Effect of phosphorus supply on root traits of two Brassica oleracea L. genotypes

Pongrac, Paula; Castillo-Michel, Hiram; Herrera, J.R.; Hancock, Robert D.; Fischer, Sina; Kelemen, Mitja; Thompson, Jacqueline A.; Wright, Gladys; Likar, Matev�; Broadley, Martin R.; Vavpeti?, Primo�; Pelicon, Primo�; White, Philip J.

Abstract

BACKGROUND: Phosphorus (P) deficiency limits crop production worldwide. Crops differ in their ability to acquire and utilise the P available. The aim of this study was to determine root traits (root exudates, root system architecture (RSA), tissue-specific allocation of P, and gene expression in roots) that (a) play a role in P-use efficiency and (b) contribute to large shoot zinc (Zn) concentration in Brassica oleracea. RESULTS: Two B. oleracea accessions (var. sabellica C6, a kale, and var. italica F103, a broccoli) were grown in a hydroponic system or in a high-throughput-root phenotyping (HTRP) system where they received Low P (0.025 mM) or High P (0.25 mM) supply for 2weeks. In hydroponics, root and shoot P and Zn concentrations were measured, root exudates were profiled using both Fourier-Transform-Infrared spectroscopy and gas-chromatography-mass spectrometry and previously published RNAseq data from roots was re-examined. In HTRP experiments, RSA (main and lateral root number and lateral root length) was assessed and the tissue-specific distribution of P was determined using micro-particle-induced-X-ray emission. The C6 accession had greater root and shoot biomass than the F103 accession, but the latter had a larger shoot P concentration than the C6 accession, regardless of the P supply in the hydroponic system. The F103 accession had a larger shoot Zn concentration than the C6 accession in the High P treatment. Although the F103 accession had a larger number of lateral roots, which were also longer than in the C6 accession, the C6 accession released a larger quantity and number of polar compounds than the F103 accession. A larger number of P-responsive genes were found in the Low P treatment in roots of the F103 accession than in roots of the C6 accession. Expression of genes linked with "phosphate starvation" was up-regulated, while those linked with iron homeostasis were down-regulated in the Low P treatment. CONCLUSIONS: The results illustrate large within-species variability in root acclimatory responses to P supply in the composition of root exudates, RSA and gene expression, but not in P distribution in root cross sections, enabling P sufficiency in the two B. oleracea accessions studied.

Citation

Pongrac, P., Castillo-Michel, H., Herrera, J., Hancock, R. D., Fischer, S., Kelemen, M., Thompson, J. A., Wright, G., Likar, M., Broadley, M. R., Vavpetič, P., Pelicon, P., & White, P. J. (2020). Effect of phosphorus supply on root traits of two Brassica oleracea L. genotypes. BMC Plant Biology, 20, Article 368. https://doi.org/10.1186/s12870-020-02558-2

• Journal Article Type: Article
• Acceptance Date: May 26, 2020
• Online Publication Date: Aug 5, 2020
• Publication Date: Aug 5, 2020
• Deposit Date: May 27, 2020
• Publicly Available Date: Aug 18, 2020
• Journal: BMC Plant Biology
• Electronic ISSN: 1471-2229
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 20
• Article Number: 368
• DOI: https://doi.org/10.1186/s12870-020-02558-2
• Keywords: Plant Science
• Public URL: https://nottingham-repository.worktribe.com/output/4518727
• Publisher URL: https://link.springer.com/article/10.1186%2Fs12870-020-02558-2