Martin Hülskamp, University of Cologne, Cologne, Germany
Swen Schellmann, University of Cologne, Cologne, Germany
Published online: March 2009
DOI: 10.1002/9780470015902.a0002071.pub2
A ‘trichome’ (or hair) is an outgrowth derived from the shoot or root epidermis of a plant. Form and distribution of trichomes differ between plant species or genera, but molecular work reveals common regulatory pathway for development of different trichome types within the same plant species and possibly also across plant species.
Keywords: trichomes; root hairs; patterning
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Figure 1. (a) Rosette of a young Arabidopsis thaliana plant. Note the regular distribution of leaf trichomes. (b) Unicellular branched trichome of Arabis alpina. (c) Multicellular unbranched trichome of Tricyrtis hirta. (d) Glandular trichome of Pelargonium zonale. (e) Root hair of A. thaliana.
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Figure 2. Genetic model for the selection of a trichome and root hair cells in Arabidopsis. Bottom: Initially, both cells are equivalent. They express the bHLH, the R2R3 MYB factor, the WD40 protein, which activate GL2 and the R3 MYB factor. Owing to movement of the R3 MYB factor the cells compete with each other. Middle: Owing to small fluctuations the system becomes biased; here the right cell becomes specialized as indicated by its blue colour. In this cell the bHLH/R2R3MYB/WD40 complex activates GL2 and the R3 MYB factor which moves into the neighbouring cell where it replaces the R2R3 MYB factor rendering the complex inactive. Upper pictures: the specizalized cells (blue) develop into trichomes (left) and nonroot hair cells (right). Note that trichomes distribution is without reference to any other leaf structure whereas root hair position is biased such that root hairs form above clefts of cortex cells.
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| References | |
| Bernhardt C, Lee MM, Gonzalez A et al. (2003) The bHLH genes GLABRA3 (GL3) and ENHANCER OF GLABRA3 (EGL3) specify epidermal cell fate in the Arabidopsis root. Development 130: 6431–6439. | |
| Bernhardt C, Zhao M, Gonzalez A, Lloyd A and Schiefelbein J (2005) The bHLH genes GL3 and EGL3 participate in an intercellular regulatory circuit that controls cell patterning in the Arabidopsis root epidermis. Development 132: 291–298. | |
| Chien JC and Sussex IM (1996) Differential regulation of trichome formation on the adaxial and abaxial leaf surfaces by gibberellins and photoperiod in Arabidopsis thaliana (L.) Heynh. Plant Physiology 111: 1321–1328. | |
| Cristina MD, Sessa G, Dolan L et al. (1996) The Arabidopsis Athb-10 (GLABRA2) is an HD-Zip protein required for regulation of root hair development. Plant Journal 10: 393–402. | |
| Dolan L, Duckett CM, Grierson C et al. (1994) Clonal relationships and cell patterning in the root epidermis of Arabidopsis. Development 120: 2465–2474. | |
| Esch JJ, Chen M, Sanders M et al. (2003) A contradictory GLABRA3 allele helps define gene interactions controlling trichome development in Arabidopsis. Development 130: 5885–5894. | |
| Galway ME, Masucci JD, Lloyd AM et al. (1994) The TTG gene is required to specify epidermal cell fate and cell patterning in the Arabidopsis root. Developmental Biology 166: 740–754. | |
| Gan Y, Kumimoto R, Liu C et al. (2006) GLABROUS INFLORESCENCE STEMS modulates the regulation by gibberellins of epidermal differentiation and shoot maturation in Arabidopsis. Plant Cell 18: 1383–1395. | |
| Gan Y, Liu C, Yu H and Broun P (2007) Integration of cytokinin and gibberellin signalling by Arabidopsis transcription factors GIS, ZFP8 and GIS2 in the regulation of epidermal cell fate. Development 134: 2073–2081. | |
| Greenboim-Wainberg Y, Maymon I, Borochov R et al. (2005) Cross talk between gibberellin and cytokinin: the Arabidopsis GA response inhibitor SPINDLY plays a positive role in cytokinin signaling. Plant Cell 17: 92–102. | |
| Hulskamp M (2004) Plant trichomes: a model for cell differentiation. Nature Reviews. Molecular Cell Biology 5: 471–480. | |
| Hulskamp M, Misera S and Jürgens G (1994) Genetic dissection of trichome cell development in Arabidopsis. Cell 76: 555–566. | |
| Kirik V, Lee MM, Wester K et al. (2005) Functional diversification of MYB23 and GL1 genes in trichome morphogenesis and initiation. Development 132: 1477–1485. | |
| Kirik V, Schnittger A, Radchuk V et al. (2001) Ectopic expression of the Arabidopsis AtMYB23 gene induces differentiation of trichome cells. Developmental Biology 235: 366–377. | |
| Kwak SH, Shen R and Schiefelbein J (2005) Positional signaling mediated by a receptor-like kinase in Arabidopsis. Science 307: 1111–1113. | |
| Larkin JC, Young N, Prigge M and Marks MD (1996) The control of trichome spacing and number in Arabidopsis. Development 122: 997–1005. | |
| Lee MM and Schiefelbein J (1999) WEREWOLF, a MYB-related protein in Arabidopsis, is a position-dependent regulator of epidermal cell patterning. Cell 99: 473–483. | |
| Lee MM and Schiefelbein J (2002) Cell patterning in the Arabidopsis root epidermis determined by lateral inhibition with feedback. Plant Cell 14: 611–618. | |
| Masucci JD, Rerie WG, Foreman DR et al. (1996) The homeobox gene GLABRA 2 is required for position-dependent cell differentiation in the root epidermis of Arabidopsis thaliana. Development 122: 1253–1260. | |
| book Meinhardt H (1982) Models of Biological Pattern Formation. London, New York, Paris: Academic Press. | |
| Oppenheimer DG, Herman PL, Sivakumaran S, Esch J and Marks MD (1991) A myb gene required for leaf trichome differentiation in Arabidopsis is expressed in stipules. Cell 67: 483–493. | |
| Payne CT, Zhang F and Lloyd AM (2000) GL3 encodes a bHLH protein that regulates trichome development in Arabidopsis through interaction with GL1 and TTG1. Genetics 156: 1349–1362. | |
| Pesch M and Hulskamp M (2004) Creating a two-dimensional pattern de novo during Arabidopsis trichome and root hair initiation. Current Opinion in Genetics & Development 14: 422–427. | |
| Rahman A, Hosokawa S, Oono Y et al. (2002) Auxin and ethylene response interactions during Arabidopsis root hair development dissected by auxin influx modulators. Plant Physiology 130: 1908–1917. | |
| Rerie WG, Feldmann KA and Marks MD (1994) The glabra 2 gene encodes a homeo domain protein required for normal trichome development in Arabidobsis. Genes and Development 8: 1388–1399. | |
| Schellmann S, Schnittger A, Kirik V et al. (2002) TRIPTYCHON and CAPRICE mediate lateral inhibition during trichome and root hair patterning in Arabidopsis. EMBO Journal 21: 5036–5046. | |
| Schnittger A, Folkers U, Schwab B, Jürgens G and Hulskamp M (1999) Generation of a spacing pattern: the role of TRIPTYCHON in trichome patterning in Arabidopsis. Plant Cell 11: 1105–1116. | |
| Schnittger A, Jurgens G and Hulskamp M (1998) Tissue layer and organ specificity of trichome formation are regulated by GLABRA1 and TRIPTYCHON in Arabidopsis. Development 125: 2283–2289. | |
| Serna L and Martin C (2006) Trichomes: different regulatory networks lead to convergent structures. Trends in Plant Science 11: 274–280. | |
| Szymanski DB and Marks MD (1998) GLABROUS1 overexpression and TRIPTYCHON alter the cell cycle and trichome cell fate in Arabidopsis. Plant Cell 10: 2047–2062. | |
| Tanimoto M, Roberts K and Dolan L (1995) Ethylene is a positive regulator of root hair development in Arabidopsis thaliana. Plant Journal 8: 101–106. | |
| Telfer A, Bollman KM and Poethig RS (1997) Phase change and the regulation of trichome distribution in Arabidopsis thaliana. Development 124: 645–654. | |
| Traw MB and Bergelson J (2003) Interactive effects of jasmonic acid, salicylic acid, and gibberellin on induction of trichomes in Arabidopsis. Plant Physiology 133: 1367–1375. | |
| book Uphof JCT (1962) Plant Hairs. Berlin: Gebr. Bornträger. | |
| Wada T, Kurata T, Tominaga R et al. (2002) Role of a positive regulator of root hair development, CAPRICE, in Arabidopsis root epidermal cell differentiation. Development 129: 5409–5419. | |
| Wada T, Tachibana T, Shimura Y and Okada K (1997) Epidermal cell differentiation in Arabidopsis determined by a Myb homolog, CPC. Science 277: 1113–1116. | |
| Wagner GJ, Wang E and Shepherd RW (2004) New approaches for studying and exploiting an old protuberance, the plant trichome. Annals of Botany (London) 93: 3–11. | |
| Walker AR, Davison PA, Bolognesi-Winfield AC et al. (1999) The TRANSPARENT TESTA GLABRA1 locus, which regulates trichome differentiation and anthocyanin biosynthesis in Arabidopsis, encodes a WD40 repeat protein. Plant Cell 11: 1337–1349. | |
| Zhang F, Gonzalez A, Zhao M, Payne CT and Lloyd A (2003) A network of redundant bHLH proteins functions in all TTG1-dependent pathways of Arabidopsis. Development 130: 4859–4869. | |
| Further Reading | |
| Hulskamp M (2004) Plant trichomes: a model for cell differentiation. Nature Reviews. Molecular Cell Biology 5: 471–480. | |
| Ishida T, Kurata T, Okada K and Wada T (2008) A genetic regulatory network in the development of trichomes and root hairs. Annual Review of Plant Biology 59: 365–386. | |
| Pesch M and Hulskamp M (2004) Creating a two-dimensional pattern de novo during Arabidopsis trichome and root hair initiation. Current Opinion in Genetics & Development 14: 422–427. | |
| Serna L and Martin C (2006) Trichomes: different regulatory networks lead to convergent structures. Trends in Plant Science 11(6): 274–280. | |
| book Uphof JCT (1962) Plant Hairs. Berlin: Gebr. Bornträger. | |
| Wagner GJ, Wang E and Shepherd RW (2004) New approaches for studying and exploiting an old protuberance, the plant trichome. Annals of Botany 93: 3–11. | |
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