabolic activity brought about by cold. In a recent study, Cano-Ramirez et al. found that in Arabidopsis, a nuclear-encoded sigma factor (SIG5) controls chloroplast transcription…