Nuclear calcium signatures are associated with root development

Nuno Leitão,Ross Carter,Pierre Dangeville,Myriam Charpentier

doi:10.1038/s41467-019-12845-8

Nuno Leitão, Ross Carter + Show 2 more

Open Access

https://doi.org/10.1038/s41467-019-12845-8

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Abstract

In plants, nuclear Ca2+ releases are essential to the establishment of nitrogen-fixing and phosphate-delivering arbuscular mycorrhizal endosymbioses. In the legume Medicago truncatula, these nuclear Ca2+ signals are generated by a complex of nuclear membrane-localised ion channels including the DOES NOT MAKE INFECTIONS 1 (DMI1) and the cyclic nucleotide-gated channels (CNGC) 15s. DMI1 and CNCG15s are conserved among land plants, suggesting roles for nuclear Ca2+ signalling that extend beyond symbioses. Here we show that nuclear Ca2+ signalling initiates in the nucleus of Arabidopsis root cells and that these signals are correlated with primary root development, including meristem development and auxin homeostasis. In addition, we demonstrate that altering genetically AtDMI1 is sufficient to modulate the nuclear Ca2+ signatures, and primary root development. This finding supports the postulate that stimulus-specific information can be encoded in the frequency and duration of a Ca2+ signal and thereby regulate cellular function.

Highlights

In plants, nuclear Ca2+ releases are essential to the establishment of nitrogen-fixing and phosphate-delivering arbuscular mycorrhizal endosymbioses
Transcriptomic data suggest that AtDMI1 and AtCNGC15 are expressed in diverse Arabidopsis tissues
We purified mRNA from roots, leaves, stems, and siliques of Arabidopsis and confirmed by reverse transcription quantitative polymerase chain reaction (RT-qPCR) that both AtDMI1 and AtCNGC15 are expressed in all tissues analysed including roots (Supplementary Fig. 2)

Summary

Introduction

Nuclear Ca2+ releases are essential to the establishment of nitrogen-fixing and phosphate-delivering arbuscular mycorrhizal endosymbioses. We demonstrate that altering genetically AtDMI1 is sufficient to modulate the nuclear Ca2+ signatures, and primary root development This finding supports the postulate that stimulus-specific information can be encoded in the frequency and duration of a Ca2+ signal and thereby regulate cellular function. Within the same cellular compartment, it is postulated that the Ca2+ signature, defined by its amplitude, frequency, and duration, specifies the activation of downstream components[2] This postulate is well accepted, the genetic demonstration that modulating a Ca2+ signature can change a specific developmental or physiological process is still missing. The findings in this study reveal that genetically modulating the activity of ion channels to produce diverse Ca2+ signatures is sufficient to control developmental processes and further highlight the novel function of DMI1 in modulating nuclear Ca2+ signals required for primary root growth

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