Plant-microbe mutualism, a special form of cooperation, has been crucial throughout the evolutionary history of life and terrestrial ecosystems. With human activities changing the condition of Earth’s surface at an unprecedented rate and scale, we expect this ancient bond between plants and microbes to continue to play a key role. Yet, despite its importance, there has been a historical bias towards cooperation/mutualism in biology, and a general underrepresentation in mathematical biology/theoretical ecology. Moreover, even though theoretical representation of mutualism has come a long way, there exists multiple disparate perspectives with diverse associated scientific communities, among which interaction has been limited. This review focuses on two seemingly opposite schools of perspectives: microbiologists’ perspective that zooms in for the microscale mechanisms vs. ecosystem ecologists’ perspective that zooms out for the macroscale consequences. Macroscale models often start with a simple set of naive assumptions. But over time microscale mechanisms (once understood well) will eventually be incorporated into newer-generation process-based large models, greatly enhancing our ability to quantitatively predict our future. I hope this review can facilitate this process, a process that will only become more important against the backdrop of rapid global change. Lastly, but perhaps more broadly, I hope this review will attract more attention to the important role of cooperation/mutualism, a concept that we can maybe leverage to solve a range of other broader problems in ecology and our society.