Tang Shuanglei, Lin Xiazhen, Li Wen, Guo Chengjin, Han Jungang, Yu Lei
Department of Ecology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China.
Teaching Center, Zhejiang Open University, Hangzhou, China.
Physiol Plant. 2023 Jul-Aug;175(4):e13980. doi: 10.1111/ppl.13980.
Nutrient resorption can increase nutrient use and play important roles in terrestrial plant nutrient cycles. Although several studies have reported individual responses of plant nutrient resorption to drought or shade stress, the interaction of drought and shade remains unclear, especially for dioecious plants. This study explored whether nutrient resorption is correlated to growth characteristics (such as biomass and root/shoot ratio [R/S ratio]) and leaf economics (such as leaf thickness, leaf mass per area [LMA] and leaf vein density [LVD]) in female and male Populus cathayana across different conditions. We found that drought stress significantly increased nitrogen (N) resorption efficiency (NRE) in both sexes, but shade and interactive stress decreased NRE in P. cathayana females. Under drought stress, nutrient resorption was sexually dimorphic such that P. cathayana males have higher NRE than females. Furthermore, NRE and phosphorous (P) resorption efficiency (PRE) were positively related to R/S ratio, leaf thickness, LMA, and LVD in both sexes across different treatments. Our study is the first to present how nutrient resorption is related to biomass accumulation and allocation, and leaf economics, suggesting that nutrient uptake may be modulated by R/S ratio and leaf economics, which is important for understanding the conservation mechanism of plant nutrients.
养分重吸收可以提高养分利用效率，并在陆地植物养分循环中发挥重要作用。尽管有几项研究报告了植物养分重吸收对干旱或遮荫胁迫的个体响应，但干旱和遮荫的相互作用仍不清楚，尤其是对于雌雄异株植物。本研究探讨了在不同条件下，毛果杨雌雄株的养分重吸收是否与生长特征（如生物量和根冠比[R/S比]）以及叶片经济学特征（如叶片厚度、单位面积叶质量[LMA]和叶脉密度[LVD]）相关。我们发现，干旱胁迫显著提高了雌雄株的氮（N）重吸收效率（NRE），但遮荫和交互胁迫降低了毛果杨雌株的NRE。在干旱胁迫下，养分重吸收存在性别差异，毛果杨雄株的NRE高于雌株。此外，在不同处理下，雌雄株的NRE和磷（P）重吸收效率（PRE）均与R/S比、叶片厚度、LMA和LVD呈正相关。我们的研究首次揭示了养分重吸收与生物量积累和分配以及叶片经济学特征之间的关系，表明养分吸收可能受R/S比和叶片经济学特征的调节，这对于理解植物养分的保存机制具有重要意义。
