The development of expansin (cell wall expansion protein)

Expansins are extracellular proteins that induce extension in isolated plant cell walls and expand on the basis of cell walls modification in vitro. It appears that they are involved in cell extension, besides cell growth, including nutrition growth, morphogenesis, pollination, fertilization and fruit softening. And they are often expressed in high specific locations and cell types. Nowdays, expansins, expansin-like sequences or their proteins were widely identified in plant and other species, the functional mechanism of them were also explored.