Jasmonic acid signalling and herbivore resistance traits constrain regrowth after herbivore attack in <i> Nicotiana attenuata</i>

Zavala, Jorge A.; Baldwin, Ian Thomas

doi:10.1111/j.1365-3040.2006.01551.x

Cited by 56 publications

(49 citation statements)

References 54 publications

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“…MeJA-mediated IAA synthesis may be critical for the proper regulation of plant growth and development under biotic stress. Indeed, a recent study in insect-attacked tobacco (Nicotiana tabacum) plants suggests that JA signaling suppresses regrowth and contributes to apical dominance, a role expected from auxin (Zavala and Baldwin, 2006). A similar role for auxin was also proposed for ET-mediated inhibition of root elongation (Rahman et al, 2001;Stepanova et al, 2005).…”

Section: Discussionmentioning

confidence: 85%

MYC2 Differentially Modulates Diverse Jasmonate-Dependent Functions inArabidopsis

et al. 2007

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The Arabidopsis thaliana basic helix-loop-helix Leu zipper transcription factor (TF) MYC2/JIN1 differentially regulates jasmonate (JA)-responsive pathogen defense (e.g., PDF1.2) and wound response (e.g., VSP) genes. In this study, genomewide transcriptional profiling of wild type and mutant myc2/jin1 plants followed by functional analyses has revealed new roles for MYC2 in the modulation of diverse JA functions. We found that MYC2 negatively regulates Trp and Trp-derived secondary metabolism such as indole glucosinolate biosynthesis during JA signaling. Furthermore, MYC2 positively regulates JA-mediated resistance to insect pests, such as Helicoverpa armigera, and tolerance to oxidative stress, possibly via enhanced ascorbate redox cycling and flavonoid biosynthesis. Analyses of MYC2 cis binding elements and expression of MYC2-regulated genes in T-DNA insertion lines of a subset of MYC2-regulated TFs suggested that MYC2 might modulate JA responses via differential regulation of an intermediate spectrum of TFs with activating or repressing roles in JA signaling. MYC2 also negatively regulates its own expression, and this may be one of the mechanisms used in fine-tuning JA signaling. Overall, these results provide new insights into the function of MYC2 and the transcriptional coordination of the JA signaling pathway.

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Section: Discussionmentioning

confidence: 85%

MYC2 Differentially Modulates Diverse Jasmonate-Dependent Functions inArabidopsis

et al. 2007

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“…Moreover, a well-known attack-triggered growth response in Arabidopsis is to produce leaves with reduced petiole length, a response that depends on the activity of the jasmonate pathway (18,19). It is well known that the density of defensive structures (such as spines and trichomes) in plants can be controlled through attack-stimulated activity of the jasmonate pathway (20,21), and jasmonate-slowed growth may allow resource diversion to defense (22). Our observations with isopods now suggest that some of the changes commonly observed in response to attack (e.g., production of leaves with short petioles) might specifically affect plant architecture so as to reduce the vulnerability of potential weak spots to opportunistic attackers.…”

Section: Insects and Isopod Crustaceans Can Prey On Arabidopsis Seed mentioning

confidence: 99%

Detritivorous crustaceans become herbivores on jasmonate-deficient plants

Farmer

Dubugnon

2009

Proc. Natl. Acad. Sci. U.S.A.

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The jasmonate signal pathway is known to control defenses against herbivores, such as leaf eaters (folivores). Does the reach of the pathway extend to defense against other types of animal? Among the arthropods attracted to seed baits placed below flowering Arabidopsis thaliana plants are 2 largely nocturnal isopod crustaceans generally considered as detritivores: Porcellio scaber and Armadillidium vulgare. Parallel laboratory experiments identified the isopods as being capable of predation on intact plants. Isopod feeding was strongly facilitated in jasmonate-deficient Arabidopsis and rice plants. The feeding activity of isopods revealed potentially detritivore-sensitive, jasmonate-protected Achilles' heels in these architecturally different plants (petioles and inflorescence stems in Arabidopsis, and lower stem and mesocotyl in rice). The work addresses the question of what stops 2 detritivores from attacking living plants and provides evidence that it is, in part, the jasmonate signal pathway. Furthermore, senescent leaves from an Arabidopsis jasmonate mutant were consumed more rapidly than senescent wild-type leaves, suggesting that past activity of the jasmonate signal pathway in leaves may slow carbon recycling through detritivory.detritivory ͉ isopods ͉ jasmonic acid ͉ plant defense ͉ senescence H erbivory is one of the most important processes in the biosphere, whereby carbon fixed by plants is transferred to higher trophic levels (1, 2). In many cases the largest category of herbivores on the vegetative tissues of plants tends to be insects (3). Additionally, many organisms are known to prey on seeds or otherwise affect seed fate (4). However, herbivores are not the only organisms associated with plants, and only a proportion of the animals associated with plants eat living plant tissues. Another important category of organisms found associated with plants are the detritivores: feeders on dead and dying material (5). Detritivory of plant material is a second major environmental process releasing carbon from plants to higher trophic levels. Like herbivory, this is one of the truly large-scale processes in nature. Detritivores, generally considered apart from herbivores, may actively survey the plant and its vicinity looking for senescent, decaying, or otherwise compromised plant tissues. Furthermore, there is no clear division in nature between detritivory and herbivory, and many arthropods are omnivores feeding at more than one trophic level (6). It is possible that some detritivores, if given the opportunity, might be facultative herbivores. Indeed, it is conceivable that defense barriers against detritivores would be provided by the jasmonate signal pathway, because this pathway operates on the expression of hundreds of wound-inducible defense and survival genes (7) and underlies a major defense system against many herbivores (8).Through field observations we first identified arthropods potentially capable of devouring Arabidopsis seeds. These were early-stage juveniles of the nocturnal dermapteran (e...

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“…Plants treated with MeJA develop shorter petioles than do control plants (Cipollini, 2005), and the short-petiole phenotype is observed in some genetically characterized mutants that accumulate higher than wild-type levels of JA in response to wounding (Bonaventure et al, 2007). Growth inhibition mediated by JA following insult makes sense in that it allows more resource allocation for defense in plants under attack by herbivores (Zavala and Baldwin, 2006).…”

Section: Introductionmentioning

confidence: 99%

A Downstream Mediator in the Growth Repression Limb of the Jasmonate Pathway

et al. 2007

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Wounding plant tissues initiates large-scale changes in transcription coupled to growth arrest, allowing resource diversion for defense. These processes are mediated in large part by the potent lipid regulator jasmonic acid (JA). Genes selected from a list of wound-inducible transcripts regulated by the jasmonate pathway were overexpressed in Arabidopsis thaliana, and the transgenic plants were then assayed for sensitivity to methyl jasmonate (MeJA). When grown in the presence of MeJA, the roots of plants overexpressing a gene of unknown function were longer than those of wild-type plants. When transcript levels for this gene, which we named JASMONATE-ASSOCIATED1 (JAS1), were reduced by RNA interference, the plants showed increased sensitivity to MeJA and growth was inhibited. These gain-and loss-of-function assays suggest that this gene acts as a repressor of JA-inhibited growth. An alternative transcript from the gene encoding a second protein isoform with a longer C terminus failed to repress jasmonate sensitivity. This identified a conserved C-terminal sequence in JAS1 and related genes, all of which also contain Zim motifs and many of which are jasmonate-regulated. Both forms of JAS1 were found to localize to the nucleus in transient expression assays. Physiological tests of growth responses after wounding were consistent with the fact that JAS1 is a repressor of JA-regulated growth retardation.

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Jasmonic acid signalling and herbivore resistance traits constrain regrowth after herbivore attack in Nicotiana attenuata

Cited by 56 publications

References 54 publications

MYC2 Differentially Modulates Diverse Jasmonate-Dependent Functions inArabidopsis

MYC2 Differentially Modulates Diverse Jasmonate-Dependent Functions inArabidopsis

Detritivorous crustaceans become herbivores on jasmonate-deficient plants

A Downstream Mediator in the Growth Repression Limb of the Jasmonate Pathway

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