CePP2C19 confers tolerance to drought by regulating the ABA sensitivity in Cyperus esculentus.

Background: Tiger nut (Cyperus esculentus) is widely known as an additional source of food, oil and feed worldwide. The agricultural production of tiger nut has been greatly hindered by drought stress, reducing both yield and quality. Protein phosphatase 2 C (PP2Cs) plays an important role in plant responses to drought stress however, the molecular mechanism of PP2Cs in tiger nuts still unclear. Results: In this study, we identified a putative group A PP2C-encoding gene (CePP2C19) from tiger nut using transcriptome analysis, which is highly induced by drought stress. The transient expression assay suggested that CePP2C19 was localized to nucleus. Furthermore, the interaction between CePP2C19 and CePYR1, a coreceptor for ABA signaling, was first detected using a yeast two-hybrid assay and then verified using a bimolecular fluorescence complementation (BiFC) analysis. In addition, the transgenic Arabidopsis lines overexpressing CePP2C19 exhibited extreme tolerance to ABA and mannitol stresses during seed germination and root growth. At the mature stage, overexpression of CePP2C19 resulted in a higher tolerance to drought stress in transgenic Arabidopsis, as confirmed by a visible phenotype and several physiological parameters. Noticeably, the silencing of CePP2C19 by virus-induced gene silencing (VIGS) showed obvious reduction in drought tolerance in tiger nut plants. Conclusions: The CePP2C19 emerges as a pivotal gene involved in the ABA signaling pathway, which likely reduce ABA sensitivity and thus enhances drought tolerance in Cyperus esculentus. [ABSTRACT FROM AUTHOR]