Expression of phenylalanine ammonia lyase during ripening of different strawberry cultivars.

POMBO MA; MARTÍNEZ GA; CIVELLO PM

Villa Carlos Paz, Pcia. Córdoba,

Congreso; XLIV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2008

SAIB

Ripening fruit undergo a complex developmental process that involves changes in the morphology and metabolism of their tissues. In some cases, one of the most important trait that make fruit attractive to the consumers, are the accumulation of anthocyanin pigments. In Strawberry fruit (Fragaria x ananassa, Duch), development of fruit colour is associated to the phenylpropanoid pathway. Phenylalanine ammonia lyase (PAL) is a key enzyme in this pathway, determining Strawberry fruit quality. In this work, we analysed the levels of anthocyanins during fruit ripening of cultivars with different colour development (Camarosa, intense red colour, and Toyonaka, light red). Toyonaka showed a lower accumulation of anthocyanins compared to Camarosa. In addition, we have designed specific primers to generate a 249 bp FaPAL gene fragment, which was used as a probe for expression analysis. FaPAL expression was detected in all stages analysed except in white stage in both cultivars, but the mRNA levels were higher in Camarosa. Finally, both cultivars showed similar rates of increment in PAL activity at the beginning of ripening. However, at the end of ripening PAL activity diminished in Toyonaka, while it rose markedly in Camarosa. Therefore, the higher FaPAL expression and PAL activity detected in Camarosa could be associated to the enhanced anthocyanin accumulation found in this cultivar.