Temporal changes in allocation and partitioning of new carbon as (11)C elicited by simulated herbivory suggest that roots shape aboveground responses in Arabidopsis.
Using the short-lived isotope (11)C (t(1/2) = 20.4 min) as (11)CO(2), we captured temporal changes in whole-plant carbon movement and partitioning of recently fixed carbon into primary and secondary metabolites in a time course (2, 6, and 24 h) following simulated herbivory with the well-known defense elicitor methyl jasmonate (MeJA) to young leaves of Arabidopsis (Arabidopsis thaliana). Both (11)CO(2) fixation and (11)C-photosynthate export from the labeled source leaf increased rapidly (2 h) following MeJA treatment relative to controls, with preferential allocation of radiolabeled resources belowground. At the same time, (11)C-photosynthate remaining in the aboveground sink tissues showed preferential allocation to MeJA-treated, young leaves, where it was incorporated into (11)C-cinnamic acid. By 24 h, resource allocation toward roots returned to control levels, while allocation to the young leaves increased. This corresponded to an increase in invertase activity and the accumulation of phenolic compounds, particularly anthocyanins, in young leaves. Induction of phenolics was suppressed in sucrose transporter mutant plants (suc2-1), indicating that this phenomenon may be controlled, in part, by phloem loading at source leaves. However, when plant roots were chilled to 5°C to disrupt carbon flow between above- and belowground tissues, source leaves failed to allocate resources belowground or toward damaged leaves following wounding and MeJA treatment to young leaves, suggesting that roots may play an integral role in controlling how plants respond defensively aboveground.
University of Missouri, Division of Plant Sciences, Bond Life Sciences Center, Columbia, Missouri 65211, USA. aferrieri@ice.mpg.de
Abigail P
AP
Ferrieri
Beverly
B
Agtuca
Heidi M
HM
Appel
Richard A
RA
Ferrieri
Jack C
JC
Schultz
D000085:Acetates / Q000494:pharmacology; D000818:Animals; D000872:Anthocyanins / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000469:parasitology; D001692:Biological Transport / Q000187:drug effects / Q000235:genetics; D002245:Carbon Dioxide / Q000378:metabolism*; D002250:Carbon Radioisotopes; D002934:Cinnamates / Q000378:metabolism; D003517:Cyclopentanes / Q000494:pharmacology; D060434:Herbivory / Q000502:physiology; D006790:Host-Parasite Interactions / Q000187:drug effects; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D054883:Oxylipins / Q000494:pharmacology; D019800:Phenol / Q000378:metabolism; D052585:Phloem / Q000235:genetics / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism* / Q000469:parasitology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism* / Q000469:parasitology; D013997:Time Factors; D043324:beta-Fructofuranosidase / Q000378:metabolism
D000085:Acetates; D000872:Anthocyanins; D002250:Carbon Radioisotopes; D002934:Cinnamates; D003517:Cyclopentanes; D026901:Membrane Transport Proteins; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; C078729:sucrose transport protein, plant; C029010:cinnamic acid; D002245:Carbon Dioxide; D019800:Phenol; C072239:methyl jasmonate; D043324:beta-Fructofuranosidase