Raquel Sánchez Pérez
"Ramón y Cajal" fellow
Campus Universitario de Espinardo, 30100 Murcia, Spain
Telf.: +34 968396200, ext. 6116
The majority of the temperate fruit tree species belongs to the Rosaceae family, which encompasses about 100 different genera with more than 2000 species. Within this family, Prunus is one of the most important genera from an agronomical point of view producing more than 40 MMt worldwide of peaches and nectarines, apricots, almonds and sweet and sour cherries, cultivated in 1.7 MM ha.
Climate change is forcing not only fruit tree breeders to improve their efforts in developing new varieties that can be adapted and be economically competent in the new climate conditions, but also scientists to develop new and natural treatments that can compensate for the loss of chilling units that plants need to make an effective and yearly even fruit production.
It is known how important is the application of MAS in breeding programs as i.e. almond. In general, the global objective of a Prunus breeding program is obtaining new cultivars, self-compatible, of extra-late or extra-early blooming, productive, of high-quality fruit / kernels (i.e. sweet, firmness, low acidity etc.) with a chemical composition resulting in an excellent quality from the points of view sensorial, commercial, industrial and healthy. The knowledge of easy and suitable biotechnological tools is crucial for the development of molecular markers.
My research topic is the study of important agronomic traits within Prunus species to develop molecular markers to help breeders and growers in a climate change context. The main disadvantage of these species is their long juvenile period of three to four years, as occurs in almond, apricot, or even more in cherry etc.. These species only bloom once a year. Therefore, we have to wait two to three years to have statistical results when experiments are performed in reproductive organs such as flowers and fruits.
Due to these factors, the time necessary to obtain a new Prunus variety, e.g. almond, is approximately 10 years.
On the other hand, these plant species contain cyanogenic glucosides as prunasin and amygdalin that when cells are disrupted results in the release of hydrogen cyanide. We have recently elucidated the gene responsible for bitterness in almond by the sequencing of the almond genome, together with biochemistry and physiological studies. These results have been published in the prestigious scientific journal Science.
Mutation of a bHLH transcription factor allowed almond domestication
Publication date: 14-06-2019
Authors: Sánchez-Pérez R*, Pavan S, Mazzeo R, Moldovan C, Aiese R, Del Cueto J, Ricciardi F, Lotti C, Ricciardi L, Dicenta F, López-Marqués R, Møller BL
Wild almond species accumulate the bitter and toxic cyanogenic diglucoside amygdalin. Almond domestication was enabled by the selection of genotypes harboring sweet kernels. 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 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 dimerization domain of bHLH2 prevents transcription of the two cytochrome P450 genes, resulting in the sweet kernel trait.
|LAST PRESS RELEASES|
21-06-2019 | Weekendavisen.dk
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