Phosphite (Phi) and phosphate (Pi) share the same root uptake system, but Phi acts as a biostimulant that modulates plant growth and disease resistance in a species‑ and Pi‑dependent manner. In Arabidopsis, Phi induces hypersensitive‑like cell death and enhances resistance to Plectosphaerella cucumerina, while in rice it counteracts Pi‑induced susceptibility to Magnaporthe oryzae and Fusarium fujikuroi, accompanied by extensive transcriptional reprogramming.

The study shows that high ambient temperature triggers extensive changes in ROS homeostasis in Arabidopsis seedlings, with H2O2 balance being essential for thermomorphogenic hypocotyl elongation. PIF4 directly activates catalase genes CAT2 and CAT3 to regulate H2O2 levels, forming a PIF4‑CAT‑H2O2 module that operates alongside the PIF4‑auxin pathway, while elevated H2O2 feeds back to reduce PIF4 protein abundance.

The study examines how the SnRK1 catalytic subunit KIN10 integrates carbon availability with root growth regulation in Arabidopsis thaliana. Loss of KIN10 reduces glucose‑induced inhibition of root elongation and triggers widespread transcriptional reprogramming of metabolic and hormonal pathways, notably affecting auxin and jasmonate signaling under sucrose supplementation. These findings highlight KIN10 as a central hub linking energy status to developmental and environmental cues in roots.