Cell cycle follows ‘pause and play’ mechanism in salt and cold stress recovery in diverse plant species

Changes to organismal growth induced by environmental stress are orchestrated at the cellular level. These periods of stress may be followed by recovery periods, when plants have the opportunity to return to normal growth conditions. However, the cell cycle mechanisms underlying recovery are poorly understood. We tested the cell cycle regulation in roots during control, stress, and recovery period for salt, osmotic, cold, and heat stresses using Arabidopsis thaliana, Brachypodium distachyon, and Lolium multiflorum. During the salt and cold stress conditions, the cell cycle pauses at gap phase and is released from gap phase during stress recovery, which depends on cell cycle regulators CDKA;1 and ICK1. Cold stress and recovery, which affect cell division only, follow a conserved 'pause and play' mechanism of the cell cycle.