Models of Vascular Pattern Formation in Leaves.

摘要: The vegetative hormone Auxin is involved in vascular tissues formation throughout the plant. Trans-membrane carrier proteins transporting auxin from cell to and distributed asymmetrically around each give a polarized movement tissues, creating streams of that presume future bundles. According canalization hypothesis, transport ability cells thought increase with flux, resulting self-enhancement this flux along paths. In study we evaluate series models based on hypothesis using proteins, under different assumptions concerning protein dynamics. Simulations are run hexagonal lattice uniform production. A single located margin indicates petiole, acts as an sink. main results are: (1) We obtain branching distribution patterns. (2) type described by functional form regulation responding intensity parts cell, has strong effect possibility generating For response functions acceleration numbers compared patterns likely be generated. linear or decelerating functions, no formed. (3) When formed, greatly differs between case which number regulated independently, compete for limited proteins. former case, level lower veins than surrounding tissue, while latter, present greater abundance veins. These suggest good candidate describing plant vein pattern formation. ****** Formation system leaves can explained states formed initially homogeneous field self-organizing process Previous generate but fail closed loops. However, loops commonly observed important making them robust herbivore attacks physical damage. Here propose new model generates postulate ‘‘flux bifurcator'' enhanced high it causes reallocation carriers toward neighbouring also having bifurcator level. This bifurcate, allowing tips attach other explore several alternative forms affecting efflux examine parameter dependence pattern.