Biochemical and molecular aspects of fruitlet abscission

Citation
C. Bonghi et al., Biochemical and molecular aspects of fruitlet abscission, PLANT GR R, 31(1-2), 2000, pp. 35-42
Citations number
42
Categorie Soggetti
Plant Sciences
Journal title
PLANT GROWTH REGULATION
ISSN journal
01676903 → ACNP
Volume
31
Issue
1-2
Year of publication
2000
Pages
35 - 42
Database
ISI
SICI code
0167-6903(200005)31:1-2<35:BAMAOF>2.0.ZU;2-G
Abstract
Fruitlet abscission during fruit development is due to the activation of pr e-differentiated abscission zones (AZs) located between twig and pedicel, a nd/or pedicel and pericarp. Major advances on biochemical and molecular asp ects are related to beta-1,4-endoglucanase (EG) and polygalacturonase (PG), two cell hydrolases involved in the cell wall disassemblement responsible for fruit shedding. AZ activation is accompanied by an increase in activity and transcript accumulation of one or both enzymes. Expression of PG genes specifically related to abscission has been found in tomato flower AZ. In peach, an EG gene highly expressed in leaf and fruitlet AZs has been isolat ed. AZ activation is preceded by an induction of ethylene biosynthesis, par alleled by a stimulation of ACO activity and transcript accumulation. Ethyl ene, besides a dramatic stimulation of PG and EG, up or down regulates seve ral other abscission related genes. The specific expression of genes encodi ng for ethylene receptors in the AZ would support the hypothesis that fruit let AZ specificity may depend on the ability of this region to sense ethyle ne.