PlaCCI (Plant cell cycle indicator); fluorescent sensor for spatiotemporal cell cycle analysis (Nature Plants)

The cell cycle requires a series of transitions from G1 to S, S to G2, G2 to M and M to G1 phases. Determining the cell cycle phase is critical for understanding the molecular events specific to a given stage of cell cycle. However, markers for identifying these cell cycle transitions in plants are not well established. Here, Desvoyes et al. designed and evaluated cell-cycle specific markers  in Arabidopsis. The authors used CDT1a (replication initiator protein)-CFP, H3.1 (Histone protein)-mRFP, and CYCB1;1-GFP as markers for G1, S + early G2, and late G2 + M phase respectively. The markers were individually evaluated in independent transgenic lines; however, these individual reporters are not amenable for analyzing all phases of cell cycle as one has to combine these lines genetically. To make it handier, the authors designed all three reporters in the same construct and named it plant cell cycle indicator (PlaCCI). PlaCCI allows live imaging of cell cycle markers in various organs like roots, leaf, petiole, meristem and trichomes. The authors observed that PlaCCI doesn’t affect the cellular growth, meristem size, or enoreduplication status and can be used with various drug treatments and mutant background. (Summary by Vijaya Batthula @Vijaya_Batthula) Nature Plants 10.1038/ s41477-020-00770-4