Arabidopsis GH3.10 conjugates jasmonates

Jasmonates regulate plant development and defence. In angiosperms, the canonical bioactive jasmonate is jasmonoyl-isoleucine (JA-Ile), which is formed in Arabidopsis thaliana by JAR1 and GH3.10. In contrast to other jasmonate biosynthesis or perception mutants, however, gh3.10 jar1 knockout lines are still fertile. Therefore we investigated whether further jasmonates and GH3 enzymes contribute to regulation of fertility. This study found JAR1 and GH3.10 are the only contributors to JA-Ile biosynthesis in Arabidopsis and identified a number of JA conjugates as potential bioactive jasmonates acting in the absence of JA-Ile. However, their contribution in regulating fertility is yet to be conclusively determined. Transcriptomic analysis did not identify further GH3 enzymes with increased transcription rate in flowers of gh3.10 jar1 plants. RNA was prepared from flowers of Col-0 wild type and gh3.10 jar1-1, gh3.10 jar1-11 and gh3.10 jar1-12 double mutants. Flower material was harvested from flower stages 13 to 15 and pooled (Smyth et al. 1990). Samples are from one experiment with three independent biological replicates.