Amiguet-Vercher, AmeliaSantuari, LucaGonzález Guzmán, MiguelDepuydt, StephenRodríguez Egea, Pedro LuísHardtke, Christian S.2017-06-062017-06-062015-020028-646Xhttps://riunet.upv.es/handle/10251/82420[EN] Natural genetic variation is crucial for adaptability of plants to different environments. Seed dormancy prevents precocious germination in unsuitable conditions and is an adaptation to a major macro-environmental parameter, the seasonal variation in temperature and day length. Here we report the isolation of IBO, a quantitative trait locus (QTL) that governs c. 30% of germination rate variance in an Arabidopsis recombinant inbred line (RIL) population derived from the parental accessions Eilenburg-0 (Eil-0) and Loch Ness-0 (Lc-0).IBO encodes an uncharacterized phosphatase 2C-related protein, but neither the Eil-0 nor the Lc-0 variant, which differ in a single amino acid, have any appreciable phosphatase activity in in vitro assays. However, we found that the amino acid change in the Lc-0 variant of the IBO protein confers reduced germination rate. Moreover, unlike the Eil-0 variant of the protein, the Lc-0 variant can interfere with the activity of the phosphatase 2C ABSCISIC ACID INSENSITIVE 1 in vitro. This suggests that the Lc-0 variant possibly interferes with abscisic acid signaling, a notion that is supported by physiological assays. Thus, we isolated an example of a QTL allele with a nonsynonymous amino acid change that might mediate local adaptation of seed germination timing.Reserva de todos los derechosAbscisic acid (ABA)Arabidopsis thalianaIBONatural variationPhosphatase 2C (PP2C)Quantitative trait locus (QTL)MICROBIOLOGIABIOQUIMICA Y BIOLOGIA MOLECULARArtículo10.1111/nph.13225Cerrado1469-813725490966