Department of Plant Biology and Ecology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, E-01006, Vitoria-Gasteiz, Spain; Phytophthora Research Centre, Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic.
Department of Plant Biology and Ecology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, E-01006, Vitoria-Gasteiz, Spain.
Plant Sci. 2020 Apr;293:110418. doi: 10.1016/j.plantsci.2020.110418. Epub 2020 Jan 22.
Nitrogen is one of the main factors that affect plant growth and development. However, high nitrogen concentrations can inhibit both shoot and root growth, even though the processes involved in this inhibition are still unknown. The aim of this work was to identify the metabolic alterations that induce the inhibition of root growth caused by high nitrate supply, when the whole plant growth is also reduced. High nitrate altered nitrogen and carbon metabolism, reducing the content of sugars and inducing the accumulation of Ca and amino acids, such as glutamate, alanine and γ-aminobutyrate (GABA), that could act to replenish the succinate pool in the tricarboxylic acid cycle and maintain its activity. Other metabolic alterations found were the accumulation of the polyamines spermidine and spermine, and the reduction of jasmonic acid (JA) and the ethylene precursor aminocyclopropane-1-carboxylic acid (ACC). These results indicate that the growth root inhibition by high NO is a complex metabolic response that involves GABA as a key link between C and N metabolism which, together with plant growth regulators such as auxins, cytokinins, abscisic acid, JA, and the ethylene precursor ACC, is able to regulate the metabolic response of root grown under high nitrate concentrations.
氮是影响植物生长和发育的主要因素之一。然而，高浓度的氮会抑制地上部和根部的生长，尽管这种抑制的过程尚不清楚。本研究的目的是确定在整个植物生长受到抑制的情况下，高硝酸盐供应引起根生长抑制的代谢变化。高硝酸盐改变了氮碳代谢，降低了糖的含量，并诱导钙和氨基酸（如谷氨酸、丙氨酸和γ-氨基丁酸（GABA））的积累，这些物质可以补充三羧酸循环中的琥珀酸池并维持其活性。还发现了其他代谢变化，包括多胺亚精胺和精胺的积累，以及茉莉酸（JA）和乙烯前体 1-氨基环丙烷-1-羧酸（ACC）的减少。这些结果表明，高 NO 引起的根生长抑制是一种复杂的代谢反应，其中 GABA 作为 C 和 N 代谢之间的关键联系，与植物生长调节剂如生长素、细胞分裂素、脱落酸、JA 和乙烯前体 ACC 一起，能够调节在高硝酸盐浓度下生长的根的代谢反应。
