Plasticity of rosette size in response to nitrogen availability is
controlled by an RCC1-family protein
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, using
Arabidopsis 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 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.