Inside of plant cell is one of the most excited frontier for scientists worldwide. I’d like to call science of tea plants as “the final frontier”.

Today I’d like to try the head trip to the world of tea plant’s cell to seek the possibilities to apply, mimic and control one of the most important organelle “tannosome”.

Tannosome is the organelle where tannins are polymerized from flavonoids such as catechin, which was recently discovered by French and Hungarian scientists [301]. Tannosome is derived from chloroplast. In chloroplast differentiation, pealing of unstacked thylakoid derive tannosome, which progressively synthesizes tannin inside.
Tannin polymerization in tannosome is assumed by the enzymes on its inside membrane. This polymerization goes on until its inside filled up by tannin.

As numerously reported, tannin exists in vacuole. Tannosome has a trip to vacuole from chloroplast with “tannsome shuttle”. Indeed, the transport of tannosome to vacuole looks like space flight by shuttle in the space of cytosol.

As mentioned previously, tea polyelectrolytes affect significantly on its taste, texture and other features. Genes relating to tannosome and factors affecting its expression, such as stresses of light, water, salt, temperature etc., would contribute strongly on characteristics of teas.

Just in my speculation, amount and activity of tannosome would have significant effect on the concentration of catechins in vacuole, affecting tea flavor. In the production of Japanese tea “Sencha”, tea leaves are rolled and pressed. At this rolling procedure, constituents including catechins in vacuole are pressed out by the pressure gained. If the amount and activity of tannosome is relatively high, the concentration of catechins is lower than the case of lower amount and activity of tannosome due to higher consumption of catechins in cytosol or vacuole. Flavor difference among tea cultivars might be related to the difference of genes corresponding to tannosome and its expression.

In the present time, there are no report for the relation between tannosome in tea plant and characteristics of teas.
It is expected to investigate characteristics of tea as functions of factors related to tannosome.

<Reference>
[301] Brillouet J.M. et al.(2013) : Annals of Botany 112:1003-1014.
==>The corresponding author, Dr. Conejero had been interviewed and its movie is uploaded.