Pyroptosis A form of regulated programmed cell death associated with inflammation, and often associated with infection with intracellular pathogens. Mediated by inflammasome-activated caspase-1.

TLS Online TPP Program

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#Unit 6. System Physiology – Plant

The response to ethylene is very rapid and causes triple response which is

Reduced elongation

Hypocotyl swelling

Apical hook exaggeration

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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#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

TLS Online TPP Program

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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.