Crosstalk between jasmonic acid, ethylene and Nod factor signaling allows integration of diverse inputs for regulation of nodulation.
Plant hormones interact at many different levels to form a network of signaling pathways connected by antagonistic and synergistic interactions. Ethylene and jasmonic acid both act to regulate the plant's responsiveness to a common set of biotic stimuli. In addition ethylene has been shown to negatively regulate the plant's response to the rhizobial bacterial signal, Nod factor. This regulation occurs at an early step in the Nod factor signal transduction pathway, at or above Nod factor-induced calcium spiking. Here we show that jasmonic acid also inhibits the plant's responses to rhizobial bacteria, with direct effects on Nod factor-induced calcium spiking. However, unlike ethylene, jasmonic acid not only inhibits spiking but also suppresses the frequency of calcium oscillations when applied at lower concentrations. This effect of jasmonic acid is amplified in the ethylene-insensitive mutant skl, indicating an antagonistic interaction between these two hormones for regulation of Nod factor signaling. The rapidity of the effects of ethylene and jasmonic acid on Nod factor signaling suggests direct crosstalk between these three signal transduction pathways. This work provides a model by which crosstalk between signaling pathways can rapidly integrate environmental, developmental and biotic stimuli to coordinate diverse plant responses.
Sun
Jongho
J
Department of Disease and Stress Biology, John Innes Centre, Norwich NR4 7UH, UK.
Cardoza
Vinitha
V
Mitchell
David M
DM
Bright
Lydia
L
Oldroyd
Giles
G
Harris
Jeanne M
JM
D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects; D003517:Cyclopentanes / Q000494:pharmacology*; D005030:Ethylenes / Q000494:pharmacology*; D015964:Gene Expression Regulation, Bacterial; D018506:Gene Expression Regulation, Plant; D008070:Lipopolysaccharides / Q000494:pharmacology*; D046913:Medicago truncatula / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D054883:Oxylipins; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism / Q000382:microbiology; D015398:Signal Transduction / Q000187:drug effects*; D016962:Sinorhizobium meliloti / Q000378:metabolism*
D003517:Cyclopentanes; C438018:ENOD11 protein, Medicago truncatula; D005030:Ethylenes; D008070:Lipopolysaccharides; D054883:Oxylipins; D010940:Plant Proteins; C011006:jasmonic acid; C036216:ethylene; D002118:Calcium