Intrinsic responses to nitrogen deficiency of Antarctic ecotypes of Colobanthus quitensis (Kunth) Bartl. and Deschampsia antarctica Desv.

IF 4.1 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Plant Science Pub Date : 2025-09-16 DOI:10.1016/j.plantsci.2025.112776

Nicolás Peña-Heyboer, Marisol Pizarro , Gustavo E. Zúñiga, Rodrigo A. Contreras

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引用次数: 0

Abstract

Antarctic vascular plants Colobanthus quitensis and Deschampsia antarctica provide unique models for studying intrinsic adaptive responses to nutrient limitation, yet their responses to nitrogen deficiency remain poorly understood. Here, we investigated their ecophysiological adjustments under controlled axenic hydroponic conditions. After 15 days of nitrogen deprivation, both species exhibited pronounced root elongation, reflecting an adaptive shift to enhance nutrient acquisition. Nitrogen stress elevated reactive oxygen species (ROS) but did not increase malondialdehyde (MDA), indicating effective activation of antioxidant defenses. Enzyme assays revealed tissue-specific and enzyme-specific regulation: nitrate reductase (NR), nitrite reductase (NiR), and glutamate synthases (Fd-GOGAT, NADH-GOGAT) were generally downregulated, while glutamate dehydrogenase isoforms (NADPH-GDH, NADH-GDH) increased, particularly in older tissues, suggesting active nitrogen remobilization. Reduced phenylalanine ammonia-lyase (PAL) activity and total phenolic content highlighted a trade-off, diverting nitrogen from secondary metabolism to sustain primary functions. Altogether, these findings provide a comprehensive view of intrinsic strategies for nitrogen stress tolerance in Antarctic plants and offer translational insights for breeding crops with improved nitrogen use efficiency and resilience to climate-induced nutrient limitations.

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南极五花子生态型对缺氮的内在响应和Deschampsia antarctica Desv。

南极维管植物Colobanthus quitensis和Deschampsia antarctica为研究它们对营养限制的内在适应性反应提供了独特的模型，但它们对氮缺乏的反应仍然知之甚少。在此，我们研究了它们在控制无菌水培条件下的生态生理调节。在缺氮15天后，两种植物的根系都出现了明显的伸长，这反映了一种增强养分获取的适应性转变。氮胁迫提高了活性氧（ROS），但没有增加丙二醛（MDA），表明抗氧化防御有效激活。酶分析显示了组织特异性和酶特异性调控：硝酸盐还原酶（NR）、亚硝酸盐还原酶（NiR）和谷氨酸合成酶（Fd-GOGAT、NADH-GOGAT）普遍下调，而谷氨酸脱氢酶（NADPH-GDH、NADH-GDH）异构体增加，特别是在老年组织中，表明活性氮再动员。苯丙氨酸解氨酶（PAL）活性和总酚含量的降低凸显了一种权衡，将氮从次级代谢转移到维持主要功能。总之，这些发现提供了对南极植物氮胁迫耐受性内在策略的全面看法，并为培育提高氮利用效率和适应气候诱导的营养限制的作物提供了转化见解。

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来源期刊

Plant Science 生物-生化与分子生物学

CiteScore

9.10

自引率

1.90%

发文量

322

审稿时长

33 days

期刊介绍： Plant Science will publish in the minimum of time, research manuscripts as well as commissioned reviews and commentaries recommended by its referees in all areas of experimental plant biology with emphasis in the broad areas of genomics, proteomics, biochemistry (including enzymology), physiology, cell biology, development, genetics, functional plant breeding, systems biology and the interaction of plants with the environment. Manuscripts for full consideration should be written concisely and essentially as a final report. The main criterion for publication is that the manuscript must contain original and significant insights that lead to a better understanding of fundamental plant biology. Papers centering on plant cell culture should be of interest to a wide audience and methods employed result in a substantial improvement over existing established techniques and approaches. Methods papers are welcome only when the technique(s) described is novel or provides a major advancement of established protocols.