Review: Thriving under stress: How plants balance growth and stress response (Devel. Cell)
What exactly is the growth/defense tradeoff? This review is an excellent place to ask. Zhang et al. review evidence that shows that it is much more than a competition for limiting resources – the plant actively responds to stress in ways that may slow growth but ultimately promote survival. The authors thoroughly summarize key stress signaling molecules such as ROS, and regulatory proteins including the very important SNF1-related protein kinases (SnRKs). They also describe the crucial role of the ABA pathway in stress signaling and response. They then discuss the mechanisms by which stress affects growth, in terms of cell cycle control and cell expansion, energy balance, and the TOR growth-promoting complexes. A key conclusion is that there is not one “see-saw”-like control point, but rather many signals that are integrated into these reciprocal outcomes. The authors note that efforts to breed stress-resistant crops have been largely unsuccessful due to the unintended negative impacts on growth. However, they stress that new insights are likely to break the growth-defense tradeoff, for example by lowering the plants sensitivity to stress signaling or using more finely tuned or tissue-specific interventions. (Summary by Mary Williams @PlantTeaching) Devel. Cell 10.1016/j.devcel.2020.10.012