TY - JOUR

T1 - 3D analysis of mitosis distribution highlights the longitudinal zonation and diarch symmetry in proliferation activity of the Arabidopsis thaliana root meristem

AU - Lavrekha, Viktoriya V.

AU - Pasternak, Taras

AU - Ivanov, Victor B.

AU - Palme, Klaus

AU - Mironova, Victoria V.

N1 - © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

PY - 2017/12/1

Y1 - 2017/12/1

N2 - To date CYCB1;1 marker and cortex cell lengths have been conventionally used to determine the proliferation activity of the Arabidopsis root meristem. By creating a 3D map of mitosis distribution we showed that these markers overlooked that stele and endodermis save their potency to divide longer than the cortex and epidermis. Cessation of cell divisions is not a random process, so that mitotic activity within the endodermis and stele shows a diarch pattern. Mitotic activity of all root tissues peaked at the same distance from the quiescent center (QC); however, different tissues stopped dividing at different distances, with cells of the protophloem exiting the cell cycle first and the procambial cells being the last. The robust profile of mitotic activity in the root tip defines the longitudinal zonation in the meristem with the proliferation domain, where all cells are able to divide; and the transition domain, where the cell files cease to divide. 3D analysis of cytokinin deficient and cytokinin signaling mutants showed that their proliferation domain is similar to that of the wild type, but the transition domain is much longer. Our data suggest a strong inhibitory effect of cytokinin on anticlinal cell divisions in the stele.Significance Statement 3D analysis of mitosis distribution in the Arabidopsis root meristem showed that there are two domains: in the proliferation domain all cells are able to divide; in the transition domain progressive cessation of cell divisions occurs within different cell files according to a diarch pattern. Protophloem ceases to divide the first, procambium the last, and the cortex cell starts to elongate in the middle.

AB - To date CYCB1;1 marker and cortex cell lengths have been conventionally used to determine the proliferation activity of the Arabidopsis root meristem. By creating a 3D map of mitosis distribution we showed that these markers overlooked that stele and endodermis save their potency to divide longer than the cortex and epidermis. Cessation of cell divisions is not a random process, so that mitotic activity within the endodermis and stele shows a diarch pattern. Mitotic activity of all root tissues peaked at the same distance from the quiescent center (QC); however, different tissues stopped dividing at different distances, with cells of the protophloem exiting the cell cycle first and the procambial cells being the last. The robust profile of mitotic activity in the root tip defines the longitudinal zonation in the meristem with the proliferation domain, where all cells are able to divide; and the transition domain, where the cell files cease to divide. 3D analysis of cytokinin deficient and cytokinin signaling mutants showed that their proliferation domain is similar to that of the wild type, but the transition domain is much longer. Our data suggest a strong inhibitory effect of cytokinin on anticlinal cell divisions in the stele.Significance Statement 3D analysis of mitosis distribution in the Arabidopsis root meristem showed that there are two domains: in the proliferation domain all cells are able to divide; in the transition domain progressive cessation of cell divisions occurs within different cell files according to a diarch pattern. Protophloem ceases to divide the first, procambium the last, and the cortex cell starts to elongate in the middle.

KW - Arabidopsis thaliana

KW - image processing

KW - iRoCS Toolbox

KW - mitosis

KW - patterning

KW - stem cell niche

KW - stem cells

KW - WHEAT ROOT

KW - PROTEIN

KW - PERICYCLE

KW - SIZE

KW - APICAL MERISTEM

KW - CELL-DIVISION

KW - SEQUENCE

KW - GROWTH

KW - DIFFERENTIATION

KW - MITOTIC-ACTIVITY

KW - Cell Proliferation

KW - Arabidopsis/growth & development

KW - Mitosis

KW - Plant Roots/growth & development

KW - Meristem/growth & development

KW - Imaging, Three-Dimensional

UR - http://www.scopus.com/inward/record.url?scp=85031711213&partnerID=8YFLogxK

U2 - 10.1111/tpj.13720

DO - 10.1111/tpj.13720

M3 - Article

C2 - 28921702

AN - SCOPUS:85031711213

VL - 92

SP - 834

EP - 845

JO - Plant Journal

JF - Plant Journal

SN - 0960-7412

IS - 5

ER -