Plant physical defenses involve the rapid production of callose, a polysaccharide deposited between cell walls and the plasma membrane as a barrier against pathogen entry. Lignin strengthens these barriers, and callose also blocks phloem sieve plates and plasmodesmata to seal off infected cells and prevent spread.
Las defensas físicas de las plantas incluyen la producción rápida de calosa, un polisacárido depositado entre las paredes celulares y la membrana plasmática como barrera contra la entrada de patógenos. La lignina refuerza estas barreras, y la calosa también bloquea las placas de tamiz del floema y los plasmodesmos para sellar las células infectadas y prevenir la propagación.
| Front | physical defenses of plants 4.1.1(c) |
|---|---|
| Back | physical defenses - when attacked, high levels of polysaccharide callose (made of beta 1,3 and 1,6 linkages)produced between glucose - soon after attack, callose synthesised, deposited between cell walls and cell membrane in cells next to infected cells, which acts as barriers to prevent pathogens entering plant cells around site of infection - large amounts continue to be deposited, lignin added (barrier stronger now) - callose blocks sieve plates in phloem, seeling off infected part and prevent spread of pathogens - deposited in plasmodesmata between infected cells and neighbours, sealing them off for healthy cells and preventing spread |
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