RsbQ-like

Family: RsbQ-like

Block: X

Parent Family: Abhydrolase_6

Comment

The RsbQ alpha/beta hydrolase and RsbP serine phosphatase form a signaling pair required to activate the general stress factor Sigma factor sigb of Bacillus subtilis in response to energy limitation. In plants RsbQ-like proteins could function downstream of strigolactone synthesis (Strigolactones are endogenous butenolide hormones that regulate shoot and root architecture, and stimulate the branching of arbuscular mycorrhizal fungi). DWARF14(D14) act as component of hormone signaling or as enzymes that participates in the conversion of strigolactones to the bioactive form. Karrikins (KARs) represent a family of butenolide compounds found in smoke that trigger the germination of many species after fire. KAI2 (karrikin-insensitive2) is required for normal seed germination and seedling growth. Conn et al. showed that convergent evolution of strigolactone perception enabled host detection in parasitic plants. Mutations in KAI2, encoding the proposed karrikin receptor, result in hypersensitivity to water deprivation.. The parasite Striga hermonthica is causing severe yield losses of cereals in sub-Saharan Africa. The germination of Striga seeds relies on host-released strigolactones (SLs) signaling molecules. SL analogs are developped as 'suicidal germination agents'(The induction of Striga seeds germination in the absence of the host leads to the death of germinating parasite). Wang et al. show that origins of strigolactone and karrikin signaling in plants could come from horizontal transfer from bacteria. The fungi D14 Fungal-D14-Strigolactone-R although homologous to family RsbQ-like of plant strigolactone receptors are somewhat far related and cannot supplement lack of receptor in arabidopsis for example. However Bacillus subtilis RsbQ is a functional butenolide hydrolase Melville et al.