Characterization of a plant lamin-like protein in Marchantia

The nuclear lamina (NL) is a complex network of nuclear lamins and lamin-associated nuclear membrane
proteins, which scaffold the nucleus to maintain structural integrity. In
animals, type V intermediate filaments are the main constituents of nuclear
lamina. Plant genomes do not encode any homologs of these intermediate
filaments, yet plant nuclei contain lamina-like structures. In Arabidopsis
thaliana, Nuclear Matrix Constituent proteins (NMCPs), which are required for maintaining
structural integrity of the nucleus and specific perinuclear chromatin
anchoring, function as nuclear lamins. Recent studies revealed additional roles
of Arabidopsis NMCPs in
modulating plants’ response to pathogen and abiotic stress. However, detailed
analyses of Arabidopsis NMCP activities are difficult due to the
presence of multiple homologs and their functional redundancy. In this study,
we investigated the sole NMCP gene in the liverwort Marchantia
polymorpha (MpNMCP). We found that MpNMCP proteins preferentially were
localized to the nuclear periphery. Using CRISPR-Cas9 techniques, we generated MpNMCP
loss-of-function mutant, which displayed reduced growth rate and
curly thallus lobe. Transcriptome analyses indicated that MpNMCP was
involved in regulating biotic and abiotic stress responses. Besides, a highly
repetitive genomic region on the male sex chromosome, which was preferentially
tethered at the nuclear periphery in wild-type thalli, decondensed and located
in the nuclear interior. This perinuclear chromatin anchoring, however, was not
directly controlled by MpNMCP. Altogether, our results unveiled that NMCP
in plants have conserved functions in modulating both perinuclear chromatin
localization and stress responses.

This repository contains normalized Hi-C data (10 kb bin for individual chromosomes, 50 kb bin for genome-wide) generated from Tak-1 and MpNMCP mutant thalli.