| Summary: The aim of this study is to analyze cell dynamics along the growth zone (meristem, elongation zone, mature zone) of maize leaves grown at low temperature. To this end, a kinematic analysis of leaf growth was performed. The results indicated that the reduction in leaf growth at low temperature was explained by a decrease in meristem cell production and division rate whereas cell expansion in the elongation zone was only marginally affected. Consequently, we analyzed the trancription of core cell cycle genes under the same environmental conditions. Low temperature resulted in changes in gene trancription level consistent with slower cell cycle progression: the level of several CDKs were downregulated and transcripts of some proteins inhibiting the cell cycle (KRPs, DELs) were upregulated. These results show that cell cycle in mature leaves is affected by low temperature and that understanding these effects at the molecular level may offer new strategies to improve growth and performance of crops under sub-optimum growth temperature.
Keywords: Zea mays cv. B73, Cell Cycle, Cell Growth, Leaf Development, CDK, KRP, DEL, E2F/DP, Kinematic Analyis, Flow Cytometry, Q-RT-PCR |
