Early Changes in Nitrate Uptake and Assimilation Under Drought in Relation to Transpiration.
Early Changes in Nitrate Uptake and Assimilation Under Drought in Relation to Transpiration.
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干旱条件下硝酸盐吸收和同化的早期变化与蒸腾作用的关系。
DOI：
10.3389/fpls.2020.602065
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发表时间：
2020
影响因子：
5.6
通讯作者：
Geilfus CM
中科院分区：
文献类型：
--
作者：
Gloser V;Dvorackova M;Mota DH;Petrovic B;Gonzalez P;Geilfus CM
土壤干旱和氮素缺乏对农作物生产构成严重威胁。硝酸盐(NO3-−)被吸收的速率部分取决于水分的吸收和蒸腾作用。与其他氮素形态不同，硝酸盐同化的快速变化可能是植物对干旱胁迫反应的一个组成部分，因为硝酸盐同化可能导致木质部pH的变化。木质部汁液pH的调节可能与气孔调节有关，它是通过向保卫细胞输送脱落酸(ABA)来实现的。在几个析因实验中，我们研究了硝酸盐和水分有效性之间的交互作用对植物硝酸盐命运的影响，以及它们对早期干旱胁迫反应的可能影响。我们监测了豌豆、大麦、蚕豆和烟草中硝酸盐在生物量、向地上部的运输和减少中的短期反应(2-6天)，并将其与树液pH和蒸腾速率(TRs)相关联。无机基质栽培确保了对营养和水分供应的控制，并防止了豆科植物的结瘤。干旱条件下，大部分树种生物量中的NO3-−含量均下降，表明对NO3-−的吸收明显下降。即使在干旱和低NO_3-−处理下，大麦各器官中NO_3-−浓度也是最高的。该物种很可能对低N3−和缺水的综合不利影响做出更好的反应。缺水植物根和叶中硝酸还原酶活性均降低，但不缺水植物除外，这可能是由于其NO3−含量较高所致。此外，NO3-−有效性的瞬时降低对汁液pH没有影响。因此，NRA似乎不太可能从导致树干液酸碱化的茎根转移到所谓的碱化。我们也没有观察到NO3-−和水分亏缺对蒸腾作用的任何互作效应。因此，只要叶片NO_3-−含量保持稳定，土壤中NO_3-−的有效性与蒸腾作用的短期调节无关。
Soil drying combined with nitrogen (N) deficiency poses a grave threat to agricultural crop production. The rate at which nitrate (NO3−) is taken up depends partly on the uptake and transpiration of water. Rapid changes in nitrate assimilation, in contrast to other N forms, may serve as a component of the plant stress response to drought because nitrate assimilation may lead to changes in xylem pH. The modulation of xylem sap pH may be relevant for stomata regulation via the delivery of abscisic acid (ABA) to guard cells. In several factorial experiments, we investigated the interactions between nitrate and water availability on nitrate fate in the plant, as well as their possible implications for the early drought-stress response. We monitored the short-term response (2–6 days) of nitrate in biomass, transport to shoot and reduction in Pisum sativum, Hordeum vulgare, Vicia faba, and Nicotiana tabacum and correlated this with sap pH and transpiration rates (TRs). Cultivation on inorganic substrate ensured control over nutrient and water supply and prevented nodulation in legume species. NO3− content in biomass decreased in most of the species under drought indicating significant decline in NO3− uptake. Hordeum vulgare had the highest NO3− concentrations in all organs even under drought and low NO3− treatment. This species can likely respond much better to the combined adverse effects of low NO3− and water scarcity. Nitrate reductase activity (NRA) was reduced in both roots and leaves of water deficient (WD) plants in all species except H. vulgare, presumably due to its high NO3− contents. Further, transient reduction in NO3− availability had no effect on sap pH. Therefore, it seems unlikely that NRA shifts from shoot root leading to the supposed alkalization of sap. We also did not observe any interactive effects of NO3− and water deficiency on transpiration. Hence, as long as leaf NO3− content remains stable, NO3− availability in soil is not linked to short-term modulation of transpiration.
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影响因子：
6.9
作者：
Kaiser, WM;Weiner, H;Planchet, E
通讯作者：
Planchet, E
影响因子：
4.9
作者：
Buljovcic, Z;Engels, C
通讯作者：
Engels, C
影响因子：
1.9
作者：
Duan, Jianfeng;Tian, Hui;Gao, Yajun
通讯作者：
Gao, Yajun
影响因子：
5.2
作者：
Giles, Courtney D.;Brown, Lawrie K.;George, Timothy S.
通讯作者：
George, Timothy S.
影响因子：
5.3
作者：
Bassett CL;Baldo AM;Moore JT;Jenkins RM;Soffe DS;Wisniewski ME;Norelli JL;Farrell RE Jr
通讯作者：
Farrell RE Jr