Cioutat, a somatic variant from Chasselas exhibiting a programmed cell death-like phenotype

LIJAVETZKY, D; FERNÁNDEZ, L; DIAZ-RIQUELME, J; MARTINEZ-ZAPATER, JM

Geneva, New York, USA

Conferencia; 10th International Conference on Grapevine Breeding and Genetics; 2010

Cornell University

Somatic genetic variation constitutes an important source of phenotypic variation in grapevine. In perennial plant species where mutants are difficult to generate and screen, spontaneous somatic variants represent a unique resource to understand the genetic control of complex developmental patterns. Chasselas Cioutat is somatic variant of cultivar Chasselas displaying parsley-like leaves. Genetic analysis of a Cioutat self-cross population showed a 25% of wild-type (Chasselas) phenotype plants, consistent with the hypothesis of the phenotype being caused by a single dominant mutation. Transcriptomic comparison of Cioutat and Chasselas revealed the significant over-expression of a BAG (Bcl-2 associated athanogene) gene closely related to the Arabidopsis AtBAG6 gene in the Cioutat leaf primordia. We named that grapevine gene as VvBAG6. Interestingly, in Arabidopsis, AtBAG6 is suggested to be a stress-upregulated protein involved in programmed cell death (PCD). Moreover, a quantitative evaluation of the Cioutat phenotype in the self-cross segregant population showed a positive and statistically significant correlation between VvBAG6 expression level and the extension of the parsley leaf phenotype evaluated in the same plants. Collectively, these results suggest the involvement of PCD in the generation of the Cioutat phenotype.