Engineered coumarin accumulation reduces mycotoxin‐induced oxidative stress and disease susceptibility

Abstract

SummaryCoumarins can fight pathogens and are thus promising for crop protection. Their biosynthesis, however, has not yet been engineered in crops. We tailored the constitutive accumulation of coumarins in transgenic Nicotiana benthamiana, Glycine max and Arabidopsis thaliana plants, as well as in Nicotiana tabacum BY‐2 suspension cells. We did so by overexpressing A. thaliana feruloyl‐CoA 6‐hydroxylase 1 (AtF6’H1), encoding the key enzyme of scopoletin biosynthesis. Besides scopoletin and its glucoside scopolin, esculin at low level was the only other coumarin detected in transgenic cells. Mechanical damage of scopolin‐accumulating tissue led to a swift release of scopoletin, presumably from the scopolin pool. High scopolin levels in A. thaliana roots coincided with reduced susceptibility to the root‐parasitic nematode Heterodera schachtii. In addition, transgenic soybean plants were more tolerant to the soil‐borne pathogenic fungus Fusarium virguliforme. Because mycotoxin‐induced accumulation of reactive oxygen species and cell death were reduced in the AtF6’H1‐overexpressors, the weaker sensitivity to F. virguliforme may be caused by attenuated oxidative damage of coumarin‐hyperaccumulating cells. Together, engineered coumarin accumulation is promising for enhanced disease resilience of crops.

Crop rotation alleviates continuous cropping obstacles in Chrysanthemum morifolium production by regulating rhizosphere microbial communities and metabolites

“…S2). These substances belong to the essential oil, coumarin, and alkaloid groups, and have previously been confirmed to have inhibitory effects on soil-borne pathogens (Beesley et al, 2023;Pitarokili et al, 2002;Zahari et al, 2014). The antimicrobial activities of these five pure compounds were tested and showed significant dose-dependent activity against Fusarium oxysporum mycelial growth (Fig.…”