Editing Tannin (section)

===Cellular localization===
{{more references |section |date=September 2021}}
In all vascular plants studied, tannins are manufactured by a [[chloroplast]]-derived [[organelle]], the [[tannosome]].<ref>{{cite journal |doi=10.1093/aob/mct168 |volume=112 |title=The tannosome is an organelle forming condensed tannins in the chlorophyllous organs of Tracheophyta |year=2013 |journal=Annals of Botany |pages=1003–1014 |last1=Brillouet |first1=J.-M. |issue=6 |pmid=24026439 |pmc=3783233}}</ref> Tannins are mainly physically located in the [[vacuole]]s or surface wax of plants. These storage sites keep tannins active against plant predators, but also keep some tannins from affecting plant metabolism while the plant tissue is alive.

Tannins are classified as [[ergastic substance]]s, i.e., non-protoplasm materials found in cells. Tannins, by definition, precipitate proteins. In this condition, they must be stored in organelles able to withstand the protein precipitation process. [[Idioblast]]s are isolated plant cells which differ from neighboring tissues and contain non-living substances. They have various functions such as storage of reserves, excretory materials, pigments, and minerals. They could contain oil, latex, gum, resin or pigments etc. They also can contain tannins. In Japanese persimmon (''[[Diospyros kaki]]'') fruits, tannin is accumulated in the vacuole of tannin cells, which are idioblasts of parenchyma cells in the flesh.<ref>{{cite journal |last1=Kanzaki |first1=Shinya |last2=Yonemori |first2=Keizo |last3=Sugiura |first3=Akira |last4=Sato |first4=Akihiko |last5=Yamada |first5=Masahiko |year=2001  |title=Identification of Molecular Markers Linked to the Trait of Natural Astringency Loss of Japanese Persimmon (''Diospyros kaki'') Fruit |journal=Journal of the American Society for Horticultural Science |volume=126 |issue=1 |pages=51–55 |doi=10.21273/JASHS.126.1.51 |url=http://journal.ashspublications.org/content/126/1/51.full.pdf+html |archive-url=https://web.archive.org/web/20150904065618/http://journal.ashspublications.org/content/126/1/51.full.pdf+html |archive-date=4 September 2015|doi-access=free }})</ref>