Chen Shuangchen, Zhao Hongjiao, Zou Chenchen, Li Yongsheng, Chen Yifei, Wang Zhonghong, Jiang Yan, Liu Airong, Zhao Puyan, Wang Mengmeng, Ahammed Golam J
College of Forestry, Henan University of Science and Technology, Luoyang, China.
Department of Plant Science, Tibet Agriculture and Animal Husbandry College, Linzhi, China.
Front Microbiol. 2017 Dec 19;8:2516. doi: 10.3389/fmicb.2017.02516. eCollection 2017.
Mycorrhizal inoculation stimulates growth, photosynthesis and nutrient uptake in a wide range of host plants. However, the ultimate effects of arbuscular mycorrhyzal (AM) symbiosis vary with the plants and fungal species involved in the association. Therefore, identification of the appropriate combinations of AM fungi (AMF) that interact synergistically to improve their benefits is of high significance. Here, three AM fungal compositions namely VT ( sp., sp., sp., sp., and sp.) and BF (, BEG and BEG 210), and (Fm) were investigated with respect to the growth, gas exchange parameters, enzymes activities in Calvin cycles and related gene expression in cucumber seedlings. The results showed that VT, BF and Fm could successfully colonize cucumber root to a different degree with the colonization rates 82.38, 74.65, and 70.32% at 46 days post inoculation, respectively. The plant height, stem diameter, dry weight, root to shoot ratio of cucumber seedlings inoculated with AMF increased significantly compared with the non-inoculated control. Moreover, AMF colonization greatly increased the root activity, chlorophyll content, net photosynthetic rate, light saturated rate of the CO assimilation (sat), maximum carboxylation rate () and maximum ribulose-1,5-bis-phosphate (RuBP) regeneration rate (max), which were increased by 52.81, 30.75, 58.76, 47.00, 69.15, and 65.53% when inoculated with VT, respectively. The activities of some key enzymes such RuBP carboxylase/oxygenase (RuBisCO), D-fructose-1,6-bisphosphatase (FBPase), D-fructose-6-phosphatase (F6P) and ribulose-5-phosphate kinase (Ru5PK), and related gene expression involved in the Calvin cycle including , , , , and were upregulated by AMF colonization. AMF inoculation also improved macro- and micro nutrient contents such as N, P, K, S, Ca, Cu, Fe, Mn, Mg, and Zn in roots. Further analysis revealed that inoculation with VT had relatively better effect on growth of cucumber seedling followed by BF and Fm, indicating that AMF composition consisting of distant AMF species may have a better effect than a single or closely related AMF spp. This study advances the understanding of plant responses to different AM fungi toward development of strategies on AMF-promoted vegetable production.
菌根接种可刺激多种寄主植物的生长、光合作用和养分吸收。然而，丛枝菌根（AM）共生的最终效果因参与共生的植物和真菌种类而异。因此，鉴定能够协同相互作用以提高其益处的合适AM真菌（AMF）组合具有重要意义。在此，研究了三种AM真菌组合，即VT（ 种、 种、 种、 种和 种）、BF（ 、BEG 和BEG 210）以及Fm，考察了它们对黄瓜幼苗生长、气体交换参数、卡尔文循环中的酶活性以及相关基因表达的影响。结果表明，VT、BF和Fm能够成功地在不同程度上定殖于黄瓜根系，接种后46天的定殖率分别为82.38%、74.65%和70.32%。接种AMF的黄瓜幼苗的株高、茎粗、干重、根冠比均显著高于未接种的对照。此外，AMF定殖显著提高了根系活力、叶绿素含量、净光合速率、CO2同化光饱和速率（Isat）、最大羧化速率（Vcmax）和最大核酮糖-1,5-二磷酸（RuBP）再生速率（Jmax），接种VT时分别提高了52.81%、30.75%、58.76%、47.00%、69.15%和65.53%。一些关键酶如RuBP羧化酶/加氧酶（RuBisCO）、D-果糖-1,6-二磷酸酶（FBPase）、D-果糖-6-磷酸酶（F6P）和核酮糖-5-磷酸激酶（Ru5PK）的活性，以及卡尔文循环中涉及的相关基因表达包括 、 、 、 、 和 均因AMF定殖而上调。接种AMF还提高了根系中大量和微量养分的含量，如N、P、K、S、Ca、Cu、Fe、Mn、Mg和Zn。进一步分析表明，接种VT对黄瓜幼苗生长的影响相对较好，其次是BF和Fm，这表明由亲缘关系较远的AMF物种组成的AMF组合可能比单一或亲缘关系较近的AMF物种具有更好的效果。本研究增进了对植物对不同AM真菌反应的理解，有助于制定促进AMF蔬菜生产的策略。
