The photoprotective role of arbuscular mycorrhizal fungi (AMF) in cucumber seedlings under cold stress

2018 ◽  
pp. 305-318
Author(s):  
Jun Ma ◽  
M. Janoušková ◽  
Yan Yan ◽  
Xianchang Yu ◽  
Zhirong Zou ◽  
...  
2015 ◽  
Vol 42 (12) ◽  
pp. 1158 ◽  
Author(s):  
Jun Ma ◽  
Martina Janoušková ◽  
Yansu Li ◽  
Xianchang Yu ◽  
Yan Yan ◽  
...  

Symbiosis with root-associated arbuscular mycorrhizal fungi (AMF) can improve plant phosphorus (P) uptake and alleviate environmental stresses. It could be also an effective mean to promote plant performance under low temperatures. The combined effects of arbuscular mycorrhiza and low temperature (15°C/10°C day/night) on cucumber seedlings were investigated in the present study. Root colonisation by AMF, succinate dehydrogenase and alkaline phosphatase activity in the intraradical fungal structures, plant growth parameters, and expression profiles of four cucumber phosphate (Pi) transporters, the fungal Pi transporter GintPT and alkaline phosphatase GintALP were determined. Cold stress reduced plant growth and mycorrhizal colonisation. Inoculation improved cucumber growth under ambient temperatures, whereas under cold stress only root biomass was significantly increased by inoculation. AMF supplied P to the host plant under ambient temperatures and cold stress, as evidenced by the higher P content of mycorrhizal plants compared with non-mycorrhizal plants. Thus, the cold-stressed cucumber seedlings still benefited from mycorrhiza, although the benefit was less than that under ambient temperatures. In accordance with this, a cucumber Pi transporter gene belonging to the Pht1 gene family was strongly induced by mycorrhiza at ambient temperature and to a lesser extent under cold stress. The other three Pi transporters tested from different families were most highly expressed in cold-stressed mycorrhizal plants, suggesting a complex interactive effect of mycorrhiza and cold stress on internal P cycling in cucumber plants.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Abeer Hashem ◽  
E. F. Abd_Allah ◽  
A. A. Alqarawi ◽  
A. A. Al-Huqail ◽  
M. A. Shah

The role of soil microbiota in plant stress management, though speculated a lot, is still far from being completely understood. We conducted a greenhouse experiment to examine synergistic impact of plant growth promoting rhizobacterium,Bacillus subtilis(BERA 71), and arbuscular mycorrhizal fungi (AMF) (Claroideoglomus etunicatum;Rhizophagus intraradices; andFunneliformis mosseae) to induce acquired systemic resistance in Talh tree (Acacia gerrardiiBenth.) against adverse impact of salt stress. Compared to the control, the BERA 71 treatment significantly enhanced root colonization intensity by AMF, in both presence and absence of salt. We also found positive synergistic interaction betweenB.subtilisand AMFvis-a-visimprovement in the nutritional value in terms of increase in total lipids, phenols, and fiber content. The AMF and BERA 71 inoculated plants showed increased content of osmoprotectants such as glycine, betaine, and proline, though lipid peroxidation was reduced probably as a mechanism of salt tolerance. Furthermore, the application of bioinoculants to Talh tree turned out to be potentially beneficial in ameliorating the deleterious impact of salinity on plant metabolism, probably by modulating the osmoregulatory system (glycine betaine, proline, and phenols) and antioxidant enzymes system (SOD, CAT, POD, GR, APX, DHAR, MDAHR, and GSNOR).


2020 ◽  
Vol 110 (5) ◽  
pp. 999-1009 ◽  
Author(s):  
Golam Jalal Ahammed ◽  
Qi Mao ◽  
Yaru Yan ◽  
Meijuan Wu ◽  
Yaqi Wang ◽  
...  

Melatonin is a multifunctional molecule that confers tolerance to a number of biotic and abiotic stresses in plants. However, the role of melatonin in plant response to Fusarium oxysporum and the interaction with arbuscular mycorrhizal fungi (AMF) remain unclear. Here we show that exogenous melatonin application promoted the AMF colonization rate in cucumber roots, which potentially suppressed Fusarium wilt as evidenced by a decreased disease index and an increased control effect. Leaf gas exchange analysis revealed that Fusarium inoculation significantly decreased the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentrations (Ci), and transpiration rate (Tr). Intriguingly, either melatonin application or AMF inoculation significantly increased the Pn, Gs, Tr, and dry biomass, and their combined treatment showed a more profound effect under Fusarium stress. Further analysis showed that Fusarium induced oxidative stress as evidenced by increased lipid peroxidation and electrolyte leakage. Conversely, either melatonin or AMF drastically attenuated the levels of malondialdehyde, H2O2, and electrolyte leakage in Fusarium-inoculated plants, and their combined treatment caused a further decrease. Fusarium inoculation decreased the activity and transcripts of superoxide dismutase and ascorbate peroxidase, and the content of glutathione and proline. Besides, the activity and transcripts of peroxidase and catalase, the content of phenols and flavonoids increased after Fusarium infection. Importantly, melatonin and/or AMF significantly increased those parameters with the greatest effect with their combined treatment under Fusarium stress. Our results suggest that a positive collaboration between melatonin and AMF enhances resistance to Fusarium wilt in cucumber plants.


2006 ◽  
Vol 144 (2) ◽  
pp. 782-792 ◽  
Author(s):  
Cristina Cruz ◽  
Helge Egsgaard ◽  
Carmen Trujillo ◽  
Per Ambus ◽  
Natalia Requena ◽  
...  

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