Kin Recognition in the Parasitic Plant Triphysaria versicolor Is Mediated Through Root Exudates

Abstract

Triphysaria is a facultative parasitic plant in the Orobanchaceae that parasitizes the roots of a wide range of host plants including Arabidopsis , Medicago , rice and maize. The important exception to this broad host range is that Triphysaria rarely parasitize other Triphysaria . We explored self and kin recognition in Triphysaria versicolor and showed that exudates collected from roots of host species, Arabidopsis thaliana and Medicago truncatula , induced haustorium development when applied to the roots of Triphysaria seedlings in vitro while those collected from Triphysaria did not. In mixed exudate experiments, Triphysaria exudates did not inhibit the haustorium-inducing activity of those from host roots. Interestingly, when roots of Triphysari a seedlings were treated with either horseradish peroxidase or fungal laccase, the extracts showed haustorium-inducing factor (HIF) activity, suggesting that Triphysaria roots contain the proper substrates for producing HIFs. Transgenic Triphysaria roots overexpressing a fungal laccase gene TvLCC1 showed an increased responsiveness to a known HIF, 2,6-dimethoxy benzoquinone (DMBQ), in developing haustoria. Our results indicate kin recognition in Triphysaria is associated with the lack of active HIFs in root exudates. Treatment of Triphysaria roots with enzymatic oxidases activates or releases molecules that are HIFs. This study shows that exogenously applied oxidases can activate HIFs in Triphysaria roots that had no previous HIF activity. Further studies are necessary to determine if differential oxidase activities in host and parasite roots account for the kin recognition in haustorium development.

Cytokinins Induce Prehaustoria Coordinately with Quinone Signals in the Parasitic Plant Striga hermonthica

“…DMBQ was first isolated from Sorghum extract (Chang and Lynn 1987) and is considered a major host-derived HIF. However, the amount of DMBQ in Arabidopsis root exudates is too low to account for its HIF activity (Wang et al 2020). In this study, prehaustorium induction by rice and Arabidopsis root exudates was reduced by TFBQ, ASBr and LGR-991 treatments (Fig.…”

“…Orobanchaceae parasitic plants can respond to various types of molecules as HIFs, yet the signaling pathways for each HIF and their relationships are largely unexplored. Moreover, although DMBQ was isolated from Sorghum extracts (Chang and Lynn 1986), DMBQ is barely detected in Arabidopsis thaliana root exudates, which have high prehaustorium induction activities (Wang et al 2020). Therefore, the actual molecules in host root exudates responsible for prehaustorium induction are still unknown.…”

Screening of Haustorium Induction Factors of Phelipanche aegyptiaca Pers. Based on Metabolome Analysis of Cucumis melo L. Root Exudates

“…It has been reported that the types of parasitic plant HIFs in plant root exudates mainly include phenolic acids, quinones, flavonoids, lignin units, cytokinins, and cyclohexene oxides [13], which show different haustorial induction activities for different parasitic plant species. The first HIF discovered, 2,6-dimethoxybenzoquinone (DMBQ), was isolated from sorghum roots and shown to trigger haustorium formation in Triphysaria versicolor and Striga hermonthica [16,17]. Compounds with structures similar to DMBQ, such as phenolic acids (including syringic acid, vanillic acid, and ferulic acid), aldehydes (including syringaldehyde), and flavonoids (including peonidin), have also been reported to induce haustoria in Triphyasria versicolor, Phtheirospermum japonicum, and Striga hermontica [15].…”

The effects of genetic distance, nutrient conditions, and recognition ways on outcomes of kin recognition in Glechoma longituba

“…and to receive/emit signals from the environment, and root is the major organ of below-ground performance ( Lal, 1979 ; Callaway and Mahall, 2007 ; Goebel et al, 2011 ; Depuydt, 2014 ). Root exudates are widely accepted as one of the most important mechanisms for below-ground interactions, and some previous research has focused on how root exudates mediate kin recognition ( Biedrzycki et al, 2010 ; Mercer and Eppley, 2014 ; Semchenko et al, 2015 ; Wang et al, 2020 ). Previous studies showed that root exudates mediated kin recognition in Arabidopsis thaliana ( Biedrzycki et al, 2010 ) and Distichlis spicata ( Mercer and Eppley, 2014 ).…”