Details

Autor(en) / Beteiligte

• Agtuca, Beverly J
• Stopka, Sylwia A
• Tuleski, Thalita R
• do Amaral, Fernanda P
• Evans, Sterling
• Liu, Yang
• Xu, Dong
• Monteiro, Rose Adele
• Koppenaal, David W
• Paša-Tolić, Ljiljana
• Anderton, Christopher R
• Vertes, Akos
• Stacey, Gary

Titel

In-Situ Metabolomic Analysis of Setaria viridis Roots Colonized by Beneficial Endophytic Bacteria

Ist Teil von

• Molecular plant-microbe interactions, 2020-02, Vol.33 (2), p.272-283

Ort / Verlag

United States: American Phytopathological Society

Erscheinungsjahr

2020

Quelle

MEDLINE

Beschreibungen/Notizen

• Over the past decades, crop yields have risen in parallel with increasing use of fossil fuel-derived nitrogen (N) fertilizers but with concomitant negative impacts on climate and water resources. There is a need for more sustainable agricultural practices, and biological nitrogen fixation (BNF) could be part of the solution. A variety of nitrogen-fixing, epiphytic, and endophytic plant growth-promoting bacteria (PGPB) are known to stimulate plant growth. However, compared with the rhizobium-legume symbiosis, little mechanistic information is available as to how PGPB affect plant metabolism. Therefore, we investigated the metabolic changes in roots of the model grass species upon endophytic colonization by SmR1 (fix ) or a fix mutant strain (SmR54) compared with uninoculated roots. Endophytic colonization of the root is highly localized and, hence, analysis of whole-root segments dilutes the metabolic signature of those few cells impacted by the bacteria. Therefore, we utilized in-situ laser ablation electrospray ionization mass spectrometry to sample only those root segments at or adjacent to the sites of bacterial colonization. Metabolites involved in purine, zeatin, and riboflavin pathways were significantly more abundant in inoculated plants, while metabolites indicative of nitrogen, starch, and sucrose metabolism were reduced in roots inoculated with the fix strain or uninoculated, presumably due to N limitation. Interestingly, compounds, involved in indole-alkaloid biosynthesis were more abundant in the roots colonized by the fix strain, perhaps reflecting a plant defense response.