Cellular and Tissue Localization of Tarpot Indole Alkaloids Biosynthesis

[Music] [Music] welcome to pharmacognosy and metabolic

engineering one of the nptl online certification course uh so we we will go to lecture number 29 so where I am going

to show today about the cell and tissue localization of tarpo indol alkaloids so I will do some drawing in the board and

the enthusiastic students may also draw along with me in the board so that their concept will get

clear let's go to the board so what I'm going to cover here is the compartment ation of tarpo indal

alkaloid pathway in catharanthus Rosas okay

so what we have seen that uh the different entic states are operating

with in the cell so let us make a heading for this Cellular location uh cellular

localization of both

enzymes and and intermediates

during tarpo indol

alkaloid biosynthesis this is a

cell okay and I will put

the vual here maybe a slightly and this is

the chloroplast we'll start with

uh see in the chloro in the chloroplast map pathway is

operating uh which color I is that leads to the formation of

geranial and this janal will be transported out

and moves into the vacle whereas the another source of geranial

will be from the cytool where M

pathway may also contribute to the formation of geranial so this genal will be converted

into CH hydroxy genal by the enzyme

sorry uh Geral 10 hydroxy which I will put in brown color and eventually from this

gerenal seanin will be synthesized

and where okay triamine is also present and this

leads to the formation of strict

toyin tryptamine comes from tryptophan so this

tryptophan may also come from uh plased localized secate

pathway so here what I'll do I'll do slight changes in the drawing so this is

uh cryopen and this geranial is coming from

MEP that is also operated inside the plastid I think now it is clear to all of you and this troid in one it

is produced inside the vacol this will go out into the

cytool so how it is passing through the cytosol is again an interesting

question are there any transporter responsible for that so this I will answer in one of the subsequent classes

so I'll not talk about this today so this troiden will be now

out and it will be subsequently converted into stto in a

glycon by the action of SGD so SGD we must look at is

GD okay so the arrow to be made further okay and then this leads to the

formation of 421 gasio IID in so I will not the full

form here because of the shortage of space g so and then from there one root goes

towards tonin and other root

[Music] produces C

this Cen thing will again enter into the

vual and this will be the tonin this tonin

now moves into the through cytool and moves through the

cytool into the chloroplast so if I put the arrow right so

here you have the endoplasmic reticulum ER where

the t16 H is localized so the pathway

moves from ton and then from here it moves through

cytool and then it enters into the

chloroplast and and then a reaction catalyzed by

this will be an empty and then the next

step uh D atile vindoline will be

there oh so the arrow has to be the color of the arrow has to be changed

sorry this is taking time but uh if you draw with me

then you can visualize the pathway

and then it makes windol in and this

vindoline again enters into the vacle so cathan enters vindoline

enters and these uh

for lolin this joins together by a peroxides and form

the M blasting well so the enzyme responsible for this

is peroxidase and here lies the D the d4h is

here okay and uh another

root from the this also makes the camine and

that makes aalin and asalin

enters into the vle and converted into

serpentin so now let us Define this is basically the

chloroplast this is the cytoplasm this is the endoplasmic

reticulum and uh this one is the

vacu so this is in brief the cellular localization of both enzymes and

intermediates during tpid indol alkaloid biosynthesis so once this is clear now we

will see another Drive uh

to from the anatomy point of view let's go to the next slide so

here basically I will write putative trafficking

of pathway intermediates and

products in in monotaro in

alkaloid metabolism so here I draw a structure

uh transverse section of the leaf see on the top of it it is a cuticle layer and then next to the cuticle is

basically the epidermis to epidermis consist

of epidermal cells then you have the palisad

parena and then one of this you will have the valy

set video blast and uh next you have

this and also you have another specialized

okay then I think I will use uh this color this

better we have spongy cells for

so these are the vascular tissue

so these are ipap ipap stands

for internal flu

Associated parena okay so this

is sorry well now let me Define palis d blast this is the

Val said idioblast

and this is the spongy

mop video blast uh this is

called laifer okay now let us see what is there so first of all this is

cuticle so this is the epidermis so now here will'll see the

pathway the cryptophanes cryptomine

joins with seanin

makes stripto in up to from there

so we write 16 methoxy

taronin then this moves so this is Mia

intermediates this further moves down to here this also goes down

to here so this is palis idioblast where dtile

Molin converted to vindoline by the this one similarly here

also same thing happens the the atile

vindoline converted into vindoline and

here the M path originates it

makes geranial and that

subsequently moves and uh this also moves

to here also where the aile vindoline converted into

vindoline okay so this is

pised palena so what we see that in the leaf structure normally

Leaf contains the paliside and spongy Paden Kima but here what you see that there

are uh specialized structures formed one is called

laisar another is called idioblast so these latis and eblast the

are these are specialized cells so this contains

latex and why it contains latex because the late steps of diary indol alcol or okay the monotor

inter alals are toxic to the cell itself therefore de atile vindoline vindoline and maybe the subsequent Vin Christin

and hydro Vin blastin these are toxic to the cells so uh plant has developed specialized cells to

accommodate these toxic metabolites and these specialized cells are laifer and idioblast which contains latex and these

metabolites these monomeric and dieric indol alkaloids are stored in the latex so that it is safe for the plant species

as well so that is why this is so both in the paliside as well as the spongy parena the ID blast are there so this is

in brief the uh this is basically a transverse faction of the LI so I if I if you ask me to put a caption for this

so This figure is basically the uh transverse

section of a catharanthus Rus Leaf

portion so this is in brief the uh the anatomical structure of the leaf tissue and where the pathway

operates but still uh it's not uh complete uh because I just okay I'll make uh before I end this class I'll

make a short list here so this laifer and the ID blast as I said so

here this portion d4h D these enzymes are

localized whereas in the leaf epidermis all other enzymes are localized such

as TDC s Str

SGD t6h M2 not only even T3

oxidase T3 reductase and nmt so the epidermal tissues are

very active tissue for the uh indol alol biosynthesis now I may end the class

here but in the next class I'll show you another pictorial diagram where uh I will

show that again this structure but there what I will put I will put the mopile tissue FL parena

idioblast laifer uh and epidermal cell along with the extracellular space extracellular

and the cell surface because what we will what I will tell that uh some of this final monomeric IND alkaloids are

secreted out to the leaf surface that is again a new discovery and that plays important role in

defending the leps from predators so I will not name the alcal today okay so let us keep it for the

next class so with this I end this class