Branch out

There are some papers published in Nature volume 455 in August 2008 are quite interested to me. A new class of plant hormones, strigolactones or terpenoids, which may stimulate seed germination, act as a signal of symbiotic interaction with the arbuscular mycorrhizal fungi, and inhibit shoot and root branching.

I can not post the full text on here due to copyright, but you can use any university's computer to access it on www.nature.com. I believe almost all university has subscribed e-journal of Nature.

Plant biology: Hormones branch out, Nature 455:176, Harry Klee.
Evidence points to the existence of a hitherto uncharacterized type of hormone that controls different aspects of plant growth and interaction. The hunt for that hormone is heating up.

Strigolactone inhibition of shoot branching, Nature 455:189, Victoria Gomez-Roldan et al.
Shoot branching is regulated by hormones. Branching mutants in several plant species suggests the existence of a plant hormone that is released from the roots and prevents excessive shoot branching. This paper reports on one of two studies that show that a class of chemical compounds called strigolactones found in root exudates are reduced in the branching mutants and that external application of these chemicals inhibits shoot branching in the mutants. It is proposed that strigolactones or related metabolites are the sought after class of hormones.

Inhibition of shoot branching by new terpenoid plant hormones, Nature 455:195, Mikihisa Umehara et al.
Shoot branching is regulated by hormones. Branching mutants in several plant species suggests the existence of a plant hormone that is released from the roots and prevents excessive shoot branching. This paper reports on one of two studies that show that a class of chemical compounds called strigolactones found in root exudates are reduced in the branching mutants and that external application of these chemicals inhibits shoot branching in the mutants. It is proposed that strigolactones or related metabolites are the sought after class of hormones.
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Here are earlier papers:

Dodd, I. C., Ferguson, B. J. & Beveridge, C. A. Apical wilting and petiole xylem vessel diameter of the rms2 branching mutant of pea are shoot controlled and independent of a long-distance signal regulating branching. Plant Cell Physiol. 49(5):791–800 (2008).

Lopez-Raez, J. A. et al. Tomato strigolactones are derived from carotenoids and their biosynthesis is promoted by phosphate starvation. New Phytol. 178(4):863–874 (2008).

Mouchel, C. F. & Leyser, O. Novel phytohormones involved in long-range signaling. Curr. Opin. Plant Biol. 10(5):473–476 (2007).

Auldridge, M. E. et al. Characterization of three members of the Arabidopsis carotenoid cleavage dioxygenase family demonstrates the divergent roles of this multifunctional enzyme family. Plant J. 45(6):982–993 (2006).

Dun, E. A., Ferguson, B. J. & Beveridge, C. A. Apical dominance and shoot branching. Divergent opinions or divergent mechanisms? Plant Physiol. 142(3):812–819 (2006).

JXenie Johnson, Tanya Brcich, Elizabeth A. Dun, Magali Goussot, Karine Haurogné, Christine A. Beveridge, and Catherine Rameau, Branching genes are conserved across species. Genes controlling a novel signal in pea are coregulated by other long-distance signals. Plant Physiol. 142(3):1014–1026 (2006).

Beveridge, C. A. Axillary bud outgrowth: sending a message. Curr. Opin. Plant Biol. 9(1):35–40 (2006).

Booker J, Sieberer T, Wright W, Williamson L, Willett B, Stirnberg P, Turnbull C, Srinivasan M, Goddard P, Leyser O: MAX1 encodes a cytochrome P450 family member that acts downstream of MAX3/4 to produce a carotenoid-derived branch-inhibiting hormone. Dev Cell, 8:443-449 (2005).

Foo E, Bullier E, Goussot M, Foucher F, Rameau C, Beveridge C: The branching gene RAMOSUS1 mediates interactions among two novel signals and auxin in pea. Plant Cell 2005, 17(2):464-474 (2005).

Morris SE, Cox MCH, Ross JJ, Krisantini S, Beveridge CA: Auxin dynamics after decapitation are not correlated with the initial growth of axillary buds. Plant Physiol, 138(3):1665-1672 (2005).

Nordstrom A, Tartowski P, Tarkowska D, Norbaek R, Astot C, Dolezal K, Sandberg G: Auxin regulation of cytokinin biosynthesis in Arabidopsis thaliana: a factor of potential importance for auxin-cytokinin-regulated development. PNAS, 101(21):8039-8044 (2004).

Dodd IC, Ngo C, Turnbull CGN, Beveridge CA: Effects of nitrogen supply on xylem cytokinin delivery, transpiration and leaf expansion of pea genotypes differing in xylem-cytokinin concentration. Funct Plant Biol, 31:903-911 (2004).

Beveridge CA, Weller JL, Singer SR, Hofer JMI: Axillary meristem development. Budding relationships between networks controlling flowering, branching and photoperiod responsiveness. Plant Physiol, 131(3):927-934 (2003).



Horvath DP, Anderson JV, Chao WS, Foley MR: Knowing when to grow: signals regulating bud dormancy. Trends Plant Sci 8:534-540 (2003).

Sorefan K, Booker J, Haurogne´ K, Goussot M, Bainbridge K, Foo E, Chatfield S, Ward S, Beveridge C, Rameau C, Leyser O: MAX4 and RMS1 are orthologous dioxygenase-like genes that regulate shoot branching in Arabidopsis and pea. Genes Dev, 17:1469-1474. 11 (2003).



Morris SE, Beveridge CA, Murfet IC, Prioul S, Rameau C: The basal branching pea mutant rms7-1. Pisum Genet 2003, 35:10-14 (2003).

Rameau C, Murfet IC, Laucou V, Floyd RS, Morris SE, Beveridge CA: Pea rms6 mutants exhibit increased basal branching. Physiol Plant, 115:458-467 (2002).

Turnbull, C. G., Booker, J. P. & Leyser, H. M. Micrografting techniques for testing long-distance signalling in Arabidopsis. Plant J. 32(2):255–262 (2002).

Foo, E., Turnbull, C. G. & Beveridge, C. A. Long-distance signaling and the control of branching in the rms1 mutant of pea. Plant Physiol. 126(1):203–209 (2001).

Morris, S. E., Turnbull, C. G., Murfet, I. C. & Beveridge, C. A. Mutational analysis of branching in pea. Evidence that Rms1 and Rms5 regulate the same novel signal. Plant Physiol. 126(3):1205–1213 (2001).

Beveridge, C. A., Symons, G. M. & Turnbull, C. G. N. Auxin inhibition of decapitation-induced branching is dependent on graft-transmissible signals regulated by genes Rms1 and Rms2. Plant Physiol. 123(2):689–697 (2000).

Beveridge CA: Long-distance signalling and a mutational analysis of branching in pea. Plant Growth Reg, 32:193-203 (2000).

Beveridge CA, Murfet IC, Kerhoas L, Sotta B, Miginiac E, Rameau C: The shoot controls zeatin riboside export from pea roots: evidence from the branching mutant rms4. Plant J, 11(2):339-345 (1997).

Beveridge, C. A., Symons, G. M., Murfet, I. C., Ross, J. J. & Rameau, C. The rms1 mutant of pea has elevated indole-3-acetic acid levels and reduced root-sap zeatin riboside content but increased branching controlled by graft transmissible signal(s). Plant Physiol. 115(3):1251–1258 (1997).

Kenrick, P. & Crane, P. R. The origin and early evolution of plants on land. Nature 389(6646):33–39 (1997).

Beveridge, C. A., Ross, J. J. & Murfet, I. C. Branching in pea (action of genes Rms3 and Rms4). Plant Physiol. 110(3):859–865 (1996).

Beveridge CA, Ross JJ, Murfet IC: Branching mutant rms-2 in Pisum sativum. Grafting studies and endogenous indole-3-acetic acid levels. Plant Physiol, 104(3):953-959 (1994).