Isolation and characterization of bacteria from tomato and assessment of its plant growth-promoting traits in three economically important crops in Al-Ahsa region, Saudi Arabia

Abstract

Aim: This study aimed to isolate, characterize and assess the plant growth-promoting traits of bacterial isolates inhabiting the rhizosphere of Solanum lycopersicum L. (tomato) against three plants—Eruca sativa, Lepidium sativum and Raphanus sativum—from Saudi Arabia's Al-Ahsa region. Methodology: bacterial isolate designated as SLK10 was obtained from the rhizosphere of tomato grown in the Al-Ahsa region, Saudi Arabia. SLK10 was further characterized morphologically, biochemically and genotypically using 16S rRNA gene sequencing. The roles in alleviating salt stress effects on three important economic crops were also assessed by implementing a cross-inoculation strategy. Results: SLK10 formed a circular, non-pigmented and raised colony with an entire margin. The cells were rod shaped and Gram negative. SLK10 displayed multiple plant growth-stimulating features, such as the solubilization of inorganic phosphate and the production of phytohormones and acetoin. Comparative sequence analysis of 16S rRNA gene revealed that SLK10 belonged to Pseudomonas monteilii, to which it exhibited 99.86% sequence homology. SLK10 significantly promoted the length of primary root, stem and number of leaves in Eruca sativa, Lepidium sativumand Raphanus sativus growing under 1000 ppm salt stress. The number of leaves in L. sativum and R. sativus growing under 2000 ppm salt stress was substantially enhanced by SLK10. Interpretation: SLK10 is a plant growth-promoting bacterium and can be used as a green fertilizer to increase soil fertility and plant productivity in the Eastern region of Saudi Arabia.

Whole-Genome Sequence Insight into the Plant-Growth-Promoting Bacterium Priestia filamentosa Strain AZC66 Obtained from Zygophyllum coccineum Rhizosphere

“…Phosphate-solubilizing bacteria play an important role in the availability of phosphorus to plants by secreting phosphatases and organic acids. These bacteria have also been shown to solubilize phosphate [ 22 , 23 ]. PGP helps plant roots absorb phosphorus for growth and productivity.…”

An update about plant growth promoting Streptomyces species

“…Brevibacterium casei [23], Streptomyces, Sinorhizobium [24], and Pseudomonas [25]. These bacteria vary in their mode of action, and therefore have utilizations as biofertilizers, biostimulators, biocontrol agents, and bioremediators.…”

Aplicación de técnicas moleculares en microbiología del suelo para la identificación de bacterias con potencial agrícola: una revisión y análisis bibliométrico

“…In this first cluster, there are the investigations that mention PGP bacterial genera such as Bacillus, Pseudo monas, and also the importance of the identification of microorganisms with mineral solubilizing potential, because often the availability of these nutrients in the soil is limited; based on this In another study, Gu et al (2020) isolated and characterized at the molecular level, employing sequencing and amplification of 16s rDNA using 27F and 1494R oligonucleotides in rhizospheric soil samples of tobacco plants; strain S58 identified as Pseudomonas mediterranea, showed significant antagonism against plant pathogenic fungi and bacteria and efficiently controlled acute eyespot of wheat. For their part, Aldayel and Khalifa (2021) identified Pseudomonas mon teilii in rhizospheric soil samples of tomato (Solanum lycopersicum L.) with 99.86% homologous regions by sequencing the 16s rRNA gene and applying the universal primers 27F and 1494R; the results evidenced that this strain significantly promoted primary root length, stem and leaf number in Eruca sativa (arugula) and Raphanus sativus (radish), growing under 1,000 mg kg -1 salt stress conditions. Finally, Aloo et al, (2020), investigated the diversity of cultivable rhizobacteria asso ciated with potato (Solanum tu berosum L.) in Tanzania; of the 152 isolates obtained, 52 of them were selected for molecular identification based on preliminary screening for PGP activities; thus for PCR amplification, primers 27F and 1492R were used; The results showed that the isolates were all Gammaproteobacteria, belonging to four families (Enterobacteriaceae, Yersiniaceae, Pseudomonadaceae and Morganellaceae) and nine genera (Enterobacter, Klebsiella, Serratia, Pseudomonas, Morganella, Buttiaux ella, Pantoea and Cedecea).…”