Researchers identify a key player in chromatin regulation in Arabidopsis thaliana

Chromatin is a unique DNA and protein complex that makes up chromosomes. Specific proteins (histones) wrap DNA so that long DNA can be packaged into small cable drums. A cable drum with coiled DNA (containing four pairs of histones) is called a nucleosome and is the smallest unit of chromatin.

Known as the supporting scaffold for chromatin, the nuclear matrix has fascinated scientists since its discovery in the 1970s. While its existence Mammalian cells was recognized, its importance in plant nuclei has ceased to exist. An international research team has now unraveled this mystery, shedding light on the structure of the nuclear matrix and how the nuclear matrix affects chromatin status and plant growth.

The study identified many nuclear matrix-associated proteins in Arabidopsis thaliana. Among them are known nuclear matrix proteins, including AtSUN1, AtSUN2, and AHL22, as well as FRS7 and FRS12. “This discovery expands our understanding of the molecular composition of the nuclear matrix,” says Prof. Dr. Hua Jiang, head of IPK’s independent research group “Applied Chromosome Biology”.

Research goes beyond just identifying ingredients; It is interested in understanding the functions of the nuclear matrix and associated proteins in chromatin regulation. Using genome-wide sequencing, researchers identified for the first time the genome-wide distribution of nuclear matrix-associated regions in plants.

“The results show a preference for the heads and tails of gene coding regions, which are mainly associated with active epigenetic marks and highly expressed genes, with some less expressed,” says Linhao Su, first author of the study. Genes also bind to the nuclear matrix,” says Linhao Xu, first author of the study. These findings suggest complex functions of the nuclear matrix in chromatin and transcriptional regulation.

Furthermore, the study unveils AHL22, cooperating with FRS7 and FRS12, as a central regulator in hypocotyl elongation, the upward growth of the embryonic axis in plant seedlings, which is shortened and root emergent. is between This process is essential for plant growth and survival. By regulating the expression of genes essential for the auxin signaling pathway, AHL22 acts as a conductor for chromatin and epigenetic regulators.

“The AHL22 complex orchestrates the association of genes with the nuclear matrix, recruiting the histone deacetylase HDA15 for modification. Histone acetylationsays Shiui Zheng, who is also the first author of the study. “This places the AHL22 complex as a central hub for chromatin regions and epigenetic regulators, revealing a previously unknown aspect of nuclear matrix function.”

Given that the nuclear matrix acts as a key regulator of chromatin and Chromatin In situ response to environmental changes, it becomes particularly interesting to explore the function of the nuclear matrix in response to conditioned stress.

Here are the results. published In the journal Nature Communications.