After cleavage by caspase-3, truncated XKR8, together with either basigin (BSG) or neuroplastin (NPTN), undergoes dimerization and activation and translocates

phospholipids in both directions.

TLS Online TPP Program

#Id: 7101

#Unit 6. System Physiology – Plant

TLS Online TPP Program

#Id: 7102

#Unit 6. System Physiology – Plant

Aminoethoxy-vinylglycine (AVG) and aminooxyacetic acid (AOA) block the conversion of AdoMet to ACC.

AVG and AOA are known to inhibit enzymes that use the cofactor pyridoxal phosphate. The cobalt ion (Co2+) is also an inhibitor of the ethylene biosynthetic pathway, blocking the conversion of ACC to ethylene by ACC oxidase, the last step in ethylene biosynthesis

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#Id: 7103

#Unit 6. System Physiology – Plant

ETO1 is a component of a ubiquitin-ligase complex

ETO1 targets ACS proteins for  ubiquitination and proteolysis by the 26S proteosome.

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#Unit 6. System Physiology – Plant

Wounding and pathogen attack phosphorylate ACS so that ETO1 can not ubiquitinylate ACS hence stabilized

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#Unit 6. System Physiology – Plant

Inhibitors of ethylene synthesis

IN CASE OF TOMATOES:

pTOM5 encodes for phytoene synthase which promote  lycopene synthesis that gives red coloration

pTOM6 gene encodes for polygalacturonase. This enzyme  degrades the cell wall, resulting in fruit softening.

pTOM gene encodes for ACC oxidase. This enzyme  catalyzes the ethylene formation that triggers the fruit ripening.

Calgene introduced a gene in plant which synthesize a  complementary mRNA to PG gene and inhibiting the  synthesis of PG enzyme.

On May 21, 1994, the genetically engineered Flavr Savr tomato was introduced.

TLS Online TPP Program

#Id: 7106

#Unit 6. System Physiology – Plant

Inhibitors of ethylene action

Most of the effects of ethylene can be antagonized by specific ethylene inhibitors. Silver ions (Ag+) applied as silver nitrate (AgNO3) or as silver thiosulfate (Ag(S2O3)2 3–) are potent inhibitors of ethylene action. Silver is very specific; the inhibition it causes cannot be induced by any other metal ion.