Root exudates of wheat are involved in suppression of Fusarium wilt in watermelon in watermelon-wheat companion cropping

Companion cropping with wheat increases resistance to Fusarium wilt in watermelon and the roles of root exudates in watermelon root growth

“…Hao et al [19] demonstrated the mechanism in which rice root exudates inhibited spore germination and sporulation of Fon in a watermelon/aerobic rice intercropping system. In previous study, we found that there was no significant difference in mycelium growth of Fon with or without the D 125 wheat root exudates [48]. However, this experiment showed that watermelon seedlings could resist against Fusarium wilt in the companion cropping with D 125 wheat system as compared to monoculture (Fig.…”

“…In previous studies, we found that companion cropping with D 125 , a different wheat cultivar, could improve the watermelon growth [49,50]. However, D 125 wheat root exudates could not inhibit mycelial growth of Fon [48]. So far, no reports have confirmed whether companion cropping with wheat can reduce the occurrence of Fusarium wilt in watermelon through improving watermelon growth.…”

“…Plant species or genotypes managed potential benefit to soil-borne diseases through root exudates [18]. Xu et al [48] reported that companion cropping with D 123 wheat could alleviate Fusarium wilt in watermelon through inhibiting the mycelia growth of Fon. In previous studies, we found that companion cropping with D 125 , a different wheat cultivar, could improve the watermelon growth [49,50].…”

The genetics underlying natural variation of plant–plant interactions, a beloved but forgotten member of the family of biotic interactions

“…Interestingly, exudates from maize were shown to contain salicylic acid, a potent inducer of SAR, which could also explain the induction of PR genes in soybean roots. Similar results were obtained in watermelon roots when grown together with wheat: PAL activity was higher in watermelon leaves and the induction of several defense‐related genes was enhanced upon infection by pathogenic fungus Fusarium oxysporum (Xu et al ., ). In a couple of studies, exudates or purified molecules from root exudates produced by one plant species were shown to alter the expression of immunity markers in different plant species.…”

“…niveum ∞ 2 several defense-related activities reduced (before infection) Ren et al , 2008 Soybean/Maize Cylindrocladium parasiticum 1.7 PR , PAL and PPO gene induction enhanced (after infection) Gao et al , 2014 Watermelon/Wheat Fusarium oxysporum f. sp. niveum 3.9 Induction of AOS , PAL and other genes enhanced (after infection but not before) Xu et al , 2015 Tomato/Onion mesh or barrier separating the root systems from the two species showed that this induction of defense-related genes likely requires the diffusion of molecular signals from maize to soybean. Interestingly, exudates from maize were shown to contain salicylic acid, a potent inducer of SAR, which could also explain the induction of PR genes in soybean roots.…”