State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (Beijing), Beijing 100083, China.
State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (Beijing), Beijing 100083, China.
Sci Total Environ. 2019 Feb 20;652:398-405. doi: 10.1016/j.scitotenv.2018.10.249. Epub 2018 Oct 19.
Coal mining results in surface subsidence and induces the development of ground fissures that damage surrounding plant roots. Very few studies have explored the stress of root damage caused by ground fissures and whether arbuscular mycorrhizal fungi (AMF) can relieve root damage stress induced by ground fissures. In the present study we simulated ground fissure induced root damage, examined the resultant changes in endogenous hormones, root system morphology, leaf area, leaf chlorophyll content, nutrient content and biomass of maize, and examined the ameliorative effects of AMF on maize with root damage. Ground fissures led to significantly higher levels of endogenous abscisic acid (ABA) but significantly reduced levels of indole-3-acetic acid (IAA), gibberellins (GA) and cytokinin (CTK). In addition, ground fissures led to significantly reduced root biomass, total root length, root tip number, total root volume, plant nutrient content, leaf chlorophyll content and leaf area. The shoot biomass of root damaged maize decreased significantly by 46%. By contrast, AMF increased IAA and CTK levels in maize roots, reduced ABA levels, improved the hormone balance of damaged plants, increased total root length, root tip number, total root volume, leaf area and leaf chlorophyll content, increased nutrient content and increased shoot biomass by 34%. Overall, by simulating coal mining subsidence ground fissures, the study investigated the effects of root damage stress on plant biomass, found that AMF can alleviate the mechanical damages to the root system, and provided a theoretical basis for microbial remediation in areas subject to subsidence due to coal mining.
采煤导致地表沉降，并引发地裂缝的发育，从而破坏周围植物的根系。很少有研究探讨地裂缝对根系造成的损伤所带来的压力，以及丛枝菌根真菌（AMF）是否可以缓解地裂缝引起的根系损伤压力。在本研究中，我们模拟了地裂缝引起的根系损伤，研究了内源激素、根系形态、叶面积、叶片叶绿素含量、养分含量和玉米生物量的变化，并研究了 AMF 对受损根系玉米的改良作用。地裂缝导致内源脱落酸（ABA）水平显著升高，但吲哚-3-乙酸（IAA）、赤霉素（GA）和细胞分裂素（CTK）水平显著降低。此外，地裂缝导致根系生物量、总根长、根尖数、总根体积、植物养分含量、叶片叶绿素含量和叶面积显著减少。受损玉米的地上生物量减少了 46%。相比之下，AMF 增加了玉米根系中的 IAA 和 CTK 水平，降低了 ABA 水平，改善了受损植物的激素平衡，增加了总根长、根尖数、总根体积、叶面积和叶片叶绿素含量，增加了养分含量，使地上生物量增加了 34%。总的来说，通过模拟采煤沉陷地裂缝，研究了根系损伤对植物生物量的影响，发现 AMF 可以缓解根系的机械损伤，并为采煤沉陷区的微生物修复提供了理论依据。
