Walls around tumours — why plants do not develop cancer


In plants, as in animals, most cells that constitute the organism limit their reproductive potential in order to provide collective support for the immortal germ line. And, as in animals, the mechanisms that restrict the proliferation of somatic cells in plants can fail, leading to tumours. There are intriguing similarities in tumorigenesis between plants and animals, including the involvement of the retinoblastoma pathway as well as overlap with mechanisms that are used for stem cell maintenance. However, plant tumours are less frequent and are not as lethal as those in animals. We argue that fundamental differences between plant and animal development make it much more difficult for individual plant cells to escape communal controls.

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Figure 1: Plant tumours and tumour-like growths.
Figure 2: Rb pathway in plants.
Figure 3: MYB orthologues regulate mitotic gene expression.
Figure 4: Role of auxin, cytokinin and RBR in plant stem cell niches.


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The authors would like to thank H. Sakakibara (Riken Institute, Japan), R. Kahmann, (Max-Planck-Institut (MPI), Marburg, Germany) and R. Briddon (National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan) for supplying images of plants with pathogen-induced proliferative defects; and L. Hanley-Bowdoin, M. Ito, C. Lloyd and P. Wigge for critically reading the manuscript.

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A class of plant hormones (especially INDOLE-3-ACETIC ACID (IAA) and similar compounds) that control cell division, cell expansion and differentiation.


A population of stem cells that sustain the production of vascular tissues in higher plants. They allow the stem and the root to increase in diameter by accumulating vascular cells (which make up the bulk of tree trunks, for example).

Crown gall

A tumour caused by Agrobacterium and often found on the crown (the root–stem junction) of plants.


A group of adenine-related plant hormones that regulate cell division and differentiation.


A cycle of DNA replication without mitosis or cell division, resulting in increased nuclear DNA content.


The re-replication of DNA without an intervening mitosis. This is often associated with cell differentiation.


The seed tissue that surrounds, protects and provides nutrients for the embryo.


The multicellular haploid stage of the plant life cycle that produces the gametes. In flowering plants, the male gametophyte is known as pollen, and the female gametophyte is the embryo sac.


A group of single-stranded DNA viruses, characterized by gemiate caspid. They infect a wide range of plants and are usually vectored by insects.


A group of self-renewing, undifferentiated cells that sustain the production of new plant tissues.


Cell proliferation outside normal developmental control.


A cell layer that surrounds the central vascular cylinder of the stem and roots and that initiates the development of new lateral roots.

Stem cell niche

A region in a tissue where stem cells are maintained, includes cells that produce a short-range stem cell maintenance signal and the surrounding region where the signal is able to maintain stem cell identity. Although plants and animals use different signals to maintain stem cells, the maintenance of stem cells within restricted microenvironments is a comparable feature in both kingdoms.


One of the partners in a mutually beneficial relationship between two species.

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Doonan, J., Sablowski, R. Walls around tumours — why plants do not develop cancer. Nat Rev Cancer 10, 794–802 (2010). https://doi.org/10.1038/nrc2942

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