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Research article - Peer-reviewed, 2018

The function of two type II metacaspases in woody tissues of Populus trees

Bollhoner, Benjamin; Jokipii-Lukkari, Soile; Bygdell, Joakim; Stael, Simon; Adriasola, Mathilda; Muniz, Luis; Van Breusegem, Frank; Ezcurra, Ines; Wingsle, Gunnar; Tuominen, Hannele


Metacaspases (MCs) are cysteine proteases that are implicated in programmed cell death of plants. AtMC9 (Arabidopsis thaliana Metacaspase9) is a member of the Arabidopsis MC family that controls the rapid autolysis of the xylem vessel elements, but its downstream targets in xylem remain uncharacterized.PttMC13 and PttMC14 were identified as AtMC9 homologs in hybrid aspen (Populustremulaxtremuloides). A proteomic analysis was conducted in xylem tissues of transgenic hybrid aspen trees which carried either an overexpression or an RNA interference construct for PttMC13 and PttMC14.The proteomic analysis revealed modulation of levels of both previously known targets of metacaspases, such as Tudor staphylococcal nuclease, heat shock proteins and 14-3-3 proteins, as well as novel proteins, such as homologs of the PUTATIVE ASPARTIC PROTEASE3 (PASPA3) and the cysteine protease RD21 by PttMC13 and PttMC14.We identified here the pathways and processes that are modulated by PttMC13 and PttMC14 in xylem tissues. In particular, the results indicate involvement of PttMC13 and/or PttMC14 in downstream proteolytic processes and cell death of xylem elements. This work provides a valuable reference dataset on xylem-specific metacaspase functions for future functional and biochemical analyses.


aspartic protease; cellular autolysis; cysteine protease; metacaspase; Populus; programmed cell death; wood formation; xylem differentiation

Published in

New Phytologist
2018, volume: 217, number: 4, pages: 1551-1565
Publisher: WILEY

Authors' information

Bollhöner, Benjamin
Umeå University
Jokipii-Lukkari, Soile
Umeå University
Bygdell, Joakim
Umeå University
Stael, Simon
Ghent University
Adriasola, Mathilda
Royal Institute of Technology (KTH)
Muñiz, Luis
Umeå University
Van Breusegem, Frank
Ghent University
Ezcurra, Ines
Royal Institute of Technology (KTH)
Swedish University of Agricultural Sciences, Department of Forest Genetics and Plant Physiology
Tuominen, Hannele
Umeå University

UKÄ Subject classification

Biochemistry and Molecular Biology

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