Elucidating the mechanism of cell division during plant self-healing

Tsukuba, Japan—When the stem of a plant is injured, the surrounding cells proliferate to repair and fuse the damaged tissue, eventually restoring function. This self-healing property is utilized in grafting techniques to propagate fruit and vegetable plants. Prior research on this process has mainly concentrated on the initiation of cell proliferation. However, few studies have explored the inhibitory mechanisms that act as a brake on proliferation. In this new study, researchers studying Arabidopsis demonstrated that At2-MMP, a proteolytic enzyme, is vital to inhibit cell proliferation to repair severed flowering stems. By comparing tissue repair in Arabidopsis mutants lacking the At2-MMP gene (mutant at2-mmp) with wild-type plants, researchers found that the mutants exhibited abnormal cell proliferation at the injury site.

In severed wild-type Arabidopsis flowering stems, cell proliferation begins in pith cells (the center of the root and stem) approximately 3 days after cutting. At2-MMP transcripts gradually increase from day 0 to day 5 and decrease by day 7 to complete tissue repair. However, image analysis revealed abnormal cell division in at2-mmp mutants. Conversely, when At2-MMP was overexpressed, normal wound healing similar to that in wild-type plants was observed.

Overall, these findings indicate that At2-MMP contributes to tissue repair by suppressing cell division at the cleavage site and preventing abnormal cell proliferation. This process may reflect a survival strategy developed by immobile plants to enhance their self-healing ability.

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This work was funded by the Japan Society for the Promotion of Science KAKENHI (Grant Nos. 18075004, 24114006 and 17K08191 to H.I.), the 31st and 32nd Botanical Research Grant of ICHIMURA Foundation for New Technology (to H.I.), JST SPRING (Grant No. JPMJSP2124 to A.M.), Promotion and Mutual Aid Corporation for Private School of Japan (to M.A.), and ACRO Research Grant of Teikyo University (TeTe20-01 to M.A.).

_{Original Paper}

Title of original paper:
At2-MMP is required for attenuation of cell proliferation during wound healing in incised Arabidopsis inflorescence stems

Journal:
Plant and Cell Physiology

DOI:
10.1093/pcp/pcae103

_{Correspondence}

Associate Professor IWAI, Hiroaki
Institute of Life and Environmental Sciences, University of Tsukuba

Professor ASAHINA, Masashi
Department of Biosciences, Teikyo University

_{Related Link}

Institute of Life and Environmental Sciences