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 s...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 essentialfunctions 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.展开更多
Seed vigor refers to the overall capacity of the seed to （1） germi- nate and emerge after sowing （i.e., germination vigor） and （2） retain this potential during postharvest storage, known as seed longevity. Seed ...Seed vigor refers to the overall capacity of the seed to （1） germi- nate and emerge after sowing （i.e., germination vigor） and （2） retain this potential during postharvest storage, known as seed longevity. Seed vigor plays vital roles in plant growth and realiza- tion of crop productivity. Long shelf life of seeds and their rapid and uniform germination and seedling emergence are highly desirable commercial traits. Despite its central importance, how seeds acquire their vigor is poorly understood.展开更多
基金supported in part by the National Science Foundation (grants IOS-0752997 and IOS-0918433 to WJL grants IOS#0749731, IOS#051909 to PK)+8 种基金the Department of Energy, Division of Energy Biosciences (grantsDE-FG02-94ER20134 to WJL)the US Department of Agriculture, Agricultural Research Service (under Agreement number58-6250-0-008 to MAG)the Spanish Ministry of Science andInnovation (MICINN) (grants AGL2007-61948 and AGL2009-09018 to AFLM)the Ministry of Education, Science, Sportsand Culture of Japan (grant 19060009 to HF)the JapanSociety for the Promotion of Science (JSPS grant 23227001to HF)the NC-CARP project (to HF)the NationalKey Basic Research Program of China (grant 2012CB114500to XH)the National Natural Science Foundation of China (grant31070156 to XH)the NSFC-JSPS cooperation project(grant 31011140070 to HF and XH)
文摘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 essentialfunctions 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.
文摘Seed vigor refers to the overall capacity of the seed to （1） germi- nate and emerge after sowing （i.e., germination vigor） and （2） retain this potential during postharvest storage, known as seed longevity. Seed vigor plays vital roles in plant growth and realiza- tion of crop productivity. Long shelf life of seeds and their rapid and uniform germination and seedling emergence are highly desirable commercial traits. Despite its central importance, how seeds acquire their vigor is poorly understood.
