Ecologists have put forward the root economics spectrum hypothesis by analyzing the acquisition-conservation trade off in root systems among different plants. Finer and cost-effective absorptive roots are seen in some plant species. These contribute to rapid nutrient uptake but have shorter lifespans. Other roots are thicker and less cost-effective absorptive. These roots have slower nutrient acquisition but longer lifespans. The RES hypothesis shows the correlations among different root traits. This can facilitate the adaptation of plants to the local environment. The RES is one of the main issues in root ecology. Though its adaptive role and genetic basis remains largely elusive.
Zhejiang University College of Life Sciences Prof. Weile Chen and University of Texas at Austin Prof. Thomas Juenger together have explored the molecular basis of the RES from the perspective of functional genetics. The findings of the research have been published in a research article named “The genetic basis of the root economics spectrum in a perennial grass” in the journal PNAS.
They have used a genetic mapping population of the native perennial switchgrass. The study confirmed that the multiple genetic linkages among root morphology, growth, and turnover. Switching alleles from lowland ecotypes to those from upland ecotypes reduces the cost of root construction. But at the same time, it increases the turnover of absorptive roots. The genetic trade-off between construction cost and turnover will facilitate the local adaptation of root strategy along the warm to cold climatic gradients of the species range.
The aboveground biomass of switchgrass is perceived as an alternative to fossil fuel. Also, its belowground root system helps store carbon captured by leaf photosynthesis in the soil.