Functional Analysis of LAZY1 in Arabidopsis thaliana and Prunus Trees

摘要

Technology to optimize plant architecture is critical for future efforts to increase planting density in a wide range of crops. Little is known regarding the molecular mechanisms governing this basic plant developmental feature, particularly in fruit trees. Recently, a pair of distantly related genes called LAZY1 and TILLER ANGLE CONTROL 1 (TAC1) was shown to have opposing effects on lateral branch angle in monocots and dicots. We have characterized the LAZY1 gene in both Arabidopsis and plum (Prunus domestica) and assessed its functional relationship with TAC1. Both lazy1 and tac1:lazy1 Arabidopsis plants showed a previously unreported weeping phenotype. Transgenic plum lines silenced for LAZY1 showed horizontal branch angles, sometimes marked by rootward lateral branch growth. Our results establish that manipulation of LAZY1 gene function results in changes in tree shape and can be used to engineer fruit or ornamental trees with desired branch angles.