Authors

Schafer, Ernst, Markus R. Owen, Leah R. Band, Etienne Farcot, Malcolm J. Bennett, Jonathan P. Lynch

Source

Plant Physiology in press July 26 2022

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Plant Physiology

Abstract

Despite the widespread prevalence of root loss in plants, its effects on crop productivity are not fully understood. While root loss reduces the capacity of plants to take up water and nutrients from the soil, it may provide benefits by decreasing the resources required to maintain the root system. Using and extending the open-source, functional-structural root system simulation model OpenSimRoot, a range of root phenotypes were simulated in different soils and root loss scenarios for barley, common bean and maize. The model enabled us to quantify the impact of root loss on shoot dry weight in these scenarios and identify in which scenarios root loss is beneficial, detrimental or has no effect. The simulations showed that root loss is detrimental for phosphorus uptake in all tested scenarios whereas nitrogen uptake was relatively insensitive to root loss unless main root axes were lost. Loss of axial roots reduced shoot dry weight for all phenotypes in all species and soils, whereas lateral root loss had a smaller impact. In barley and maize plants with high lateral branching density that were not phosphorus-stressed, loss of lateral roots increased shoot dry weight. The fact that shoot dry weight increased due to root loss in these scenarios indicates that plants overproduce roots for some environments, such as those found in high-input agriculture. We conclude that a better understanding of the effects of root loss on plant development is an essential part of optimizing root system phenotypes for maximizing yield.