COI1, a jasmonate receptor, is involved in ethylene-induced inhibition of Arabidopsis root growth in the light

Abstract

Plant response to stress is orchestrated by hormone signalling pathways including those activated by jasmonates (JAs) and by ethylene, both of which stunt root growth. COI1 is a JA receptor and is required for the known responses to this hormone. It was observed that the coi1 mutant, which is largely unresponsive to growth inhibition by JAs, was also partially unresponsive to growth inhibition by ethylene and by its immediate precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), in the light but not in the dark. Although COI1 was required for this response to ACC, other components of the JA signal perception pathway were not. Mutants selected for insensitivity to ethylene, including etr1, ein2, and ein3, showed greater ACC-induced root growth inhibition in the light than in the dark. However, the double mutants etr1;coi1, ein2;coi1, and ein3;coi1, and coi1 seedlings treated with silver ions to block the ethylene receptors showed almost complete unresponsiveness to ACC-induced root growth inhibition in the light. The light requirement for the COI1-mediated growth inhibition by ACC was for long photoperiods, and the ACC response was not abolished by mutations in the known photoreceptors. The complementation assay indicated that SCF complex assembly was not required for COI1 function in the ACC response, in contrast to the JA response. It is concluded that COI1 is required for the light-dependent, JA-independent, root growth inhibition by ethylene.

Jasmonate Controls Leaf Growth by Repressing Cell Proliferation and the Onset of Endoreduplication while Maintaining a Potential Stand-By Mode

“…The comparison of the effect of MeJA and the role of COI1 in root cells and root hair cells would suggest that COI1 has a differential role in mediating endoreduplication and/or cell expansion. This is also consistent with data showing that COI1 was required for 1-aminocyclopropane-1-carboxylic acid-induced root growth inhibition but was not required for 1-aminocyclopropane-1-carboxylic acidinduced root hair elongation (Adams et al, 2010). The quantification of nuclear surface area with H2B-YFP showed that the endocycle is initiated farther away from the QC (Fig.…”

“…MeJA inhibits the elongation of the cells in Col gl1 and aos (63% and 67%, respectively), although to a lower extent with respect to the entire root organ. In coi1-16B, the elongation of the cell was inhibited about 36%, in agreement with previous reports (Adams et al, 2010). While the root hair distribution was not obviously affected by the mutations analyzed or by MeJA treatment, the length of fully elongated root hairs in the mature region was also negatively affected by MeJA treatment (Supplemental Fig.…”

Xenobiotic- and Jasmonic Acid-Inducible Signal Transduction Pathways Have Become Interdependent at the Arabidopsis CYP81D11 Promoter

“…It was recently reported that root growth inhibition by ET was more pronounced in the two JA-Ile biosynthesis mutants dde2-2 and opr3 as compared with coi1-16 (Adams and Turner, 2010), establishing another example for a JA-Ile-independent COI1 activity.…”

Ammonium-Stimulated Root Hair Branching is Enhanced by Methyl Jasmonate and Suppressed by Ethylene in Arabidopsis thaliana

“…ORA59 is an essential integrator of the jasmonate and ethylene signal transduction pathways (Pre et al 2008). The jasmonate receptor COI1 is involved in ethylene-induced inhibition of Arabidopsis root growth in the light (Adams and Turner 2010). In contrast, ethylene inhibits the expression of some jasmonate-responsive genes encoding vegetative storage proteins (VSPs) and a thionin (Thi1.2) (Rojo et al 1999;Norman-Setterblad et al 2000;Ellis and Turner 2001), and jasmonates suppress ethylene-induced hypocotyl hook formation in the triple response in a COI1-dependent manner (Ellis and Turner 2002).…”