In sea urchin, the acrosome reaction has 2 components:

1. Exocytosis

2. Extension of the acrosomal process

TLS Online TPP Program

#Id: 9276

#Unit 6. System Physiology – Plant

NodA is an N-acyltransferase that catalyzes the addition of a fatty acyl chain.

NodB is a chitin-oligosaccharide deacetylase that removes the acetyl group from the terminal nonreducing sugar.

NodC is a chitin-oligosaccharide synthase that links N-acetyl-D-glucosamine monomers.

TLS Online TPP Program

#Id: 9277

#Unit 6. System Physiology – Plant

Nod factor is b-1,4-linked N-acetyl-D-glucosamine backbone

TLS Online TPP Program

#Id: 9278

#Unit 6. System Physiology – Plant

Type III/Type IV secretion systems play a major role in transfer of bacterial Nod factor in plant cell. 

TLS Online TPP Program

#Id: 9279

#Unit 6. System Physiology – Plant

The binding of Nod factors to the Nod factor receptors (NFRs), which contain extracellular LysM motifs, initiates an interaction with the conserved SYMRK receptor-like kinases containing a leucine-rich repeat (LRR) domain.

TLS Online TPP Program

#Id: 9280

#Unit 6. System Physiology – Plant

The interaction between NFR and SYMRK initiates calcium spiking in the nucleus, presumably via a second messenger molecule.

Core symbiotic genes are activated.

Cytokinin signaling is initiated.

TLS Online TPP Program

#Id: 9281

#Unit 6. System Physiology – Plant

Root hair cellular responses to bacterial Nod factor