Solute fluxes from tobacco to the parasitic angiosperm Orobanche cernua and the influence of infection on host carbon and nitrogen relations
Solute fluxes from tobacco to the parasitic angiosperm Orobanche cernua and the influence of infection on host carbon and nitrogen relations
复制标题
从烟草到寄生被子植物列当的溶质通量以及感染对宿主碳氮关系的影响
DOI：
--
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
W. D. Jeschke
中科院分区：
文献类型：
--
作者：
J. Hibberd;W. P. Quick;M. Press;J. Scholes;W. D. Jeschke
列当属物种是全寄生虫，其是宿主衍生的溶质的非常有效的汇。在这里，我们报告使用的木质部汁液溶质浓度和水通量的直接测量，连同建模过程来计算元素通量内的关联列当cernua和它的烟草宿主之间。烟草的寄生虫感染显着影响碳的收购和分配，净固定碳比对照组高20%。列当使烟草地上部向下的净碳通量增加了84%，其中73%的碳被寄生虫拦截，几乎完全通过韧皮部（>99%）。此外，寄生虫还对植物的氮素关系产生了很大的影响，特别是刺激了硝酸盐的吸收，木质部汁液的氨基酸含量较低。该寄生虫还严重依赖寄主韧皮部提供其他资源，只有5 - 15%的N，16%的K，23%的Na，63%的Mg和13%的S来自木质部。因此，我们提供了定量信息的韧皮部依赖的寄生虫，并表明，主机的碳和氮代谢刺激作为感染的结果。
Orobanche species are holoparasites which are very efficient sinks for host-derived solutes. Here, we report the use of direct measurements of xylem sap solute concentrations and water fluxes, together with a modelling procedure to calculate element fluxes within an association between Orobanche cernua and its tobacco host. Infection of tobacco by the parasite markedly influenced carbon acquisition and partitioning; net fixation of carbon was 20% higher in infected tobacco compared with controls. Orobanche cernua caused a 84% increase in net carbon flux moving downward from the tobacco shoot and 73% of this carbon was intercepted by the parasite, almost entirely through the phloem (>99%). Further, the parasite also exerted a large impact on the nitrogen relations of the plant, notably nitrate uptake was stimulated and the amino acid content of xylem sap was lower. The parasite also relied heavily on host phloem for the supply of other resources, with only 5 to 15% of N, and 16% of K, 23% of Na, 63% of Mg and 13% of S being derived from the xylem. Thus, we provide quantitative information on the phloem dependency of the parasite and show that host carbon and nitrogen metabolism is stimulated as a consequence of infection.