Characterization of an Early Berry Development Grapevine Somatic Variant (Vitis labrusca L. cv. Isabel Precoce)

Abstract

Over the past 10 years significant advances have been made towards the description of genetics and molecular mechanisms controlling grapevine berry growth. Regardless of this, many aspects of early fruit morphogenesis and its development control remain to be elucidated. In an attempt to understand gene expression patterns associated with the berry growth development, the contrasting phenotype between the cv. Isabel (Vitis labrusca L.) and its early berry development mutant “Isabel Precoce” has been explored by a candidate gene approach. “Isabel Precoce” (Vitis labrusca L.) was confirmed as an EDV (Essentially Derived Variety) of Isabel, with a 30-35-day reduction in the berry growth phase when compared to the wild type and thus, it constitutes an informative model to investigate many aspects of fruit growth and development. Phenotypic analysis showed that “Isabel Precoce” develops fruits that are smaller in diameter and volume despite of following similar development kinetics. The expression of many genes associated with plant growth and development (MIKCC-type MADS box genes), sugar transport and with the control of flavonoid biosynthetic pathway have been evaluated. The majority of the genes presented a remarkably similar transcription profile. However, a higher induction of transcript accumulation for some genes has been observed in the “Isabel Precoce” genetic background.