TY - JOUR
T1 - Water pH, not soil pH, alters bacterial community structural pattern and nitrogen cycling pathways in date palm (Phoenix dactylifera L.) roots and bulk soil under freshwater irrigation regime
AU - Sanka Loganathachetti, Dinesh
AU - Mundra, Sunil
N1 - Publisher Copyright:
Copyright © 2023 Sanka Loganathachetti and Mundra.
PY - 2023
Y1 - 2023
N2 - Date palms are widely cultivated in arid agroecosystems, where knowledge of irrigation water effect on their soil and root-associated bacterial communities is limited. Using 16S rDNA metabarcoding, we studied soil and root-associated bacterial communities of date palms growing in United Arab Emirates. Overall, 12.18% of bacterial operational taxonomic units (OTUs) were unique to roots, whereas 41.55% were specific to soil. The bacterial diversity was lower in root and community patterns were distinct between compartments, wherein irrigation water pH was a key structuring factor in both compartments, while salinity (electrical conductivity) was important only in the soil. Co-occurrence network analysis revealed a decrease in complexity in the soil–root continuum, and specific taxa/modules also varied with water pH. We observed a higher abundance of endophyte–saprotroph (Bacillus, Streptomyces and Dongia) dual-role OTUs in both compartments, possibly involved in nutrient mobilisation and plant growth. Based on PICRUSt and trait-based analyses, we showed that these OTUs are putatively involved in the nitrogen cycle (nitrification, denitrification, and assimilatory nitrate reduction). Taken together, we suggest that irrigation water pH, not soil pH, transiently affects belowground bacterial communities and selects bacteria in specific pH ranges, which may be important for nutrient cycling (i.e. nitrogen cycle) in arid agroecosystems.
AB - Date palms are widely cultivated in arid agroecosystems, where knowledge of irrigation water effect on their soil and root-associated bacterial communities is limited. Using 16S rDNA metabarcoding, we studied soil and root-associated bacterial communities of date palms growing in United Arab Emirates. Overall, 12.18% of bacterial operational taxonomic units (OTUs) were unique to roots, whereas 41.55% were specific to soil. The bacterial diversity was lower in root and community patterns were distinct between compartments, wherein irrigation water pH was a key structuring factor in both compartments, while salinity (electrical conductivity) was important only in the soil. Co-occurrence network analysis revealed a decrease in complexity in the soil–root continuum, and specific taxa/modules also varied with water pH. We observed a higher abundance of endophyte–saprotroph (Bacillus, Streptomyces and Dongia) dual-role OTUs in both compartments, possibly involved in nutrient mobilisation and plant growth. Based on PICRUSt and trait-based analyses, we showed that these OTUs are putatively involved in the nitrogen cycle (nitrification, denitrification, and assimilatory nitrate reduction). Taken together, we suggest that irrigation water pH, not soil pH, transiently affects belowground bacterial communities and selects bacteria in specific pH ranges, which may be important for nutrient cycling (i.e. nitrogen cycle) in arid agroecosystems.
KW - arid agroecosystems
KW - co-occurrence network
KW - date palms (Phoenix dactylifera L.)
KW - irrigation water
KW - nitrogen cycle
KW - root and soil bacterial community
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U2 - 10.3389/fevo.2023.1142073
DO - 10.3389/fevo.2023.1142073
M3 - Article
AN - SCOPUS:85164391301
SN - 2296-701X
VL - 11
JO - Frontiers in Ecology and Evolution
JF - Frontiers in Ecology and Evolution
M1 - 1142073
ER -