Arabidopsis thaliana Subclass I ACTIN DEPOLYMERIZING FACTORs Regulate Nuclear Organization and Gene Expression

Tomoko Matsumoto; Takumi Higaki; Hirotomo Takatsuka; Natsumaro Kutsuna; Yoshiyuki Ogata; Seiichiro Hasezawa; Masaaki Umeda; Noriko Inada

doi:10.1093/pcp/pcad092

Arabidopsis thaliana Subclass I ACTIN DEPOLYMERIZING FACTORs Regulate Nuclear Organization and Gene Expression

Plant Cell Physiol. 2023 Oct 16;64(10):1231-1242. doi: 10.1093/pcp/pcad092.

Authors

Tomoko Matsumoto¹, Takumi Higaki^{2

3}, Hirotomo Takatsuka, Natsumaro Kutsuna⁴, Yoshiyuki Ogata¹, Seiichiro Hasezawa⁵, Masaaki Umeda⁶, Noriko Inada^{1

6}

Affiliations

¹ Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531 Japan.
² Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuou-ku, Kumamoto, 860-8555 Japan.
³ International Research Organization for Advanced Science and Technology (IROAST), Kumamoto University, 2-39-1 Kurokami, Chuou-ku, Kumamoto, 860-8555 Japan.
⁴ LPIXEL, Inc., 1-6-1 Otemachi, Chiyoda-ku, Tokyo, 100-0004 Japan.
⁵ Graduate School of Science and Engineering, Hosei University, Kajino-cho 3-7-2 Koganei, Tokyo, 184-8584 Japan.
⁶ Graduate School of Science and Technology, Nara Institute of Science and Technology, Takayama-cho 8916-5 Ikoma, Nara, 630-0192 Japan.

PMID: 37647615
DOI: 10.1093/pcp/pcad092

Abstract

ACTIN DEPOLYMERIZING FACTOR (ADF) is a conserved protein that regulates the organization and dynamics of actin microfilaments. Eleven ADFs in the Arabidopsis thaliana genome are grouped into four subclasses, and subclass I ADFs, ADF1-4, are all expressed throughout the plant. Previously, we showed that subclass I ADFs function in the regulation of the response against powdery mildew fungus as well as in the regulation of cell size and endoreplication. Here, we report a new role of subclass I ADFs in the regulation of nuclear organization and gene expression. Through microscopic observation of epidermal cells in mature leaves, we found that the size of chromocenters in both adf4 and transgenic lines where expression of subclass I ADFs is downregulated (ADF1-4Ri) was reduced compared with that of wild-type Col-0. Arabidopsis thaliana possesses eight ACTIN (ACT) genes, among which ACT2, -7 and -8 are expressed in vegetative organs. The chromocenter size in act7, but not in the act2/8 double mutant, was enlarged compared with that in Col-0. Microarray analysis revealed that 1,818 genes were differentially expressed in adf4 and ADF1-4Ri. In particular, expression of 22 nucleotide-binding leucine-rich repeat genes, which are involved in effector-triggered plant immunity, was reduced in adf4 and ADF1-4Ri. qRT-PCR confirmed the altered expressions shown with microarray analysis. Overall, these results suggest that ADF regulates various aspects of plant physiology through its role in regulation of nuclear organization and gene expression. The mechanism how ADF and ACT regulate nuclear organization and gene expression is discussed.

Keywords: Arabidopsis thaliana; ACTIN DEPOLYMERIZING FACTOR; Actin; Heterochromatin; Nucleus; Regulation of gene expression.

Abstract

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