Chen Sibo, Yang Siyu, Liu Wanting, Li Kaiyuan, Xue Ninghan, Ji Wenli
College of Landscape Architecture and Arts, Northwest A&F University, Xianyang 712100, China.
Plants (Basel). 2025 Aug 16;14(16):2550. doi: 10.3390/plants14162550.
Mast., a critically endangered spruce species endemic to China, is classified as a national second-level key protected wild plant and listed as critically endangered (CR) on the International Union for Conservation of Nature (IUCN) Red List. Its habitat features complex forest light environments, and global climate change coupled with environmental pollution has increased regional nitrogen deposition, posing significant challenges to its survival. This study explores the effects of light-nitrogen interactions on the leaf functional traits of Mast. seedlings by simulating combinations of light intensities (100%, 70%, and 40% full sunlight) and nitrogen application levels (0, 10, and 20 g N·m ·a, where g N·m·a denotes grams of nitrogen applied per square meter per year). We examined changes in morphological traits, anatomical structures, photosynthetic physiology, and stress resistance traits. Results indicate that moderate shading (70% full sunlight) significantly enhances leaf morphological traits (e.g., leaf length, leaf area, and specific leaf area) and anatomical features (e.g., mesophyll tissue area and resin duct cavity area), improving light capture and stress resistance. Medium- to high-nitrogen treatments (10 or 20 g N·m·a) under moderate shading further increase photosynthetic efficiency, stomatal conductance, and antioxidant enzyme activity. According to the comprehensive membership function evaluation, the L2N0 (70% full sunlight, 0 g N·m·a) treatment exhibits the most balanced performance across both growth and stress-related traits. These findings underscore the critical role of light-nitrogen interactions in the growth and adaptability of Mast. leaves, offering a scientific foundation for the conservation and ecological restoration of endangered plant populations.
秃杉是中国特有的一种极度濒危的云杉树种，被列为国家二级重点保护野生植物，在国际自然保护联盟（IUCN）红色名录中被列为极度濒危（CR）。其栖息地具有复杂的森林光照环境，全球气候变化加上环境污染导致区域氮沉降增加，对其生存构成重大挑战。本研究通过模拟光照强度（100%、70%和40%全光照）和施氮水平（0、10和20 g N·m·a，其中g N·m·a表示每平方米每年施氮克数）的组合，探讨光氮相互作用对秃杉幼苗叶片功能性状的影响。我们研究了形态性状、解剖结构、光合生理和抗逆性状的变化。结果表明，适度遮荫（70%全光照）显著增强叶片形态性状（如叶长、叶面积和比叶面积）和解剖特征（如叶肉组织面积和树脂道腔面积），提高光捕获能力和抗逆性。适度遮荫下的中高氮处理（10或20 g N·m·a）进一步提高光合效率、气孔导度和抗氧化酶活性。根据综合隶属函数评价，L2N0（70%全光照，0 g N·m·a）处理在生长和胁迫相关性状方面表现出最平衡的性能。这些发现强调了光氮相互作用在秃杉叶片生长和适应性中的关键作用，为濒危植物种群的保护和生态恢复提供了科学依据。
