Almond domestication was enabled by the selection of genotypes harboring sweet kernels, as wild almond species accumulate the bitter and toxic cyanogenic diglucoside amygdalin. We report the completion of the almond reference genome. Map-based cloning using an F1 population segregating for kernel taste led to the identification of a 46-kilobase gene cluster encoding five basic helix-loop-helix transcription factors, bHLH1 to bHLH5. Functional characterization demonstrated that bHLH2 controls the transcription of the P450 monooxygenase–encoding genes PdCYP79D16 and PdCYP71AN24, which are involved in the amygdalin biosynthetic pathway. A nonsynonymous point mutation (Leu to Phe) in the bHLH2 dimerization domain limits the expression of the two cytochrome P450 genes, resulting in the sweet kernel trait. Our results elucidate the molecular basis of one of the oldest event in the history of agriculture and lay a foundation for future advances in almond genetics and breeding.
THE GENETICS OF ALMOND DOMESTICATION
PAVAN S.;MAZZEO R.;RICCIARDI L.;
2019-01-01
Abstract
Almond domestication was enabled by the selection of genotypes harboring sweet kernels, as wild almond species accumulate the bitter and toxic cyanogenic diglucoside amygdalin. We report the completion of the almond reference genome. Map-based cloning using an F1 population segregating for kernel taste led to the identification of a 46-kilobase gene cluster encoding five basic helix-loop-helix transcription factors, bHLH1 to bHLH5. Functional characterization demonstrated that bHLH2 controls the transcription of the P450 monooxygenase–encoding genes PdCYP79D16 and PdCYP71AN24, which are involved in the amygdalin biosynthetic pathway. A nonsynonymous point mutation (Leu to Phe) in the bHLH2 dimerization domain limits the expression of the two cytochrome P450 genes, resulting in the sweet kernel trait. Our results elucidate the molecular basis of one of the oldest event in the history of agriculture and lay a foundation for future advances in almond genetics and breeding.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
