MMP2 is a protein that digests extracellular matrices (such as the zona) and may be responsible for digesting a pathway to the oocyte Acrosin bind secondarily to the zona, keeping the sperm in the channel it creates

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

TLS Online TPP Program

#Id: 9282

#Unit 6. System Physiology – Plant

Plant genes expressed early, or in the absence of bacterial infection, are termed “early nodulins” or ENOD

TLS Online TPP Program

#Id: 9283

#Unit 6. System Physiology – Plant

Three factors are important in maintaining low O2 concentrations in nodules. 

First, entry of O2 into the nodule is controlled by a variable‐permeability barrier in the nodule parenchyma