Functional Characterization of a Magnesium Transporter of Root Endophytic Fungus Piriformospora indica

Abstract

Magnesium (Mg) is a crucial macronutrient required for the regular growth of plants. Here we report the identification, isolation and functional characterization of Mg-transporter PiMgT1 in root endophytic fungus Piriformospora indica. We also report the role of P. indica in the improvement of the Mg nutrition of the plant particularly under Mg deficiency condition. Protein BLAST (BLASTp) for conserved domains analysis showed that PiMgT1 belong to CorA like protein family of bacteria. We have also observed the presence of conserved ‘GMN’ signature sequence which suggests that PiMgT1 belongs to Mg transporter family. Phylogenetic analysis revealed that PiMgT1 clustered among fungal CorA family members nearer to basidiomycetes. Functionality of PiMgT1 was confirmed by complementation of a yeast magnesium transporter mutant CM66. We have observed that PiMgT1 restored the growth of mutant and showed comparable growth with that of WT. We found statistically significant (p < 0.05) two fold increase in the total intracellular Mg content of mutant complemented with PiMgT1 as compared to the mutant. These observations suggest that PiMgT1 is actively involved in Mg uptake by the fungus and may be helping in the nutritional status of the host plant.

Metal transporters in organelles and their roles in heavy metal transportation and sequestration mechanisms in plants

“…Additionally, mycorrhizal symbioses are also an effective bio‐tool in mitigating heavy metal stress and nutrient uptake. These symbioses tolerate metal toxicity by well‐managed metal homeostasis and metal biofortification in plants (Ferrol et al, 2016; Narayan et al, 2017; Prasad et al, 2019). Thus, different transport systems are interdependent on different nutrients level and always try to maintain homeostasis, which goes beyond molecule specificities in terms of regulation.…”

K+ Nutrition Exchange in the Serendipita-Arabidopsis Symbiosis: Study of the Fungal K+ Transporters Involved

“…It has demonstrated beneficial effects on plant growth under both biotic and abiotic conditions such as drought and saline conditions (Waller et al, 2005;Ghaffari et al, 2016;Jogawat et al, 2016;Abdelaziz et al, 2017;Li et al, 2017;Zhang et al, 2018;Ghorbani et al, 2019). However, although recently progress is being made in the knowledge of the nutrition of certain micronutrients such as magnesium, iron and sulfur (Prasad et al, 2019;Narayan et al, 2021;Verma et al, 2021), there is not much information available on the contribution of this endophyte to the plant nutrition of the main macronutrients, as previous studies to determine its role in plant P nutrition have obtained contradictory results. Although there are data indicating that S. indica does not play any role in the supply of Pi in the symbiosis with barley (Achatz et al, 2010), it has been found that S. indica enhances plant growth by transferring phosphate to host maize plants (Yadav et al, 2010).…”

Comparative Genomics of Exiguobacterium Reveals What Makes a Cosmopolitan Bacterium

“…In addition, 2 of the 25 families are involved in the transport of Mg 2+ , namely, the cyclin M Mg 2+ exporter family and the CorA metal ion transporter family. Mg 2+ homeostasis is important in bacteria and has been reported to play a critical role in their thermotolerance ( 47 , 48 ). The inorganic phosphate transporter family was also found to be expanded in group I relative to group II ( Table 1 ).…”