Lin Jixiang, Peng Xiaoyuan, Hua Xiaoyu, Sun Shengnan, Wang Yingnan, Yan Xiufeng
Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Key Laboratory of Saline-alkali Vegetation Ecology Restoration in Oil Field, Ministry of Education Harbin 150040 China
Department of Plant Pathology, North Carolina State University Raleigh NC 27695-7716 USA.
RSC Adv. 2018 Apr 18;8(26):14500-14509. doi: 10.1039/c8ra00721g. eCollection 2018 Apr 17.
Nitrogen deposition and soil salinization-alkalization have become major environmental problems throughout the world. is the dominant, and considered the most valuable, species for grassland restoration in the Northeast of China. However, little information exists concerning the role of arbuscular mycorrhizal fungi (AMF) in the adaptation of seedlings to the interactive effects of nitrogen and salt-alkali stress, especially from the perspective of osmotic adjustment and ion balance. Experiments were conducted in a greenhouse and seedlings were cultivated with NaCl/NaHCO under two nitrogen treatments (different concentrations of NH /NO ). Root colonization, seedling growth, ion content, and solute accumulation were measured. The results showed that the colonization rate and the dry weights of the seedlings were both decreased with the increasing salt-alkali concentration, and were much lower under alkali stress. Both of the nitrogen treatments decreased the colonization rate and dry weights compared with those of the AM seedlings, especially under the N2 (more NH -N content) treatment. The Na content increased but the K content decreased under salt-alkali stress, and more markedly under alkali stress. AMF colonization decreased the Na content and increased the K content to some extent. In addition, the nitrogen treatments had a negative effect on the two ions in the AM seedlings. Under salt stress, the seedlings accumulated abundant Cl to maintain osmotic and ionic balance, but alkali stress inhibited the absorption of anions and the seedlings accumulated organic acids in order to resist the imbalance of both osmosis and ions, whether under the AM or nitrogen treatments. In addition, proline accumulation is thought to be a typical adaptive feature in both AM and non-AM plants under nitrogen and salt-alkali stress. Our results suggest that the salt-alkali tolerance of seedlings is enhanced by association with arbuscular mycorrhizal fungi, and the seedlings can adapt to the nitrogen and salt-alkali conditions by adjusting their osmotic adjustment and ion balance. Excessive nitrogen partly decreased the salt-alkali tolerance of the seedlings
氮沉降和土壤盐碱化已成为全球主要的环境问题。[物种名称]是中国东北草原恢复的优势种，也是最具价值的物种。然而，关于丛枝菌根真菌（AMF）在幼苗适应氮和盐碱胁迫交互作用中的作用，尤其是从渗透调节和离子平衡角度的相关信息较少。在温室中进行实验，在两种氮处理（不同浓度的NH₄⁺/NO₃⁻）下用NaCl/NaHCO₃培养[物种名称]幼苗。测定了根系定殖、幼苗生长、离子含量和溶质积累情况。结果表明，随着盐碱浓度的增加，定殖率和幼苗干重均降低，且在碱胁迫下更低。与AM幼苗相比，两种氮处理均降低了定殖率和干重，尤其是在N₂（NH₄⁺-N含量更高）处理下。盐碱胁迫下Na含量增加而K含量降低，在碱胁迫下更明显。AMF定殖在一定程度上降低了Na含量并增加了K含量。此外，氮处理对AM幼苗中的这两种离子有负面影响。在盐胁迫下，幼苗积累大量Cl⁻以维持渗透和离子平衡，但碱胁迫抑制了阴离子的吸收，幼苗积累有机酸以抵抗渗透和离子的失衡，无论是在AM还是氮处理下。此外，脯氨酸积累被认为是AM和非AM植物在氮和盐碱胁迫下的典型适应性特征。我们的结果表明，[物种名称]幼苗与丛枝菌根真菌共生可增强其耐盐碱能力，幼苗可通过调节渗透调节和离子平衡来适应氮和盐碱条件。过量的氮部分降低了[物种名称]幼苗的耐盐碱能力
