Physiological responses of two moss species to the combined stress of water deficit and elevated N deposition (II): Carbon and nitrogen metabolism.
Physiological responses of two moss species to the combined stress of water deficit and elevated N deposition (II): Carbon and nitrogen metabolism.
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两种苔藓对水分亏缺和氮沉降增加联合胁迫的生理反应（二）：碳氮代谢
DOI：
10.1002/ece3.2521
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发表时间：
2016-11
影响因子：
2.6
通讯作者：
Liu WQ
中科院分区：
文献类型：
--
作者：
Liu BY;Lei CY;Jin JH;Guan YY;Li S;Zhang YS;Liu WQ
全球极端干旱事件的氮(N)沉积水平和频率正在增加。为了更好地了解植物对相关胁迫的反应，我们调查了苔藓在高氮条件下对干旱的反应。更具体地说，我们暴露了PogonatumCirratum亚种。对不同的硝酸盐(KNO3)和氯化铵(NH4CL)处理，以及水分胁迫后即刻和短期恢复后的碳(C)、氮代谢相关指标进行了监测。结果表明，施氮促进了小麦C、N同化活性，包括核酮糖-1，5-二磷酸羧化酶、谷氨酰胺合成酶/谷氨酸合成酶(GS/GOGAT)和谷氨酸脱氢酶(GDH)活性，水分亏缺抑制了C、N同化。苔藓可以通过提高光呼吸活性和Pro含量来抵抗过量N和水分亏缺造成的胁迫。然而，供氮增加了苔藓对水分胁迫的敏感性，导致C和N同化速率急剧下降，光呼吸和Pro含量进一步增加，表明苔藓的氧化或渗透胁迫更加严重。此外，在氮素同化途径上也存在种间差异，GS/GOGAT途径和GDH途径分别是白杨和白杨在胁迫时优先利用的氨同化途径。复水后，两种苔藓对大部分C、N同化活性都表现出过度补偿效应，但施N后活性基本恢复到以前的水平(或更低)，说明施N降低了苔藓从水分亏缺胁迫中恢复的能力。总之，苔藓植物可以耐受一定程度的水分亏缺胁迫，并对环境波动具有一定的恢复能力，但氮沉积的增加降低了苔藓植物的耐受性和恢复能力。
Nitrogen (N) deposition levels and frequencies of extreme drought events are increasing globally. In efforts to improve understanding of plants' responses to associated stresses, we have investigated responses of mosses to drought under elevated nitrogen conditions. More specifically, we exposed Pogonatum cirratum subsp. fuscatum and Hypnum plumaeforme to various nitrate (KNO 3) or ammonium (NH 4Cl) treatments, with and without water deficit stress and monitored indices related to carbon (C) and N metabolism both immediately after the stress and after a short recovery period. The results show that N application stimulated both C and N assimilation activities, including ribulose‐1,5‐bisphosphate carboxylase, glutamine synthetase/glutamate synthase (GS/GOGAT), and glutamate dehydrogenase (GDH) activities, while water deficit inhibited C and N assimilation. The mosses could resist stress caused by excess N and water deficit by increasing their photorespiration activity and proline (Pro) contents. However, N supply increased their sensitivity to water stress, causing sharper reductions in C and N assimilation rates, and further increases in photorespiration and Pro contents, indicating more serious oxidative or osmotic stress in the mosses. In addition, there were interspecific differences in N assimilation pathways, as the GS/GOGAT and GDH pathways were the preferentially used ammonium assimilation pathways in P. cirratum and H. plumaeforme when stressed, respectively. After rehydration, both mosses exhibited overcompensation effects for most C and N assimilation activities, but when supplied with N, the activities were generally restored to previous levels (or less), indicating that N supply reduced their ability to recover from water deficit stress. In conclusion, mosses can tolerate a certain degree of water deficit stress and possess some resilience to environmental fluctuations, but elevated N deposition reduces their tolerance and ability to recover.
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影响因子：
7.4
作者：
GUY, CL;HUBER, JLA;HUBER, SC
通讯作者：
HUBER, SC
影响因子：
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作者：
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影响因子：
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作者：
Liu, Xuejun;Zhang, Ying;Zhang, Fusuo
通讯作者：
Zhang, Fusuo