Agriculture Reference
In-Depth Information
Figure 3.
Abiotic Stress affects root mitotic cycle. A) Lateral root formation responds to sucrose availability in medium
through an unknown link that enhances CycD4;1 expression in pericycle cells, allowing them to proliferate; it also re‐
sponds to low P availability through the activation of the auxin pathway. Auxin controls lateral root initiation through
the E2F mechanism, promoting the degradation of IAA14 and thus activating ARF7/18 transcription factors, subse‐
quently activating LBD18/33 factors which in turn bind and activate the promoter of the cell cycle-enabling E2F tran‐
scription factor. B) Meristematic maintenance also responds to diverse environmental changes. Through the
gibberellin pathway, DELLA proteins inhibit cell cycle progression by enhancing the accumulation of CDK inhibitors.
DELLAs are influenced by various environmental factors including light and temperature. These factors, as well as met‐
als and nutrient deficiency as in low P, promote the accumulation of ROS, known for inhibiting cell cycle in tobacco
cells. Interestingly, DELLAs promote survival by lowering the levels of ROS, indicating a novel pathway to maintain cell
cycle in the meristems. Salinity affects it by activating RSS1, required to maintain the mitotic cycle in the meristem. The
putative mechanism comprises RSS1 interacting with a type 1 protein phosphatase (PP1), regulating its activity at the
G1/S transition.
control pathway and ROS pathway in the developmental adaptation to the RS to low P
availability It requires further study to precise the way these signals crosstalk and determine
the developmental adaptation of the RS to low P availability by means of cell cycle progression
control, as well as additional efforts to reveal the manners by which other regulatory pathways
responding to abiotic stress interact with and influence the cell cycle control mechanisms.
5. Conclusion
Sensing and responding to environmental cues by roots enable plants to overcome the
challenges posed by their sessile lifestyle [10]. As we mentioned above, RS is important to
Search WWH ::
Custom Search