Biomass Allocation in Response to Nitrogen and Phosphorus Availability: Insight From Experimental Manipulations of Arabidopsis thaliana

Abstract

Allocation of biomass to different organs is a fundamental aspect of plant responses and adaptations to changing environmental conditions, but how it responds to nitrogen (N) and phosphorus (P) availability remains poorly addressed. Here we conducted greenhouse fertilization experiments using Arabidopsis thaliana , with five levels of N and P additions and eight repeat experiments, to ascertain the effects of N and P availability on biomass allocation patterns. N addition increased leaf and stem allocation, but decreased root and fruit allocation. P addition increased stem and fruit allocation, but decreased root and leaf allocation. Pooled data of the five levels of N addition relative to P addition resulted in lower scaling exponents of stem mass against leaf mass (0.983 vs. 1.226; p = 0.000), fruit mass against vegetative mass (0.875 vs. 1.028; p = 0.000), and shoot mass against root mass (1.069 vs. 1.324; p = 0.001). This suggested that N addition relative to P addition induced slower increase in stem mass with increasing leaf mass, slower increase in reproductive mass with increasing vegetative mass, and slower increase in shoot mass with increasing root mass. Further, the levels of N or P addition did not significantly affect the allometric relationships of stem mass vs. leaf mass, and fruit mass vs. vegetative mass. In contrast, increasing levels of N addition increased the scaling exponent of shoot to root mass, whereas increasing levels of P addition exerted the opposite influence on the scaling exponent. This result suggests that increasing levels of N addition promote allocation to shoot mass, whereas the increasing levels of P addition promote allocation to root mass. Our findings highlight that biomass allocation of A. thaliana exhibits a contrasting response to N and P availability, which has profound implications for forecasting the biomass allocation strategies in plants to human-induced nutrient enrichment.

Sugar Beet Shoot and Root Phenotypic Plasticity to Nitrogen, Phosphorus, Potassium and Lime Omission

“…Plants respond to nutrient limitations by changing their root shoot ratio. In low nutrient conditions, the allocation of biomass to the roots is often favored [41,42]. Our results in the late growth stage (July and September) confirmed that in low nutrient conditions, the root shoot ratio-but not the absolute tuber yield of sugar beet-was enhanced in the N omission treatment.…”

Potentially peat‐forming biomass of fen sedges increases with increasing nutrient levels

“…during the vegetation period range from under 0.05 to over 5.5 (Aerts et al, 1992;Bernard et al, 1988;Konings et al, 1992;Kotowski et al, 2006;Sjörs, 1991). An increase in biomass allocation to shoots under elevated nutrient levels, as observed in our study, seems to be a common response in different plant species and plant communities, including Carex species (Aerts et al, 1992;Müller et al, 2000;Peng & Yang, 2016;Poorter et al, 2012;Yan et al, 2019). Possibly, under lower nutrient supply relatively more biomass is allocated below-ground to increase nutrient uptake, whereas under higher nutrient supply, relatively more biomass is allocated above-ground to maximize photosynthetic yield (Aerts et al, 1992) and to compete for light (Kotowski et al, 2006).…”

Oilseed Rape Cultivars Show Diversity of Root Morphologies with the Potential for Better Capture of Nitrogen

“…In the model species, a dual effect of nitrate on lateral root development is described: (i) a systemic inhibition of uniformly elevated nitrate concentrations occurs on lateral root elongation at the post-emergence developmental stage and (ii) a localized stimulation of nitrate-rich patches triggers lateral root growth in a low N environment, known as the foraging capacity [24][25][26][27]. The exploitation of Arabidopsis has unveiled some molecular networks shaping root morphology in response to nutritional factors [28][29][30][31][32].…”