Ustilago maydis Infection Strongly Alters Organic Nitrogen Allocation in Maize and Stimulates Productivity of Systemic Source Leaves

Journal article


Publication Details

Author(s): Horst R, Doehlemann G, Wahl R, Hofmann J, Schmiedl A, Kahmann R, Kaemper J, Sonnewald U, Voll L
Journal: Plant Physiology
Publisher: AMER SOC PLANT BIOLOGISTS
Publication year: 2010
Volume: 152
Journal issue: 1
Pages range: 293-308
ISSN: 0032-0889


Abstract


The basidiomycete Ustilago maydis is the causal agent of corn smut disease and induces tumor formation during biotrophic growth in its host maize (Zea mays). We have conducted a combined metabolome and transcriptome survey of infected leaves between 1 d post infection (dpi) and 8 dpi, representing infected leaf primordia and fully developed tumors, respectively. At 4 and 8 dpi, we observed a substantial increase in contents of the nitrogen-rich amino acids glutamine and asparagine, while the activities of enzymes involved in primary nitrogen assimilation and the content of ammonia and nitrate were reduced by 50% in tumors compared with mock controls. Employing stable isotope labeling, we could demonstrate that U. maydis-induced tumors show a reduced assimilation of soil-derived (NO3-)-N-15 and represent strong sinks for nitrogen. Specific labeling of the free amino acid pool of systemic source leaves with [N-15] urea revealed an increased import of organic nitrogen from systemic leaves to tumor tissue, indicating that organic nitrogen provision supports the formation of U. maydis-induced tumors. In turn, amino acid export from systemic source leaves was doubled in infected plants. The analysis of the phloem amino acid pool revealed that glutamine and asparagine are not transported to the tumor tissue, although these two amino acids were found to accumulate within the tumor. Photosynthesis was increased and senescence was delayed in systemic source leaves upon tumor development on infected plants, indicating that the elevated sink demand for nitrogen could determine photosynthetic rates in source leaves.



FAU Authors / FAU Editors

Hofmann, Jörg Dr.
Lehrstuhl für Biochemie
Schmiedl, Alfred
Lehrstuhl für Biochemie
Sonnewald, Uwe Prof. Dr.
Lehrstuhl für Biochemie
Voll, Lars PD Dr.
Lehrstuhl für Biochemie


External institutions with authors

Karlsruhe Institute of Technology (KIT)
Max-Planck-Institut für Terrestrische Mikrobiologie / Max Planck Institute for Terrestrial Microbiology


How to cite

APA:
Horst, R., Doehlemann, G., Wahl, R., Hofmann, J., Schmiedl, A., Kahmann, R.,... Voll, L. (2010). Ustilago maydis Infection Strongly Alters Organic Nitrogen Allocation in Maize and Stimulates Productivity of Systemic Source Leaves. Plant Physiology, 152(1), 293-308. https://dx.doi.org/10.1104/pp.109.147702

MLA:
Horst, Robin, et al. "Ustilago maydis Infection Strongly Alters Organic Nitrogen Allocation in Maize and Stimulates Productivity of Systemic Source Leaves." Plant Physiology 152.1 (2010): 293-308.

BibTeX: 

Last updated on 2018-10-08 at 21:30

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