Deposizione e citoscheletro della parete, crescita del tubetto pollinico e successo riproduttivo

The pollen tube is a tip growing cell that is crucial for reproduction of higher plants and is characterized by an intense traffic of vesicles and organelles, which in turn depends on an extended cytoskeletal apparatus consisting of actin filaments and microtubules. While the role of actin filaments is relatively known, the specific function of microtubules is uncertain, although microtubules might be involved in the localization of mitochondria and in the positioning of Golgi apparatus. By controlling the position of Golgi, microtubules might also transport the enzymes for the synthesis of callose and cellulose, which are essential for the construction of the cell wall. Being an important structure, the cytoskeleton is subject to different regulatory mechanisms, including the one related to transglutaminase activity. These enzymes are important for several cellular processes, including the response to auto-incompatibility. This association puts in relation the function of cytoskeleton and cell wall structure with the molecular mechanisms involved in the rejection of self-pollen.