PubMed · 2026-07-08
Scientists discovered that a molecular 'off switch' on a key protein pump in Arabidopsis plants controls how well the plant defends itself against insect attack. By fine-tuning this pump's activity, plants coordinate electrical alarm signals, hormone responses, and defensive chemistry across their entire body.
Removing the autoinhibitory C-tail of the AHA1 proton pump increased pump activity and shortened the electrical repolarization signal after wounding, reducing expression of the jasmonate defense marker JAZ10 in both wounded and distant leaves.
Phloem sieve tube elements are specifically required for transmitting electrical defense signals systemically, confirmed by selectively boosting AHA1 activity only in those cells.
Glucosinolate levels were strongly elevated in aha1-7 loss-of-function mutants but not in C-tail truncation lines, linking pump regulation to a distinct branch of sulfur-based insect defense chemistry.
