The origin and evolution of vascular tissue regulators in plants
Plants and trees have tremendous influence on planet Earth, its atmosphere and the many organisms that live on our planet. But how did plants manage to be rigid and grow tall enough to affect our planet so drastically? One of the key factors that creates such mechanical strength are vascular tissues: a transportation system for water and nutrients that simultaneously provides support. We tried to uncover which genes were involved in the development of this important tissue, by studying the genome of different plant species (species with and without vascular tissue). We identified two genes that code for co-operative proteins: TARGET OF MONOPTEROS 5 (TMO5) and LONESOME HIGHWAY (LHW). The complex that they form together can induce cell divisions, creating larger and stronger vascular bundles. Changes in the structure and function of this complex appears to have played an important role in the development of thick and rigid vascular tissues and may thus have allowed plants to grow beyond the size of mosses and affect the world like it did.