Divide et impera: boundaries shape the plant body and initiate new meristems

• Published in: The New phytologist Vol. 209; no. 2; pp. 485 - 498
• Main Authors: Wang, Quan, Hasson, Alice, Rossmann, Susanne, Theres, Klaus
• Format: Journal Article
• Language: English
• Published: England Academic Press 01.01.2016; New Phytologist Trust; Wiley Subscription Services, Inc
• Subjects: apical meristems; Arabidopsis; Auxins; axillary meristem; Boundaries; boundary zone; Brassinosteroids; Brassinosteroids - metabolism; Cell differentiation; Cell Division; Cells; compound leaf; ectopic meristem; Gene expression; gene expression regulation; Gene Expression Regulation, Developmental; Hormones; Indoleacetic Acids - metabolism; leaf development; Leaves; Meristem - cytology; Meristem - genetics; Meristem - growth & development; Meristems; Plant growth substances; plant hormones; Plant Leaves - cytology; Plant Leaves - growth & development; Plant Leaves - metabolism; Plant Shoots - growth & development; Pluripotency; shoot meristems; Tansley reviews; tomato (Solanum lycopersicum); tomato (Solanum lycopersicum); axillary meristem; compound leaf; ectopic meristem; Arabidopsis; boundary zone
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.13641

485 I. 485 II. 486 III. 491 IV. 491 V. 495 495 References 495 SUMMARY: Boundaries, established and maintained in different regions of the plant body, have diverse functions in development. One role is to separate different cell groups, for example the differentiating cells of a leaf primordium from the pluripotent cells of the apical meristem. Boundary zones are also established during compound leaf development, to separate young leaflets from each other, and in many other positions of the plant body. Recent studies have demonstrated that different boundary zones share similar properties. They are characterized by a low rate of cell divisions and specific patterns of gene expression. In addition, the levels of the plant hormones auxin and brassinosteroids are down‐regulated in boundary zones, resulting in a low differentiation level of boundary cells. This feature seems to be crucial for a second important role of boundary zones, the formation of new meristems. The primary shoot meristem, as well as secondary and ectopic shoot meristems, initiate from boundary cells that exhibit competence for meristem formation.