Long distance transport of mineral nutrients In higher plants an adequate transport of minerals between sites of uptake and production(sources) and site of consumption(sink) is essential The most important pathways for long distance transport are the vascular tissue(导管组织) of the xylem(木质部) and phloem(韧皮部)
Long distance transport of mineral nutrients In higher plants, an adequate transport of minerals between sites of uptake and production (sources) and site of consumption (sink) is essential. The most important pathways for long distance transport are the vascular tissue（导管组织） of the xylem（木质部） and phloem(韧皮部）
Long distance transport of mineral nutrients 木质部 xylem transport 单向运输 unitransport: water and nutrients are taken up from the root medium and translocated towards the upper plants parts by the xylem 装载 Xylem loading):K+、NO3、C等离子 为被动(ase)
• 木质部 xylem transport • 单向运输 unitransport: water and nutrients are taken up from the root medium and translocated towards the upper plants parts by the xylem • 装载(Xylem loading) ：K+ 、NO3 - 、CI -等离子 为被动(passive) Long distance transport of mineral nutrients
Long distance transport of mineral nutrients 蒸腾作用( Transpiration) The relatively high rate of water flow along the xylem vessels in an uptake direction cause a rapid translocation of solutes dissolved in the xylem vessels It is generally accepted that transpiration is the main diving force not only for water transport, but also for nutrient translocation in the xylem
• 蒸腾作用（Transpiration) • The relatively high rate of water flow along the xylem vessels in an uptake direction cause a rapid translocation of solutes dissolved in the xylem vessels. • It is generally accepted that transpiration is the main diving force not only for water transport, but also for nutrient translocation in the xylem. Long distance transport of mineral nutrients