Diversity of cultivable endophytic bacteria associated with halophytes in Xinjiang of China and their plant beneficial traits

Abstract

Endophytic bacteria from halophytes have a wide range of application prospects in various fields, such as plant growth-promoting, biocontrol activity and stress resistance. The current study aimed to identify cultivable endophytic bacteria associated with halophytes grown in the salt-affected soil in Xinjiang Uygur Autonomous Region, China and to evaluate their plant beneficial traits and enzyme-producing activity. Endophytic bacteria were isolated from Reaumuria soongorica (PalL Maxim.), Artemisia carvifolia (Buch.-Ham. ex Roxb. Hort. Beng.), Peganum harmala L. and Suaeda dendroides (C. A. Mey. Moq.) by using the cultural-dependent method. Then we classified these bacteria based on the difference between their sequences of 16S rRNA (16S ribosomal RNA) gene. Results showed that the isolated bacteria from R. soongorica belonged to the genera Brucella, Bacillus and Variovorax. The bacteria from A. carvifolia belonged to the genera Micromonospora and Brucella. The bacteria from P. harmala belonged to the genera Paramesorhizobium, Bacillus and Peribacillus. The bacteria from S. dendroides belonged to the genus Bacillus. Notably, the genus Bacillus was detected in the three above plants, indicating that Bacillus is a common taxon of endophytic bacteria in halophytes. And, our results found that about 37.50% of the tested strains showed strong protease-producing activity, 6.25% of the tested strains showed strong cellulase-producing activity and 12.50% of the tested strains showed moderate lipase-producing activity. Besides, all isolated strains were positive for IAA (3-Indoleacetic acid) production, 31.25% of isolated strains exhibited a moderate phosphate solubilization activity and 50.00% of isolated strains exhibited a weak siderophore production activity. Our findings suggest that halophytes are valuable resources for identifying microbes with the ability to increase host plant growth and health in salt-affected soils.

Diversity and Plant Growth-Promoting Ability of Endophytic, Halotolerant Bacteria Associated with Tetragonia tetragonioides (Pall.) Kuntze

“…There are numerous reports and abundant evidence about improved growth, development, and stress tolerance of plants in natural environments or under induced salinity provided by halotolerant, plant-beneficial endophytic bacteria. Such bacteria, associated with Psoralea corylifolia [ 45 ] and Lycium ruthenicum [ 46 ], enhanced stress tolerance and the development of wheat. Halotolerant B. alcalophilus and B. thuringiensis isolated from Arthrocnemum macrostachyum (Moric.)…”

The Antibacterial, Antitumor Activities, and Bioactive Constituents’ Identification of Alectra sessiliflora Bacterial Endophytes

“…have previously been isolated from tomato roots (Zhu et al, 2021), rice roots (Khaskheli et al, 2020;Shabanamol et al, 2021); and Peribacillus spp. was previously isolated from P. harmala (Li et al, 2021) and canola crop roots (Martínez-Hidalgo et al, 2021), making our study one of the few to isolate and report Peribacillus sp. as an endophyte.…”

“…Although five bacterial endophytes were isolated in this study, the data adds to the minimally reported phyllosphere bacterial endophytes ( Sivakumar et al, 2020 ). Li et al (2021) , reported a minimal number of bacterial endophytes from halophytes, with five bacterial endophytes isolated each from Reaumuria soongorica (PalL Maxim.) and Peganum harmala L., and three bacterial endophytes each from Artemisia carvifolia (Buch-Ham.…”

“…was previously isolated from P . harmala ( Li et al, 2021 ) and canola crop roots ( Martínez-Hidalgo et al, 2021 ), making our study one of the few to isolate and report Peribacillus sp. as an endophyte.…”

Production of indole-3-acetic acid by endophytic fungi of halophyte plants under salt stress

“…There are reports that, for example, co-evolution occurs between salt-tolerant plants and endophytes. Host plants can provide suitable habitat and abundant nutrients for endophytes, while endophytes can promote host plant growth by fixing nitrogen releasing auxin and other secondary metabolites [4].…”