The interaction of light quality and irradiance with gibberellins, cytokinins and auxin in regulating growth of Helianthus annuus hypocotyls

Plant, Cell and Environment - Tập 30 Số 2 - Trang 147-155 - 2007
Leonid V. Kurepin1, R. J. Neil Emery2, Richard P. Pharis1, David B. Dunger1
1Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada and
2Biology Department, Trent University, Peterborough, Ontario, Canada

Tóm tắt

ABSTRACTA reduced red to far‐red (R/FR) light ratio and low photosynthetically active radiation (PAR) irradiance are both strong signals for inducing etiolation growth of plant stems. Under natural field conditions, plants can be exposed to either a reduced R/FR ratio or lower PAR, or to a combination of both. We used Helianthus annuus L., the sunflower, to study the effect of reduced R/FR ratio, low PAR or their combination on hypocotyl elongation. To accomplish this, we attempted to uncouple light quality from light irradiance as factors controlling hypocotyl elongation. We measured alterations in the levels of endogenous gibberellins (GAs), cytokinins (CKs) and the auxin indole‐3‐acetic acid (IAA), and the effect of exogenous hormones on hypocotyl growth. As expected, both reduced R/FR ratio and lower PAR can significantly promote sunflower hypocotyl elongation when given separately. However, providing the reduced R/FR ratio at a low PAR resulted in the greatest hypocotyl growth, and this was accompanied by significantly higher levels of endogenous IAA, GA1, GA8, GA20 and of a wide range of CKs. Providing a reduced R/FR ratio under normal PAR also significantly increased growth and again gave significantly higher levels of endogenous IAA, GAs and CKs. However, only under the de‐etiolating influence of a normal R/FR ratio did lowering PAR significantly increase levels of GA1, GA8 and GA20. We thus conclude that light quality (e.g. the R/FR ratio) is the most important component of shade for controlling hypocotyl growth and elevated growth hormone content.

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Tài liệu tham khảo

10.1016/S1360-1385(99)01383-7

10.1126/science.247.4940.329

10.1111/j.1365-3040.1991.tb01371.x

10.1139/b96-093

10.1007/BF01160716

10.1104/pp.107.4.1075

10.1016/S0021-9673(02)00024-9

10.1104/pp.117.4.1515

10.1104/pp.123.4.1593

10.1016/S1360-1385(02)02228-8

10.1139/b05-049

10.1093/aob/mci165

Gaskin P., 1991, GC‐MS of the Gibberellins and Related Compounds. Methodology and a Library of Spectra

Gawronska H., 1995, Effects of low irradiance stress on gibberellin levels in pea seedlings, Plant and Cell Physiology, 36, 1361

Hedden P., 1987, Principles and Practice of Plant Hormone Analysis, 9

Hoagland D.R., 1950, The water‐culture method for growing plants without soil, California Agricultural Experiment Station Circular, 347, 1

10.1034/j.1399-3054.2002.1150313.x

10.1111/j.1365-3040.2005.01443.x

10.1111/j.1365-3040.2006.01512.x

10.1104/pp.122.3.621

10.1104/pp.95.4.1197

10.1007/s004250050510

10.1002/rcm.1290091016

10.1105/tpc.105.037796

10.1007/s00425-004-1421-4

10.1038/35036500

10.1046/j.1365-3040.1997.d01-104.x

10.1242/dev.126.19.4235

10.1104/pp.108.4.1423

10.1126/science.1065022

10.1023/A:1005906609158

10.1105/tpc.018978

10.1007/BF00392984

10.1104/pp.103.022665

10.1016/j.pbi.2005.07.007

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Thông tin xuất bản

Plant, Cell and Environment

Tập 30 Số 2

147-155

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