Büntgen Ulf, Jandova Veronika, Dolezal Jiri
Department of Geography, University of Cambridge, Cambridge, UK.
Global Change Research Institute (CzechGlobe), Czech Academy of Sciences, Brno, Czech Republic.
Plant Cell Environ. 2025 Feb;48(2):1445-1451. doi: 10.1111/pce.15221. Epub 2024 Oct 24.
As an evolutionary achievement of almost all terrestrial plants, lignin biosynthesis is essential for various mechanical and physiological processes. Possible effects of plant cell wall lignification on large-scale vegetation distribution are, however, not yet fully understood. Here, we present double-stained, wood anatomical stem measurements of 207 perennial herbs (Potentilla pamirica Wolf), which were collected between 5550 and 5850 m asl on the north-western Tibetan Plateau in Ladakh, India. We also measured changes in situ root zone and surface air temperatures along the sampling gradient and applied piecewise structural equation models to assess direct and indirect relationships between the age and size of plants, the degree of cell wall lignification in their stems, and the elevation at which they were growing. Based on the world's highest-occurring vascular plants, the Pamir Cinquefoils, we demonstrate that the amount of lignin in the secondary cell walls decreases significantly with increasing elevation (r = -0.73; p < 0.01). Since elevation is a proxy for temperature, our findings suggest a thermal constrain on lignin biosynthesis at the cold range limit of woody plant growth.
作为几乎所有陆生植物的一项进化成果，木质素生物合成对于各种机械和生理过程至关重要。然而，植物细胞壁木质化对大规模植被分布的可能影响尚未完全了解。在此，我们展示了对207种多年生草本植物（帕米尔委陵菜）进行的双重染色、木材解剖学茎干测量，这些植物是在印度拉达克的青藏高原西北部海拔5550至5850米处采集的。我们还沿着采样梯度测量了原位根区和地表气温的变化，并应用分段结构方程模型来评估植物的年龄和大小、茎中细胞壁木质化程度以及它们生长的海拔之间的直接和间接关系。基于世界上海拔分布最高的维管植物——帕米尔委陵菜，我们证明次生细胞壁中木质素的含量随着海拔升高而显著降低（r = -0.73；p < 0.01）。由于海拔是温度的一个指标，我们的研究结果表明在木本植物生长的寒冷范围极限处，木质素生物合成受到热限制。
