Effects of phosphorus application on photosynthetic carbon and nitrogen metabolism, water use efficiency and growth of dwarf bamboo (Fargesia rufa) subjected to water deficit
Effects of phosphorus application on photosynthetic carbon and nitrogen metabolism, water use efficiency and growth of dwarf bamboo (Fargesia rufa) subjected to water deficit
复制标题
施磷对缺水矮竹光合碳氮代谢、水分利用效率及生长的影响
DOI：
10.1016/j.plaphy.2015.07.018
复制
发表时间：
2015-11-01
影响因子：
6.5
通讯作者：
Zhang, Lin
中科院分区：
文献类型：
--
作者：
Liu, Chenggang;Wang, Yanjie;Zhang, Lin
矮竹（Fargesia rufa Yi）是濒危物种大熊猫的主食之一，由于其根部较浅，极易缺水。面对气候变化，维持和提高其生产力对大熊猫栖息地的管理是非常必要的。然而，植物对水分缺乏反应的调控机制尚不清楚。为了研究施磷对水分亏缺条件下矮竹光合碳氮代谢、水分利用效率和生长的影响，采用两种浇水（丰水和缺水）和两种施磷（施磷和不施磷）的完全随机设计。施磷对水分充足植物的生长、净CO2同化速率（P-n）和水分利用效率几乎没有影响，但显著提高了缺水植物的相对生长率（RGR）和P-n。水分胁迫下施磷对RGR的影响主要与生理调节有关，而与生物量分配差异无关。施磷维持了丰水植物碳代谢平衡，但改变了氮化合物在氮代谢中的比例。施磷显著提高了水分胁迫植株蔗糖代谢酶活性，显著降低了植株蔗糖含量，加速了植株的蔗糖代谢。施磷降低了水分胁迫植物氮素代谢酶的活性，减缓了氮素还原和铵态氮的同化。短期内施磷对矮竹响应水分的表型可塑性影响不大。一般来说，矮竹的这些性状对水磷互作的响应较弱或可以忽略。综上所述，施磷可以促进缺水矮竹的磷、糖代谢，减缓氮代谢，从而提高RGR，减轻土壤水分亏缺对矮竹的损害。(C) 2015 Elsevier Masson SAS。版权所有。
Dwarf bamboo (Fargesia rufa Yi), one of the staple foods for the endangered giant pandas, is highly susceptible to water deficit due to its shallow roots. In the face of climate change, maintenance and improvement in its productivity is very necessary for the management of the giant pandas' habitats. However, the regulatory mechanisms underlying plant responses to water deficit are poorly known. To investigate the effects of P application on photosynthetic C and N metabolism, water use efficiency (WUE) and growth of dwarf bamboo under water deficit, a completely randomized design with two factors of two watering (well-watered and water-stressed) and two P regimes (with and without P fertilization) was arranged. P application hardly changed growth, net CO2 assimilation rate (P-n) and WUE in well-watered plants but significantly increased relative growth rate (RGR) and P-n in water-stressed plants. The effect of P application on RGR under water stress was mostly associated with physiological adjustments rather than with differences in biomass allocation. P application maintained the balance of C metabolism in well-watered plants, but altered the proportion of nitrogenous compounds in N metabolism. By contrast, P application remarkably increased sucrose-metabolizing enzymes activities with an obvious decrease in sucrose content in water-stressed plants, suggesting an accelerated sucrose metabolism. Activation of nitrogen-metabolizing enzymes in water-stressed plants was attenuated after P application, thus slowing nitrate reduction and ammonium assimilation. P application hardly enlarged the phenotypic plasticity of dwarf bamboo in response to water in the short term. Generally, these examined traits of dwarf bamboo displayed weak or negligible responses to water-P interaction. In conclusion, P application could accelerate P-n and sucrose metabolism and slow N metabolism in water-stressed dwarf bamboo, and as a result improved RGR and alleviated damage from soil water deficit. (C) 2015 Elsevier Masson SAS. All rights reserved.