Plant hosts may influence arbuscular mycorrhizal fungal community composition in mangrove estuaries

Abstract

We investigated the role of plant host and soil variables in determining arbuscular mycorrhizal fungi (AMF) community composition in plant roots of two spatially separated mangrove estuaries on the rivers Aghanashini (14°30′30″N-74°22′44″E) and Gangavali (14°35′26″N-74°17′51″E) on the west coast of India. Both mangrove estuaries had similar plant species composition but differed in soil chemistries.We amplified a 550 bp portion of 18S small subunit (SSU) rDNA from mangrove plant roots and analysed it by restriction fragment length polymorphism (RFLP). Clones representing unique RFLP patterns were sequenced. A total of 736 clones were obtained from roots of seven and five plant species sampled at Aghnashini and Gangavali, respectively. AMF phylotype numbers in plant roots at Aghanashini (12) were higher than at Gangavali (9) indicating quantitative differences in the AMF community composition in plant roots at the two mangrove estuaries.Because both estuaries had similar plant species composition, the quantitative difference in AMF communities between the estuaries could be an attribute of the differences in rhizospheric chemistry between the two sites.Non-metric multidimensional scaling (NMDS) revealed overlap in the AMF communities of the two sites. Three and two AMF phylotypes had significant indicator value indices with specific hosts at Aghanashini and Gangavali respectively. Environmental vector fitting to NMDS ordination did not reveal a significant effect of any soil variable on AMF composition at the two sites. However, significant effects of both plant hosts and sites were observed on rhizospheric P.Our results indicate that root AMF community composition may be an outcome of plant response to rhizospheric variables. This suggests that plant identity may have a primary role in shaping AMF communities in mangroves.

Genetic diversity and community composition of arbuscular mycorrhizal fungi associated with root and rhizosphere soil of the pioneer plant Pueraria phaseoloides

“…This divergence seems likely due to the strong regulation of the plant host on the rhizosphere species pool via root exudates, thereby masking soil conditions in structuring the soil AMF communities. In line with other studies, it was demonstrated that the host plant exerts a much stronger selectivity for AMF colonization of roots than prevailing soil conditions [13,47,48]. This confirms the acknowledged community assembly concept of AMF, whereby the host filter was decisive for AMF assemblage within the plant [7].…”

“…However, the symbiosis between plants and AMF is generally considered as nonspecific [43], which ascribes the small number of characterized AMF species (~300) compared to that of plant species (~300,000) [44]. Nevertheless, evidence exists that a preference of AMF-plant associations was present in different ecosystems [13,14,44].…”

“…However, the symbiosis between plants and AMF is generally considered as nonspecific [ 43 ], which ascribes the small number of characterized AMF species (~300) compared to that of plant species (~300,000) [ 44 ]. Nevertheless, evidence exists that a preference of AMF‐plant associations was present in different ecosystems [ 13 , 14 , 44 ]. Apart from the release of carbonaceous root exudates triggering the most preferred symbiont [ 45 ], soil conditions have been acknowledged to modify the ability of plants to attract selected AMF [ 46 ].…”

“…This divergence may be the result of having targeted different ecosystems, host plants and sample types (Supporting Information: Table S1 ). More importantly, plants exert strong effects on the diversity and composition of their asscociated AMF [ 12 , 13 ], but the specificity of the association between plant host and AMF taxa is generally low [ 14 ]. In addition, the same plant species may reveal differences in AMF communities between plant compartments, that is, root and rhizosphere soil [ 15 , 16 , 17 , 18 ].…”

Seasonal Dynamics of Arbuscular Mycorrhizal Fungi from Iron Ore Mine Wastelands of Goa, India

“…Studies on seasonal fluctuations in AM fungal communities in response to climatic and edaphic factors have been documented earlier (Alguacil et al, 2016;Halder et al, 2015;Deepika and Kothamasi 2015;Melo et al, 2019). Similarly, studies on the occurrence of AM fungi from different mine spoils have been reported earlier (Sastry and Johri, 1999;Teixeira et al, 2017;Rodríguez et al, 2021;Bukhari and Rodrigues, 2022).…”