Stomatal control and water transport in the xylem

摘要: [Extract] The movement of plants from aquatic to terrestrial habitats in the Ordovician placed new and conflicting demands on structure function photosynthetic organs. Protection against desiccation led formation an epidermis with low permeability water, while requirement facilitate entry gaseous CO2 close tissue favored increase epidermal porosity. This dilemma was solved early during evolution land advent stomata, which, through their ability regulate porosity, provided a means by which optimize tradeoff between carbon gain water loss. However, without reliable supply sites photosynthesis, stomata remain closed cells starve. Since evolution, xylem have been inextricably connected transpiration pathway. For given environment leaf biochemistry, rates uptake transpirational loss are controlled stomatal conductance. Thus, for same environment, higher result rates, investment represents major part cost maintaining flux keeping hydrated. chapter examines coordination focusing how these water-conducting tissues has linkage living ostensibly nonliving tissue.