Experimental study reveals differential herbicide tolerance and a three-phase detoxification network in hemp, highlighting molecular targets for weed management.
Key Points
To evaluate the phenotypic tolerance of hemp (Cannabis sativa L.) across eight post-emergence herbicides and determine the molecular mechanisms underlying tolerance to bispyribac-sodium.
Screened hemp plants in greenhouse conditions against eight post-emergence herbicides to measure phytotoxicity and mortality rates.
Determined herbicide sensitivity by calculating the GR50 for bispyribac-sodium.
Conducted RNA sequencing at 24 and 48 hours post-treatment with bispyribac-sodium and performed weighted gene co-expression network analysis (WGCNA) to profile transcriptional responses.
ACCase inhibitors caused minimal phytotoxicity, whereas atrazine, metribuzin, metsulfuron-methyl, and oxyfluorfen led to complete plant mortality.
Bispyribac-sodium induced partial tolerance, yielding a GR50 of 21.55 g a.i. ha−1.
Identified a core suite of 21 consistently upregulated detoxification genes, including tau-class GSTs, UGTs, CYP families (CYP71, CYP72, CYP81, CYP716), and an ABCB transporter, spanning early MAPK signaling and phase I–III detoxification to late endoplasmic reticulum stress.