The SWI/SNF ATP-Dependent Chromatin Remodeling Complex in Arabidopsis Responds to Environmental Changes in Temperature-Dependent Manner

Abstract

SWI/SNF ATP-dependent chromatin remodeling complexes (CRCs) play important roles in the regulation of transcription, cell cycle, DNA replication, repair, and hormone signaling in eukaryotes. The core of SWI/SNF CRCs composed of a SWI2/SNF2 type ATPase, a SNF5 and two of SWI3 subunits is sufficient for execution of nucleosome remodeling in vitro. The Arabidopsis genome encodes four SWI2/SNF2 ATPases, four SWI3, a single SNF5 and two SWP73 subunits. Genes of the core SWI/SNF components have critical but not fully overlapping roles during plant growth, embryogenesis, and sporophyte development. Here we show that the Arabidopsis swi3c mutant exhibits a phenotypic reversion when grown at lower temperature resulting in partial restoration of its embryo, root development and fertility defects. Our data indicates that the swi3c mutation alters the expression of several genes engaged in low temperature responses. The location of SWI3C-containing SWI/SNF CRCs on the ICE1, MYB15 and CBF1 target genes depends on the temperature conditions, and the swi3c mutation thus also influences the transcription of several cold-responsive (COR) genes. These findings, together with genetic analysis of swi3c/ice1 double mutant and enhanced freezing tolerance of swi3c plants illustrate that SWI/SNF CRCs contribute to fine-tuning of plant growth responses to different temperature regimes.

Chromatin, Epigenetics and Plant Physiology

“…Their observations support the idea of evolutionary conservation of SWI3 physiological functions in different plant species. Similarly, the involvement of the SWI subunits of the chromatin remodeling complex in temperature-dependent regulation of plant growth and developmental responses in Arabidopsis is reported by Gratkowska-Zmuda et al [6]. Altogether, these results demonstrate the importance of the proper chromatin remodeling in crucial cellular processes, including gene expression, cell cycle regulation, DNA replication and repair, and hormone signaling.…”

Pinus spp. Somatic Embryo Conversion under High Temperature: Effect on the Morphological and Physiological Characteristics of Plantlets

“…The pressures exerted by high temperatures and drought affect numerous defense mechanisms in plants [41], such as changes in photosynthetic machinery [42]. This can happen at an embryogenic level with the formation of an epigenetic memory [4] even at the plant level.…”

Chemical Inhibitors of a Selective SWI/SNF Function Synergize with ATR Inhibition in Cancer Cell Killing

“…The human genome encodes 29 ATPases related to the chromatin remodeling ATPase, SWI2/SNF2, which was first discovered in yeast. , These ATPases are largely nonredundant and often observed as multisubunit assemblies . Among this family of ATP-dependent chromatin regulators, mSWI/SNF or BAF (Brg Associated Factor) complexes are highly mutated in human cancer and appear to play dose-dependent roles in tumor suppression, neural development, oncogenesis, and maintaining HIV latency. − These complexes are combinatorially assembled from 16 subunits encoded by 31 genes (Figure A) giving them specific but distinct roles in many biologic processes. , Recently, BAF complexes have been found to take on noncanonical assemblies (ncBAF), − , which are essential in malignant rhabdoid tumors and synovial sarcoma (Figure A). Although many of the subunits are required for essential cellular mechanisms, , other subunits have highly selective functions. − For example, the nBAF complex, found only in neurons, is also combinatorially assembled and plays instructive roles in reprogramming fibroblasts to neurons .…”