title: The plant vascular system: evolution, development and functions.
abstract: The emergence of the tracheophyte-based vascular system of land plants had major impacts on the evolution of terrestrial biology, in general, through its role in facilitating the development of plants with increased stature, photosynthetic output, and ability to colonize a greatly expanded range of environmental habitats. Recently, considerable progress has been made in terms of our understanding of the developmental and physiological programs involved in the formation and function of the plant vascular system. In this review, we first examine the evolutionary events that gave rise to the tracheophytes, followed by analysis of the genetic and hormonal networks that cooperate to orchestrate vascular development in the gymnosperms and angiosperms. The two essential functions performed by the vascular system, namely the delivery of resources (water, essential mineral nutrients, sugars and amino acids) to the various plant organs and provision of mechanical support are next discussed. Here, we focus on critical questions relating to structural and physiological properties controlling the delivery of material through the xylem and phloem. Recent discoveries into the role of the vascular system as an effective long-distance communication system are next assessed in terms of the coordination of developmental, physiological and defense-related processes, at the whole-plant level. A concerted effort has been made to integrate all these new findings into a comprehensive picture of the state-of-the-art in the area of plant vascular biology. Finally, areas important for future research are highlighted in terms of their likely contribution both to basic knowledge and applications to primary industry.
authors: Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA. wjlucas@ucdavis.edu
authors: William J
authors: WJ
authors: Lucas
authors: Andrew
authors: A
authors: Groover
authors: Raffael
authors: R
authors: Lichtenberger
authors: Kaori
authors: K
authors: Furuta
authors: Shri-Ram
authors: SR
authors: Yadav
authors: Ykä
authors: Y
authors: Helariutta
authors: Xin-Qiang
authors: XQ
authors: He
authors: Hiroo
authors: H
authors: Fukuda
authors: Julie
authors: J
authors: Kang
authors: Siobhan M
authors: SM
authors: Brady
authors: John W
authors: JW
authors: Patrick
authors: John
authors: J
authors: Sperry
authors: Akiko
authors: A
authors: Yoshida
authors: Ana-Flor
authors: AF
authors: López-Millán
authors: Michael A
authors: MA
authors: Grusak
authors: Pradeep
authors: P
authors: Kachroo
mesh_terms: D005075:Biological Evolution; D052585:Phloem / Q000033:anatomy & histology / Q000378:metabolism / Q000502:physiology; D010944:Plants / Q000033:anatomy & histology / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D052584:Xylem / Q000033:anatomy & histology / Q000378:metabolism / Q000502:physiology