Dipartimento di Scienze Agrarie e Ambientali, University of Udine, I-33100 Udine, Italy.
J Sci Food Agric. 2011 Jan 30;91(2):344-54. doi: 10.1002/jsfa.4192.
Unbalanced nutrient availability causes disequilibrated plant growth, which can result in a worsening of harvested product quality, such as high nitrate content in edible tissues. To cope with this problem, improved knowledge of the mechanisms involved in nutrient acquisition and regulation is necessary. For this purpose the responses of acquisition mechanisms of N, Fe and S were studied as a function of Fe and S availability using two corn salad cultivars grown hydroponically, considering also aspects related to N metabolism.
The results showed that an increase in Fe or S availability enhanced nitrate uptake and assimilation, which in turn increased biomass production of leaves with lower nitrate content. In particular, high S availability exerted a positive effect (gene expression and functionality) both on the uptake and metabolism of N and on Fe acquisition mechanisms.
The data presented here show close interactions between N, S and Fe, highlighting that relevant improvements in yield and quality from soilless culture might also be obtained through appropriate adjustments of nutrient availability. In this respect, concerning the role of S in the acquisition mechanisms of N and Fe and in N metabolism, its level of availability should be taken into high consideration for equilibrated plant growth.
养分供应不平衡会导致植物生长失衡，从而导致收获产品质量下降，例如食用组织中硝酸盐含量过高。为了解决这个问题，需要更好地了解养分吸收和调节的机制。为此，本研究以水培玉米沙拉两种品种为材料，研究了氮、铁和硫吸收机制对铁和硫供应的响应，同时还考虑了与氮代谢相关的方面。
结果表明，铁或硫供应的增加会促进硝酸盐的吸收和同化，从而增加叶片的生物量产量，同时降低硝酸盐含量。特别是，高硫供应对氮和铁吸收机制的吸收和代谢都有积极的影响（基因表达和功能）。
本文的研究结果表明氮、硫和铁之间存在密切的相互作用，突出了通过适当调整养分供应，从无土栽培中获得产量和品质的显著提高。在这方面，考虑到硫在氮和铁的吸收机制以及氮代谢中的作用，应该高度重视其可用性水平，以实现植物的均衡生长。
