RT Journal Article
SR Electronic
T1 Jasmonate biosynthesis arising from altered cell walls is prompted by turgor-driven mechanical compression and guides root hydrotropism
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.09.29.319012
DO 10.1101/2020.09.29.319012
A1 Stefan Mielke
A1 Marlene Zimmer
A1 Mukesh Kumar Meena
A1 René Dreos
A1 Hagen Stellmach
A1 Bettina Hause
A1 Cătălin Voiniciuc
A1 Debora Gasperini
YR 2020
UL http://biorxiv.org/content/early/2020/10/01/2020.09.29.319012.abstract
AB Despite the vital roles of jasmonoyl-isoleucine (JA-Ile) in governing plant growth and environmental acclimation, it remains unclear what intracellular processes lead to its induction. Here, we provide compelling genetic evidence that mechanical and osmotic regulation of turgor pressure represents a key factor in eliciting JA-Ile biosynthesis. After identifying cell wall mutant alleles in KORRIGAN1 (KOR1) with elevated JA-Ile in seedling roots, we found that ectopic JA-Ile resulted from cell non-autonomous signals deriving from enlarged cortex cells compressing inner tissues and stimulating JA-Ile production. Restoring cortex cell size by cell-type-specific KOR1 complementation, by isolating a genetic kor1 suppressor, and by lowering turgor pressure with hyperosmotic treatments, abolished JA-Ile signalling. Strikingly, heightened JA-Ile levels guided kor1 roots towards greater water availability, uncovering a previously unrecognized JA-Ile function in root hydrotropism. Collectively, these findings enhance our understanding of JA-Ile biosynthesis initiation, and reveal a novel role of JA-Ile in orchestrating environmental resilience.Competing Interest StatementThe authors have declared no competing interest.