植物生态学报 ›› 2016, Vol. 40 ›› Issue (1): 60-68.DOI: 10.17521/cjpe.2015.0273

• 研究论文 • 上一篇    下一篇

CO2浓度倍增对红松幼苗根尖和叶解剖结构及生理功能的影响

王娜, 张韫, 钱文丽, 王政权, 谷加存*()   

  1. 东北林业大学林学院, 哈尔滨 150040
  • 出版日期:2016-01-01 发布日期:2016-01-28
  • 通讯作者: 谷加存
  • 作者简介:# 共同第一作者
  • 基金资助:

    中央高校基本科研业务费专项资金项目(2572015AA21)和国家自然科学基金(31100470)。

Effects of elevated CO2 concentration on root and needle anatomy and physiological functions in Pinus koraiensis seedlings

WANG Na, ZHANG Yun, QIAN Wen-Li, WANG Zheng-Quan, GU Jia-Cun*   

  1. School of Forestry, Northeast Forestry University, Harbin 150040, China
  • Online:2016-01-01 Published:2016-01-28
  • Contact: Jia-Cun GU
  • About author:# Co-first authors

摘要:

大气CO2浓度升高对植物的影响是目前植物生态学研究中普遍关注的问题。以往的研究主要关注植物地上部分叶解剖结构及生理功能的改变, 而对根解剖结构和生理功能变化以及根与叶变化之间潜在联系的研究较少。该文以三年生红松(Pinus koraiensis)幼苗为研究对象, 通过CO2浓度倍增(从350 µmol·mol-1增加到700 µmol·mol-1)试验, 研究当年生针叶和根尖解剖结构及生理功能的变化。结果表明: (1) CO2浓度倍增处理的红松幼苗, 气孔密度显著降低, 叶肉组织面积、木质部及韧皮部面积明显增加; (2) CO2浓度倍增导致红松幼苗根尖直径增粗, 皮层厚度和层数显著增加, 管胞直径变小; (3)高CO2浓度处理下, 叶气孔导度和蒸腾速率降低, 光合速率和水分利用效率提高, 同时根尖的导水率显著下降, 但管胞的抗栓塞能力显著提高。这些结果显示, 叶和根解剖结构及生理功能在CO2浓度升高条件下具有一致的响应。未来研究中应该同时关注全球气候变化对植物地上和地下器官结构与功能的影响。

关键词: 解剖结构, 大气CO2浓度, 叶, 根, 全球变化

Abstract: AimsThe impacts of CO2 concentration on the anatomy and physiology of plant roots have rarely been studied. Here we studied the effects of elevated CO2 on anatomical and physiological traits of needles and root tips in Pinus koraiensis seedlings. Our objectives were: 1) to examine how the anatomy of needles and root tips change under doubled CO2 concentration treatment; and 2) to explore physiological responses of needles and root tips to the rising CO2 concentration; and 3) to reveal potential relationships of physiological trait changes between needles and root tips.MethodsThree-year-old seedlings of P. koraiensis were grown in CO2 chambers under doubled and ambient CO2 concentrations (350 and 700 µmol·mol-1). Physiological traits of needles were measured by the LI-6400 portable photosynthesis system during the experiment. After 5 months, needles and root tips were sampled to determine their anatomical characteristics. Theoretical hydraulic conductivity of needles and root tips were calculated based on the Hagen-Poiseuille’s Law.Important findings Elevated CO2 concentration had a significant influence on the anatomical characteristics of needles and root tips in P. koraiensis seedlings. Under doubled CO2 concentration, needles had a lower stomatal desnity, greater areas of leaf mesophyll, phloem and xylem. In comparision, root tips under doubled CO2 concentration had a larger diameter, a greater cortical thickness and a larger number of cortical cell layer. Physiological traits of needles and root tips also changed substantially under the elevated CO2 concentration, such as increases in needle photosynthetic rate and water use efficiency, xylem cavitation resistance of roots, as well as decreases in stomatal conductance, transpiration rate and root hydraulic conductivity. These results suggest that the anatomical structure and physiological function of leaf and root respond simultaneously to elevated CO2 concentration. Future studies should not only focus on the impact of global climate change on aboveground organs and fuctions, but also to the belowground counterparts.

Key words: anatomical structure, atmospheric CO2 concentration, needles, roots, global change