Abstract: To understand the physiological adaptation mechanism of mycorrhizalized tobacco plants to heavy metal stress，a pot experiment which took the flue‑cured tobacco Yuyan No. 7 as marerial，was carried out to study the physiological characteristics of tobacco affected by inoculating（AM） and uninoculating（NM）arbuscular mycorrhizal fungi at different As and Cd levels（0，1，30 mg/kg），to explore the physiological mechanisms of microbial mitigation of Cd and As toxicity in flue‑cured tobacco，and provide some reference for safe production of flue‑cured tobacco.The results indicated that compared with CK（Cd=0 mg/kg and As=0 mg/kg），As stress had no effect on the infection and colonization of mycorrhizal fungi on tobacco plants，and Cd stress significantly reduced the infestation rate of arbuscular mycorrhizal fungi.With the intensification of Cd or As stress，shoot leaf area，photosynthetic parameters such as net photosynthetic rate（Pn），stomatal conductance（Gs），intercellular CO2 concentration（Ci），transpiration rate（Tr）and root morphological indexes such as total root length，root surface area and root volume of flue‑cured tobacco decreased in NM treatment，and the lowest was under 30 mg/kg stress，while the above indexes were improved by AM treatment.Inoculation with arbuscular mycorrhizal fungi could effectively promote the synthesis of glutathione（GSH），the shoot and root antioxidant of tobacco under heavy metal stress，and reduce the accumulation of Cd and As in the aerial part and roots of flue‑cured tobacco，and the Cd content of shoot and root in AM treatment under 30 mg/kg Cd stress was reduced by 40.55% and 23.19%，and the As content under 30 mg/kg As was reduced by 20.94% and 78.50%，respectively，compared with NM treatment. In a nutshell，inoculation with arbuscular mycorrhizal fungi can improve the developmental metabolism of tobacco under Cd and As stress，regulate the synthesis and secretion of GSH，and thus reduce the accumulation of Cd and As in tobacco plants.

Key words: Arbuscular mycorrhizal fungi, Flue?cured tobacco, Cadmium, Arsenic, Glutathione, Physiological characteristics

摘要： 为了解丛枝菌根化烟株对重金属胁迫的适应生理机制，采用盆栽土培试验，研究不同As、Cd水平（0、1、30 mg/kg）下接种（AM）和不接种（NM）丛枝菌根真菌对烤烟豫烟7号生理特性的影响，探讨微生物缓解烤烟Cd、As毒害的生理机制，为烤烟安全生产提供理论依据。结果表明，与CK（Cd=0 mg/kg、As=0 mg/kg）相比，As胁迫对丛枝菌根真菌侵染烟株、定殖生长均无影响，Cd胁迫均显著降低丛枝菌根真菌的侵染率。随着Cd或As胁迫程度加剧，NM处理烤烟地上部叶面积，净光合速率（Pn）、气孔导度（Gs）、胞间CO2浓度（Ci）、蒸腾速率（Tr）等光合参数以及总根长、根表面积、根体积等根系形态指标降低，在30 mg/kg胁迫水平下最低，AM处理烟株上述指标均得到不同程度提高。接种丛枝菌根真菌可有效促进重金属胁迫下烟草地上部和根系抗氧化剂谷胱甘肽（GSH）的合成、降低烤烟地上部和根系中Cd、As累积；30 mg/kg Cd 胁迫下AM 处理烟株地上部、根系Cd 含量较NM 处理分别降低40.55%、23.19%，30 mg/kg As胁迫下As含量则分别降低20.94%、78.50%。综上，接种丛枝菌根真菌可改善Cd、As胁迫下烟草的发育代谢，调节GSH的合成与分泌，从而降低烟株对Cd、As的累积。

关键词: 丛枝菌根真菌, 烤烟, 镉, 砷, 谷胱甘肽, 生理特性