Salinity of irrigation water selects distinct bacterial communities associated with date palm (Phoenix dactylifera L.) root

Abstract

Saline water irrigation has been used in date palm (Phoenix dactylifera L.) agriculture as an alternative to non-saline water due to water scarcity in hyper-arid environments. However, the knowledge pertaining to saline water irrigation impact on the root-associated bacterial communities of arid agroecosystems is scarce. In this study, we investigated the effect of irrigation sources (non-saline freshwater vs saline groundwater) on date palm root-associated bacterial communities using 16S rDNA metabarcoding. The bacterial richness, Shannon diversity and evenness didn’t differ significantly between the irrigation sources. Soil electrical conductivity (EC) and irrigation water pH were negatively related to Shannon diversity and evenness respectively, while soil organic matter displayed a positive correlation with Shannon diversity. 40.5% of total Operational Taxonomic Units were unique to non-saline freshwater irrigation, while 26% were unique to saline groundwater irrigation. The multivariate analyses displayed strong structuring of bacterial communities according to irrigation sources, and both soil EC and irrigation water pH were the major factors affecting bacterial communities. The genera Bacillus, Micromonospora and Mycobacterium were dominated while saline water irrigation whereas contrasting pattern was observed for Rhizobium, Streptomyces and Acidibacter. Taken together, we suggest that date-palm roots select specific bacterial taxa under saline groundwater irrigation, which possibly help in alleviating salinity stress and promote growth of the host plant.

Abiotic and biotic factors influencing small-scale corn production along a shade spectrum in arid urban agriculture settings

“…This is also a potential avenue for the observed dominance of the genus Acidibacter in corn plot soils, a potential iron reducing group that may enhance iron availability to plant roots [ 55 ]. In arid region date palm agriculture, Acidibacter was found to be more abundant in soils irrigated with non-saline freshwater (analogous to treated city water) vs saline groundwater [ 56 ]. The long term application of bio-compost in circumneutral soils has also been shown to enrich the relative abundance of beneficial microbes such as Acidibacter while reducing harmful soil microbes [ 57 ], and the organic management practices employed in this study’s corn plots do incorporate bio-compost derived soils.…”

Harnessing rhizospheric core microbiomes from arid regions for enhancing date palm resilience to climate change effects

“…Furthermore, date palms exhibit a notable tolerance to salinity levels, commonly ranging from 4 to 8 dS/m or even higher under specific conditions (Muller et al, 2017;Alotaibi et al, 2023). Nevertheless, the irrigation of date palm with saline groundwater, due to water scarcity, is a common practice in the MENA regions, which threatens the sustainability of date palm cultivation (Shamim et al, 2022;Sanka Loganathachetti and Mundra, 2023).…”

“…They identified two major endophytic bacterial phyla, Gammaproteobacteria and Alphaproteobacteria, known to perform ecological functions of biopromotion and biofertilization in harsh environments. Shamim et al (2022) demonstrated that Micromonospora and Mycobacterium bacterial taxa were effective in alleviating salinity stress when date palms were irrigated with saline water. Cherif et al (2015) further showed that Gammaproteobacteria, a class of endophytic bacteria isolated from date palm, was also effective in improving plant drought tolerance.…”

“…Up-to-date, there are few reports addressing date palm microbial profiling (Ferjani et al, 2015;Yaish et al, 2016;Mosqueira et al, 2019;Chebaane et al, 2020;Al-busaidi et al, 2022;Shamim et al, 2022). Few of them go deeper beyond the species identification level.…”

Editorial: Plant microbiome: Ecology, functions, and application trends

“…Moreover, plant characteristics such as root and shoot morphology and anatomy can change nutrient availability and associated microbiome ( Lynch, 2019 ). Host genetics and environmental factors greatly influence the selection and structure of the plant microbiome ( Morella et al., 2020 ; Shamim et al., 2022 ). Soil geochemistry, plant genetics, and physiological response significantly influence the root microbiome ( Bulgarelli et al., 2012 ; Lundberg et al., 2012 ; Schlaeppi et al., 2014 ; Edwards et al., 2015 ).…”