Transcriptomics to unravel regulation of nutrient uptake rates upon
synthetic CEP1 peptide application in plant roots
Abstract
Plant roots are responsible for essential functions like nutrient
uptake, anchorage, and storage. Study of root uptake mechanisms for
macro nutrients like nitrogen, phosphorus, potassium, and sulphur is
vital to our understanding of their role in plant growth and
development. Small signaling peptides (SSPs), are hormones which
regulate diverse plant developmental processes including root growth.
However, their involvement in regulation of nutrient uptake by roots is
poorly understood. We recently developed a hydroponics- based plant
growth system which combines ion chromatography with synthetic peptide
application, to analyze the depletion rates of nutrients by Medicago
truncatula roots. Application of the synthetic SSP MtCEP1 and AtCEP1 led
to enhanced uptake of nitrates, sulphates, and phosphates. To further
elucidate the molecular mechanism of nutrient uptake mediated by these
peptides, we conducted an RNAseq of M. truncatula roots treated with the
peptides. A differential gene expression analysis revealed thousands of
peptide responsive genes. Several known nitrate transporters and a
sulphate transporter AtSULTR3:5-like gene showed enhanced expression
under both, MtCEP1 and AtCEP1 peptide application. Multiple, as of yet
uncharacterized, CEP peptide responsive pathway regulatory genes such as
kinases and transcription factors were also identified through this
transcriptomic analysis. This study highlights the potential of
phenomics enabled biology to uncover target genes for improving
agriculturally important traits such as nutrient uptake.