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Module 1: Nanoparticles in Agricultural Products

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Video 1: An Overview of Seed Treatment with Iron Pyrite
So welcome back to the lecture series in nanotechnology in agriculture, so we were discussing aboutiron pyrite as the seed by stimulant.So next couple of classes we will be discussing about the mechanism of action by virtual ironpyrite helps in enhancing the production of the crops.So as of now it has been clear to most of you that iron pyrite has a complete moleculeis not entering most likely inside the seed.What is happening is that its sensitive in soluble in water, it is forming trace amountof hydrogen peroxide iron in+2 and +3 state.And SO4–ironic species, so there are cations and the anions and a peroxide kind of a milieuand all these rest of these amounts all these cationic and anionic species+the peroxideis in a trace amount.And whatever is happening it is happening because of these ironic milieus.But then in my previous class I introduce the concept of why a seed is not allowed togerminate, I told you that germination is being prevented by a series of antioxidantmolecules which are presented.And as you know in the biological system there are 3 key antioxidant molecules catalyze peroxidaseand so, peroxide dismutase.The nature has equipped as to live in an oxygen environment by virtue of these antioxidants.And here just I will take a (()) (02:25) tell you oxidant molecule can come very handy inyour immune system where you have to destroy the foreign particles or foreign cells themost of the microphagous present in our body.They eject out your free radicals in order to destroy x, y, z.But the same time these free radicals can affect your system also by destroy cells.So, it is a kind of double-digit cells.So, somewhere in between we have drawn this line of having a series of antioxidant enzymeswhich ensures there is a balance for oxidant and antioxidant kind of is being maintained.So, resuming, so there are 2 concepts what we introduce and now today we are going toput all of them together.So, just as small recap I talk to you about the chickpeas where you saw how in the waterpost treatment the growth of the chickpeas post FeS2 treatment much higher.We talked about the increase germination percentage enhance to growth enhance should growth andover all biomass increase.Then we talked about the field trials and in the field trial.I talk to you about the spinach seeds and again for 12 hours treatment in water.And correspondingly in water+iron pyrite pours that these plants were these seeds were shownmaintaining same nutrient status for the soil same amount of sun light same amount of waterno fertilizer.And equal amount of organic matter what is present in the soil.And what was observe there is an increase in the leaf size, there is an increase inthe biomass, there is increase in chlorophyll, increase in manganese, sulphur, calcium.Now where from these effects are coming, so this is where we stopped told you that a dormantseed remains dormant.Because there is a battery of antioxidant enzymes which prevents are prolongs its dormancy.So, to use the right trace here it prolongs the dormancy, now how it prolongs the dormancyand where pyrite acts onto it how it prolongs the dormancy before we get into that partthat have prolong the dormancy let us again summarize.

Video 2: Mechanistic Details of the Action of Pyrite
So, you are having pyrite, you are having trace amount of H2O2, trace amount of +, youare having SO4 to – and you are having trace amounts of H+ions and of course you are havingwater.And I told you a seed when you look at the seed, a seed in its dry dormant state hasa battery of antioxidant enzyme.And seed has huge amount of a strong result of carbohydrate and this is this carbohydratewhich decides or is the first source of energy.Now this carbohydrate when seed is germinated is the water molecules which comes and itactivates its enzymatic machinery around.And this carbohydrate is breaking down to generate energy, now what is breaking downthe carbohydrate, the enzyme which is so those of you for about carbohydrates are long chainof glucose, galactose, manose and all sorts of thing.They could be starch extremely long chain that crisscross.And there are lot of these features they collect, there are lot of these moieties forming likethis ok.And the circle is presenting each one of those glucose and moieties and x1 so far, so theseare crisscross chains like this long chains and this is what starch now these moleculesare.So, now, so this is essentially a big carbohydrate molecule, now in order to break a carbohydratemolecule what one has to do is.So, the carbohydrate each one of these individual units what you see these are monomers, thesemonomers are attached or polymerized structure through a bond called glycosidic bond whichis this one.Now in order to break carbohydrate for it to release energy what one has to do is onehas to break up this bond, if you can break up this bond then this we will release energy.And this is precisely the energy we are talking about.But breaking this bond is not an easy job, there are specific enzymes which does thatjob and one of the key class of enzyme which does that job an amylase.So, amylase activity when the seed is from its dormancy is a heading towards germinationwhat we absorbed is amylase activity goes up significantly.Because of the amylase activity going up significantly it leads to the breakdown of starch into smallmolecules like glucose.This is your glucon-D almost, so basically you want to go for 100-meter dash take a glucon-Dand you run this is precisely how a seed germinates in an environment which is extremely challengingfor it to grow that is not easy.Now these producing sugars which are getting produced they are the once which are sourceof energy.Now if you think with the way we can histone this process of make the germination to happenis somewhere other.If we could ensure the amylase activity is initiate, now what is the role of these antioxidantenzymes, so the antioxidant enzymes the prevents the amylase activity, that is what we do bystopping the amylase to act apart, what you absorb is amylase activity which is responsiblefor breaking down of the break the starch molecules are being stopped by this antioxidantenzymes.So, this is how nature maintains the balance, but the very moment water comes and startedactivating this zone the amylase gets into the plane.But now this is all fine, so for so good, then what makes the presence of pyrite sovery important, so if you look at its chlorophyll and of course the germination percentage,how pyrite is thing a role in germination now look if you look previously also the samething germination presenting.So how thus material is acting, now this is like have to give a situation I am breakinga starch you are breaking a starch.But if I break a starch faster than you then I will be more harvesting more energy fasterthan you.So, say for example you have A and you have B, so starch so our test is starch breakingspeed.So, if the starch breaking the speed of S if I represented by S.And SB is the starch breaking speed of B, if SB is more than SA than SB will germinatefaster and more successfully faster germination and more percentage germination and more successfulgermination.Now is FeS2 playing such a role, now having said this I will come back and visit thismolecule and if you look at this if you remember one old reaction called Fenton reaction wherein the presence of iron it produces hydrogen peroxide very old chemistry.I will request you to look at Fenton reaction, now if you look at the Fenton reaction andif you look on this red alphabet here or red words here something very similar to Fentonreaction production of H2O2 in the presence of iron.So, in other word FeS2 chemistry or aqueous chemistry of FeS2, so let me putit aqueous chemistry of FeS2 is similar to or reclose to Fenton reagent or Fenton chemistry.And having said this let me highlight one point here for those who are interested indegradation of organic waste which are carcinogenic which are extremely environmentally hazardous.They are places in the world where they use large amount of pyrites to execute those breakingof those huge organic molecules, how they do so now, here how they do so.You have these hydrogen peroxide here, peroxide can this is way back in 1920s is wonderfulpaper in general of biological chemistry which was published and said hydrogen peroxide canmimic mark my word carefully can mimic.The activity of amylase, so in other word FeS2 are pyrite is mimicking whole thing isFeS2+water is similar to amylase.So, in other word one can consider FeS2+water system as equivalent to amylase or artificialstarch breaking enzyme system.So, now let me get back the example what I gave you here just underlying this in pink.Now we have A and B and B has higher starch breaking speed, so automatically B will beperforming faster and will be more successful that is precise the what is happening whenFeS2 in the presence of water is generating this trace amounts of hydrogen peroxide whichis mimicking amylase activity.And going there and what it is doing is it is chopping of these glycosidic linkages andgenerating energy faster.So, it is generating more reducing sugar for more faster than naturally or in a normalprocess amylase is doing by the process.It is ensuring a faster germination and having faster germination leads to a faster growthand in that whole process the plant is getting as we will proceed further is getting a supportfrom SO42 –Fe2 Fe2+Fe3+that will be discussing subsequent classes.But there is one more thing happens this hydrogen peroxide apart from it possibly activatesa pathway which is called brassinosteroid pathway which denotes a fastergrowth and lastly H2O2 itself is a signaling metabolize for growth and development.So, hydrogen peroxide by itself does multiducting that the problem in the challenges that youcan argue that then why do not we put hydrogen peroxide directly the challenges.It acts on such a trace amount that it is not really one of the translatable technologiessecond there are certain very unique role as we will diverged it further you will absorbof these released SO42– Fe2+ Fe3+ and this milieu of slight acidic environment as wewill proceed further well describe those how they play a role.So, to conclude iron pyrite mimics in the presence of water a Fenton chemistry pointone.This is this point it while mimic Fenton chemistry generates hydrogen peroxide which mimics amylaseactivity.And just like amylase it breaks down or chop up the glycosidic linkage and thereby increasingthe possibility of the plant to absorb more or get more energy in the shortest possibletime.Because you have always had to realize when you put a seed in the soil it is facing oneof the harshest environments you can think of it.There are microbes there are completing seeds there are everything all of the place is opposingit.So, you know it has to grow faster it has to emerge out from the soil.So, in order to do that it has to really do it real quick real fast and that preciselythis process is facilitating without even getting into it and then it possibly activatesthe brassinosteroid pathways in itself with the act of the signaling molecule for developmentAnd as we will proceed further we were talked more of how FeS2 affects the root geometrywhich has a profound impact on nutrient deficient soil.And further FeS2 water system is an artificial starch breaking enzyme system, so we continuethis in our next class, thank you.