Linkohr, B I, Williamson, L C, Fitter, A H and Leyser, H M O (2002) Nitrate and phosphate availability and distribution have different effects on root system architecture of Arabidopsis. Plant Journal. pp. 751-760. ISSN 0960-7412Full text available as:
Plant root systems can respond to nutrient availability and distribution by changing the three-dimensional deployment of their roots: their root system architecture (RSA). We have compared RSA in homogeneous and heterogeneous nitrate and phosphate supply in Arabidopsis. Changes in nitrate and phosphate availability were found to have contrasting effects on primary root length and lateral root density, but similar effects on lateral root length. Relative to shoot dry weight (DW), primary root length decreased with increasing nitrate availability, while it increased with increasing phosphate supply. Lateral root density remained constant across a range of nitrate supplies, but decreased with increasing phosphate supply. In contrast, lateral root elongation was suppressed both by high nitrate and high phosphate supplies. Local supplies of high nitrate or phosphate in a patch also had different effects. Primary root growth was not affected by a high nitrate patch, but growth through a high phosphate patch reduced primary root growth after the root left the patch. A high nitrate patch induced an increase in lateral root density in the patch, whereas lateral root density was unaffected by a high phosphate patch. However, both phosphate- and nitrate-rich patches induced lateral root elongation in the patch and suppressed it outside the patch. This co-ordinated response of lateral roots also occurs in soil-grown plants exposed to a nutrient-rich patch. The auxin-resistant mutants axr1, axr4 and aux1 all showed the wild-type lateral root elongation responses to a nitrate-rich patch, suggesting that auxin is not required for this response.
|Copyright, Publisher and Additional Information:||© 2002 Blackwell Science Ltd. This is an electronic version of an article published in Plant Journal: complete citation information for the final version of the paper, as published in the print edition of Plant Journal, is available on the Blackwell Synergy online delivery service, accessible via the journal's website at www.blackwellpublishing.com/journal.asp?ref=0960-7412 or www.blackwell-synergy.com|
|Keywords:||root system architecture (RSA), nitrate, phosphate, homogeneity, heterogeneity, auxin, COMPENSATORY INCREASES, GROWTH, AUXIN, THALIANA, NITROGEN, BARLEY, PROLIFERATION, MUTATION, PLANTS, RESPONSES|
|Academic Units:||The University of York > Biology (York)|
|Depositing User:||Repository Officer|
|Date Deposited:||25 May 2005|
|Last Modified:||17 Oct 2013 14:33|