Work

A Fructan 6-Exohydrolase from Orobanche cumana Boosts Waterlogging Tolerance in Parasitic and Root Tissues

Year: 2026

Type: article

Abstract: Plants adapt to abiotic stresses by a variety of physiological and molecular mechanisms, among which the root plays important roles via responding to underground and soilborne signals. Fructan is a polysaccharide that is related to energy metabolism and diverse adverse adaptations. Orobanche cumana is a holo-parasitic plant which mainly attaches to the root of host sunflower (Helianthus annuus). Here we characterized a O. cumana fructan 6-exohydrolase, Oc6-FEH, which was involved in both fructan metabolism and flooding responses. Expression of Oc6-FEH is induced by flooding and IAA treatment. Oc6-FEH possesses fructan catabolism activity and is associated with fructose release. Overexpression of Oc6-FEH in host sunflower reduces the production of MDA and H2O2, boosts the activation of antioxidant enzymes such as POD and SOD, and also elevates the photosynthetic activities. Expression level of Oc6-FEH is positively associated with flooding tolerance of invading O. cumana which is connected to host root. Furthermore, IAA treatment also improves flooding tolerance of O. cumana. In summary, the metabolism of fructan and the activity of Oc6-FEH are demonstrated to ameliorate waterlogging stress. Oc6-FEH provides a promising genetic target for improvement of flooding tolerance in crops.

Source: Plants

DOI: 10.3390/plants15091326