TY - JOUR
T1 - Reduction in root secondary growth as a strategy for phosphorus acquisition
AU - Strock, Christopher F.
AU - De La Riva, Laurie Morrow
AU - Lynch, Jonathan P.
N1 - Funding Information:
1This project was supported by the USAID Climate Resilient Beans Feed the Future Legume Innovation Laboratory and the National Institute of Food and Agriculture, U.S. Department of Agriculture, Hatch project 4582. 2 Current address: 221 Tyson Building, University Park, PA 16802. 3 Address correspondence to jpl4@psu.edu. The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Jonathan P. Lynch (jpl4@psu.edu). C.F.S. performed all of the experiments, analyzed the data, and wrote the article with contributions of all the authors; L.M.d.l.R. carried out the original screening and foundational research for these published data; J.P.L. conceived the hypotheses and supervised the design, experimentation, analysis, and reporting. [OPEN] Articles can be viewed without a subscription. www.plantphysiol.org/cgi/doi/10.1104/pp.17.01583
Publisher Copyright:
© 2018 American Society of Plant Biologists. All rights reserved.
PY - 2018/1
Y1 - 2018/1
N2 - We tested the hypothesis that reduced root secondary growth of dicotyledonous species improves phosphorus acquisition. Functional-structural modeling in SimRoot indicates that, in common bean (Phaseolus vulgaris), reduced root secondary growth reduces root metabolic costs, increases root length, improves phosphorus capture, and increases shoot biomass in lowphosphorus soil. Observations from the field and greenhouse confirm that, under phosphorus stress, resource allocation is shifted from secondary to primary root growth, genetic variation exists for this response, and reduced secondary growth improves phosphorus capture from low-phosphorus soil. Under low phosphorus in greenhouse mesocosms, genotypes with reduced secondary growth had 39% smaller root cross-sectional area, 60% less root respiration, 27% greater root length, 78% greater shoot phosphorus content, and 68% greater shoot mass than genotypes with advanced secondary growth. In the field under low phosphorus, these genotypes had 43% smaller root cross-sectional area, 32% greater root length, 58% greater shoot phosphorus content, and 80% greater shoot mass than genotypes with advanced secondary growth. Secondary growth eliminated arbuscular mycorrhizal associations as cortical tissue was destroyed. These results support the hypothesis that reduced root secondary growth is an adaptive response to low phosphorus availability and merits investigation as a potential breeding target.
AB - We tested the hypothesis that reduced root secondary growth of dicotyledonous species improves phosphorus acquisition. Functional-structural modeling in SimRoot indicates that, in common bean (Phaseolus vulgaris), reduced root secondary growth reduces root metabolic costs, increases root length, improves phosphorus capture, and increases shoot biomass in lowphosphorus soil. Observations from the field and greenhouse confirm that, under phosphorus stress, resource allocation is shifted from secondary to primary root growth, genetic variation exists for this response, and reduced secondary growth improves phosphorus capture from low-phosphorus soil. Under low phosphorus in greenhouse mesocosms, genotypes with reduced secondary growth had 39% smaller root cross-sectional area, 60% less root respiration, 27% greater root length, 78% greater shoot phosphorus content, and 68% greater shoot mass than genotypes with advanced secondary growth. In the field under low phosphorus, these genotypes had 43% smaller root cross-sectional area, 32% greater root length, 58% greater shoot phosphorus content, and 80% greater shoot mass than genotypes with advanced secondary growth. Secondary growth eliminated arbuscular mycorrhizal associations as cortical tissue was destroyed. These results support the hypothesis that reduced root secondary growth is an adaptive response to low phosphorus availability and merits investigation as a potential breeding target.
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U2 - 10.1104/pp.17.01583
DO - 10.1104/pp.17.01583
M3 - Article
C2 - 29118249
AN - SCOPUS:85040691506
SN - 0032-0889
VL - 176
SP - 691
EP - 703
JO - Plant physiology
JF - Plant physiology
IS - 1
ER -