Symbiosis with Penicillium sp. D7 rewires molecular modules to boost plant growth and As(III) stress tolerance.

Penicillium sp. D7 enhances Arabidopsis thaliana growth under arsenic (As(III)) stress by five-fold through reprogramming hormone signaling and detoxification pathways.

• Why it matters: Arsenic contamination hampers plant growth and agricultural productivity, especially in mining-affected soils, and microbial symbionts like D7 may offer sustainable solutions for phytoremediation.
• What they did: Researchers isolated Penicillium sp. D7 from As-rich tailings, co-cultivated it with Arabidopsis, and performed transcriptome profiling, along with functional analyses using mutant lines to understand its effects on hormone signaling and detoxification.
• The result: D7 significantly boosts plant growth, suppresses root ABA stress pathways, induces shoot auxin biosynthesis, and enhances vacuolar sequestration of As(III), suggesting it improves detoxification capacity without reducing As uptake.