Early humic acid-induced eustress triggers biostimulant responses in Arabidopsis thaliana: RBOHC-derived H2O2 drives growth promotion while RBOHD enables nutritional reprogramming.
Root-applied humic acids (HAs) promote plant development, yet the early signaling mechanisms underlying their biostimulant action remain incompletely understood. Here, we show that treatment of Arabidopsis thaliana roots with a sedimentary humic acid (SHA) triggers a transient eustress-like response, characterized by e...