VIP: Fruit Ripening

During fruit development,

the:eggzygotecentral cellintegumentovuleovary wall
Zygote Embryo Endosperm Seed Coat Seed Fruit


The hormone Ethylene initiates the ripening response in fruit tissue:
Unripe FruitEnzyme
Ripe Fruit
physical conditionchemical causechemical causephysical condition
green chlorophyll hydrolase anthocyanin red
hard pectin pectinase less pectin soft
sour acid kinase neutral neutral
mealy starch α-amylase sugar sweet+juicy
odorless large organics hydrolases small organics fragrance


The process above, occurring in a layer in a pedicel, causes fruit abscision.
The process above, occurring in a leaf blade, causes leaf senescence.
The process above, occurring in a layer in a petiole, causes leaf abscission.


The three fundamentally-different parts of a seed are:
seed coat storage tissue embryo


These functions:occur in these parts of the embryo:
growth of the shoot shoot apex
photosynthesis (and storage) cotyledon
lifting the shoot above the soil hypocotyl
producing lateral roots radicle
penetrating the soil root apex

This page © Ross E. Koning 1994.

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