Investigation of Microbial Community Structure and Diversity in the Rhizosphere of Date Palm (Phoenix Dactylifera L.), Sukkari Cultivar

Abstract

The rhizosphere microbial community of a plant plays a pivotal role in mediating plant and soil health. This study was conducted to unravel the rhizosphere microbial structure and community of Sukkari date palm trees. The soil collected from the rhizosphere was subjected to metagenomic analysis. The results revealed that most of the sequences (62%) were identified as bacteria: 48% were unknown bacteria, 5% were Actinobacteria, and 9% were Proteobacteria. Microorganisms belonging to eukaryotes were 25% of the microbial community, represented by 21% Streptophyta and 4% Ciliopora and 5% of the sequences were Archaea. These analyses were followed by functional enzyme analysis, which identified microbial metabolism in diverse environments related to nine carbohydrate and energy pathways; seven pathways were associated with degradation, and nine metabolic pathways were associated with amino acid metabolism. The comparison of community analysis with our previous study provided distinct differences even in the same plants with various cultivars.

The effect of type and combination of fertilizers on eukaryotic microbiome of date palm rhizosphere

“…The observed OTUs, Shannon index, and Chao1 richness estimates of soil samples from date palm and acid limes had higher fungal diversity than soil samples from cucumbers in a semi-Oasis farm in Oman (Kazeeroni and Al-Sadi 2016). In a study on the microbiome of date palms in an oasis in Saudi Arabia, Streptophyta dominated in Sukkari cultivars and was absent in Khalas cultivars while Ascomycota dominated Khalas cultivars and was absent in Sukkari cultivars (Dhawi and Alsanie 2022). In another study at a semi-oasis farm and organic farm in Oman, Ascomycota was the most dominant phylum in most samples (date palm, acid limes, cucumber, and tomato) (Kazeeroni and Al-Sadi 2016).…”

The Role of Plant Growth-Promoting Microorganisms (PGPMs) and Their Feasibility in Hydroponics and Vertical Farming

“…The soil microorganisms of plant roots are divided into three sections—the rhizosphere, rhizoplane, and endosphere [ 21 , 26 ]—which usually influence an area of several centimeters around the plant’s roots with density ranges from 10 8 to 10 11 colony-forming units (CFUs) per gram of root [ 26 ]. A study conducted on samples of the rhizosphere of the Khalas date palm showed that the majority of the identified sequences (86%) belonged to bacteria [ 6 , 7 , 8 ]. Another study analyzed the rhizosphere of two cultivars of the Khalas date palm and found that the rhizosphere of the Sukkari and Khalas cultivars possessed 62% and 86% bacteria, respectively [ 6 , 7 , 8 ].…”

“…A study conducted on samples of the rhizosphere of the Khalas date palm showed that the majority of the identified sequences (86%) belonged to bacteria [ 6 , 7 , 8 ]. Another study analyzed the rhizosphere of two cultivars of the Khalas date palm and found that the rhizosphere of the Sukkari and Khalas cultivars possessed 62% and 86% bacteria, respectively [ 6 , 7 , 8 ]. Microbes stimulate and protect plants, while plants in turn provide nutrients to microbes; this relationship is not only for survival purposes, but also for prominent benefits such as phytoremediation.…”

“…Their positive functions include increasing the growth and subsequent metabolic pathways in poor soil with low nutrient levels, and increasing plant tolerance and the phytoremediation ability in polluted soil [ 2 , 3 , 4 , 5 ]. Some microorganisms play an additional role as metagenome signatures for some plant species, such as different date palm and millet cultivars [ 3 , 6 , 7 , 8 ].…”

“…Considering that plant growth-promoting microorganisms (PGPMs) have been known for decades to enhance plant health and increase productivity [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ], the questions are “what is the added value for PGPM incorporation in vertical farming or hydroponics?” and “what is the best mode of use considering a soil-free system?”…”