PDF(Pubmed)
Abstract：
BACKGROUND: Phosphorus (P) and iron (Fe) deficiencies are relevant plants nutritional disorders, prompting responses such as increased root exudation to aid nutrient uptake, albeit at an energy cost. Reacquiring and reusing exudates could represent an efficient energy and nitrogen saving strategy. Hence, we investigated the impact of plant development, Fe and P deficiencies on this process. Tomato seedlings were grown hydroponically for 3 weeks in Control, -Fe, and -P conditions and sampled twice a week. We used Isotope Ratio Mass-Spectrometry to measure δ13C in roots and shoots after a 2-h exposure to 13C-labeled glycine (0, 50, or 500 μmol L-1). Plant physiology was assessed with an InfraRed Gas Analyzer and ionome with an Inductively Coupled Plasma Mass-Spectrometry.
RESULTS: Glycine uptake varied with concentration, suggesting an involvement of root transporters with different substrate affinities. The uptake decreased over time, with -Fe and -P showing significantly higher values as compared to the Control. This highlights its importance during germination and in nutrient-deficient plants. Translocation to shoots declined over time in -P and Control but increased in -Fe plants, suggesting a role of Gly in the Fe xylem transport.
CONCLUSIONS: Root exudates, i.e. glycine, acquisition and their subsequent shoot translocation depend on Fe and P deficiency. The present findings highlight the importance of this adaptation to nutrient deficiencies, that can potentially enhance plants fitness. A thorough comprehension of this trait holds potential significance for selecting cultivars that can better withstand abiotic stresses.
RESULTS: Glycine uptake varied with concentration, suggesting an involvement of root transporters with different substrate affinities. The uptake decreased over time, with -Fe and -P showing significantly higher values as compared to the Control. This highlights its importance during germination and in nutrient-deficient plants. Translocation to shoots declined over time in -P and Control but increased in -Fe plants, suggesting a role of Gly in the Fe xylem transport.
CONCLUSIONS: Root exudates, i.e. glycine, acquisition and their subsequent shoot translocation depend on Fe and P deficiency. The present findings highlight the importance of this adaptation to nutrient deficiencies, that can potentially enhance plants fitness. A thorough comprehension of this trait holds potential significance for selecting cultivars that can better withstand abiotic stresses.
摘要：
背景：磷（P）和铁（Fe）缺乏是相关的植物营养障碍，促使反应，如增加根渗出，以帮助营养吸收，尽管是能源成本。重新获取和重新使用渗出物可以代表一种有效的节能和氮节省策略。因此，我们调查了植物发育的影响，此过程中的Fe和P缺陷。在对照中，番茄幼苗水培生长3周，-Fe,和-P条件，每周采样两次。在暴露于13C标记的甘氨酸（0、50或500μmolL-1）2小时后，我们使用同位素比质谱法测量了根和芽中的δ13C。使用红外气体分析仪和具有电感耦合等离子体质谱法的离子组学评估植物生理学。
结果：甘氨酸摄取随浓度而变化，表明具有不同底物亲和力的根转运蛋白的参与。摄取随着时间的推移而减少，与对照相比,-Fe和-P显示显著更高的值。这突出了其在发芽和营养缺乏的植物中的重要性。在-P和对照中，易位到芽随着时间的推移而下降，但在-Fe植物中增加，提示Gly在Fe木质部运输中的作用。
结论：根系分泌物，即甘氨酸，获取及其随后的芽易位取决于铁和磷的缺乏。目前的发现强调了这种适应营养缺乏的重要性，这可能会增强植物的适应性。对该性状的透彻理解对于选择可以更好地承受非生物胁迫的品种具有潜在意义。
结果：甘氨酸摄取随浓度而变化，表明具有不同底物亲和力的根转运蛋白的参与。摄取随着时间的推移而减少，与对照相比,-Fe和-P显示显著更高的值。这突出了其在发芽和营养缺乏的植物中的重要性。在-P和对照中，易位到芽随着时间的推移而下降，但在-Fe植物中增加，提示Gly在Fe木质部运输中的作用。
结论：根系分泌物，即甘氨酸，获取及其随后的芽易位取决于铁和磷的缺乏。目前的发现强调了这种适应营养缺乏的重要性，这可能会增强植物的适应性。对该性状的透彻理解对于选择可以更好地承受非生物胁迫的品种具有潜在意义。
