During the past century, agriculture moved beyond the knowledge of local farmers to become a global endeavor. Investments in fundamental plant biology and agriculture revolutionized food production, but larger problems loom ahead. To meet the challenges of this century, plant biologists are working on many fronts, some highlighted here, to make sustainability a reality. In this next green movement, new technologies and multidisciplinary approaches are enabling the translation of fundamental plant biology knowledge toward the reduction of inputs and ecological footprints.
Aside from technical hurdles, agro-economics, the evolutionary constraints of plants, and the public perception of plant biotechnology remain issues. Basic science opens many routes toward a sustainable future; however, crops are commodities with a narrow profit margin, which can temper the implementation of new varieties and practices. Breakthroughs must be useful, make economic sense, and be adaptable to multiple regions and agro-ecosystems worldwide. More frequently, the combination of classic breeding and genetic engineering supported by new technologies provides greater options. Natural variation remains essential for plant improvement, but biotechnology can target complicated traits not amenable to traditional breeding. This is especially noticeable as efforts shift away from a one-gene-one-trait model toward broader systems-level targets, in which key control points that regulate downstream steps are exploited or combined to regulate multiple pathways. This also highlights the potential limits of plant genetics. Modern crops evolved under "normal" conditions, and the diversity needed for breeding new traits to meet changing climate is not always available. Moreover, efforts to improve particular traits often ignore combinations of stresses, diseases, and altered inputs. Additional work needs to consider multiple simultaneous challenges to plant growth and can be aided by the integration of large data sets and modeling studies. There is also substantial progress toward a mechanistic understanding of the plant microbiome and how bacteria and fungi work with plants for nutrient mobilization. In particular, recent discoveries on the relationships between plants and fungi in nitrogen and phosphorus may lead to enhancing plant-microbe interactions to minimize inputs and environmental impacts. Last, the public perception of plant biotechnology necessitates the continued education of people about the potential, and the limitations, of both breeding and genetic engineering.
The coming decades will be an exciting time for plant biologists with an eye for how to use plants for environmental and sustainability applications. A single look at teosinte and maize and one sees how adaptable plants can be for meeting our needs. What remains to be seen is whether we can harness our understanding of plants to innovate fast enough to meet the challenges poised by 9 billion people in 2050.