Induced carbon reallocation and compensatory growth as root herbivore tolerance mechanisms.
Upon attack by leaf herbivores, many plants reallocate photoassimilates below ground. However, little is known about how plants respond when the roots themselves come under attack. We investigated induced resource allocation in maize plants that are infested by the larvae Western corn rootworm Diabrotica virgifera virgifera. Using radioactive (11) CO(2), we demonstrate that root-attacked maize plants allocate more new (11) C carbon from source leaves to stems, but not to roots. Reduced meristematic activity and reduced invertase activity in attacked maize root systems are identified as possible drivers of this shoot reallocation response. The increased allocation of photoassimilates to stems is shown to be associated with a marked thickening of these tissues and increased growth of stem-borne crown roots. A strong quantitative correlation between stem thickness and root regrowth across different watering levels suggests that retaining photoassimilates in the shoots may help root-attacked plants to compensate for the loss of belowground tissues. Taken together, our results indicate that induced tolerance may be an important strategy of plants to withstand belowground attack. Furthermore, root herbivore-induced carbon reallocation needs to be taken into account when studying plant-mediated interactions between herbivores.
Root-Herbivore Interactions Group, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany; Departments of 2Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745, Jena, Germany.
Christelle A M
CA
Robert
Richard A
RA
Ferrieri
Stefanie
S
Schirmer
Benjamin A
BA
Babst
Michael J
MJ
Schueller
Ricardo A R
RA
Machado
Carla C M
CC
Arce
Bruce E
BE
Hibbard
Jonathan
J
Gershenzon
Ted C J
TC
Turlings
Matthias
M
Erb
D000222:Adaptation, Physiological; D000818:Animals; D018533:Biomass; D050260:Carbohydrate Metabolism; D002244:Carbon / Q000378:metabolism*; D001517:Coleoptera / Q000502:physiology*; D060434:Herbivory / Q000502:physiology*; D018519:Meristem / Q000502:physiology; D018517:Plant Roots / Q000254:growth & development / Q000502:physiology*; D018520:Plant Shoots / Q000502:physiology; D018547:Plant Stems / Q000502:physiology; D014867:Water; D003313:Zea mays / Q000469:parasitology* / Q000502:physiology; D043324:beta-Fructofuranosidase / Q000378:metabolism
D014867:Water; D002244:Carbon; D043324:beta-Fructofuranosidase
11CO2; Diabrotica virgifera; compensatory root growth; plant herbivore interactions