Abstract
Nitrogen (N) is fundamental to plant growth, development, and yield.
Genes underlying N utilization and assimilation are well-characterized,
but mechanisms underpinning plasticity of different phenotypes to
varying amounts of N in the soil remain elusive. Here, usingArabidopsis thaliana accessions, we dissected the genetic
architecture of plasticity in early and late rosette diameter, flowering
time and yield in response to three levels of N in soil. Genome-wide
association analysis identified three significant associations for
phenotypic plasticity, one for early rosette diameter and two for
flowering time. We confirmed that the gene At1g19880 , hereafter
named as PLASTICITY OF ROSETTE TO NITROGEN 1(PROTON1 ), encoding for a regulator of chromatin
condensation 1 (RCC1) family protein, conferred the plasticity of
rosette diameter in response to changes in N availability. The altered
plasticities were a result of faster development under limiting N, and
correlated with the plasticity in the levels of primary metabolites. By
using different growth conditions for a subset of accessions, we showed
that plasticities of growth and flowering-related traits in response to
N availability differed between the environmental cues, indicating
decoupled genetic programs regulating these traits. Our findings provide
a prospective for identification of genes that stabilize performance
under fluctuating environments.