Scientists Characterize CRISPR Mutants Targeting Genes Modulating Pectin Degradation in Ripening Tomato
Shelf life is one of the most important quality traits of tomato linked to
modifications in cuticle properties and remodelling of the fruit cell walls.
Previous studies have shown that a range of pectin degrading enzymes are
involved in cell wall remodelling, which mostly involved only one gene.
An international team of scientists reported in Plant Physiology the
successful generation of CRISPR-based mutants in the ripening-related genes
encoding the pectin degrading enzymes pectate lyase (PL), polygalacturonase
2a (PG2a) and â-galactanase (TBG4). When they compared the physiochemical
properties of the fruits from a range of PL, PG2a and TBG4 CRISPR lines, it
was found that only mutations in PL led in firmer fruits, although mutations
in PG2a and TBG4 affected fruit color and weight. Investigation on pectin
localization, distribution, and solubility in the pericarp cells of the
CRISPR mutant fruits showed that PL, PG2a and TBG4 act on separate cell wall
domains and the importance of cellulose microfibril-associated pectin is
reflected in its increased occurrence in the different mutant lines.