Salinity altered root distribution and increased diversity of bacterial communities in the rhizosphere soil of Jerusalem artichoke

Abstract

The interaction between roots and bacterial communities in halophytic species is poorly understood. Here, we used Jerusalem artichoke cultivar Nanyu 1 (NY-1) to characterise root distribution patterns and determine diversity and abundance of bacteria in the rhizosphere soil under variable salinity. Root growth was not inhibited within the salinity range 1.2 to 1.9 g salt/kg, but roots were mainly confined to 0–20 cm soil layer vertically and 0–30 cm horizontally from the plant centre. Root concentrations of K+, Na+, Mg2+ and particularly Ca2+ were relatively high under salinity stress. High salinity stress decreased soil invertase and catalase activity. Using a next-generation, Illumina-based sequencing approach, we determined higher diversity of bacteria in the rhizosphere soil at high than low salinity. More than 15,500 valid reads were obtained, and Proteobacteria, Acidobacteria, Bacteroidetes and Actinobacteria predominated in all samples, accounting for >80% of the reads. On a genus level, 636 genera were common to the low and high salinity treatments at 0–5 cm and 5–10 cm depth. The abundance of Steroidobacter and Sphingomonas was significantly decreased by increasing salinity. Higher Shannon and Chao 1 indices with increasing severity of salt stress indicated that high salt stress increased diversity in the bacterial communities.

Bacterial community structure and function shift along a successional series of tidal flats in the Yellow River Delta

“…Salinity can change physicochemical properties and microbial community composition in the sediment. High salinity can directly suppress the heterotrophic metabolic capabilities3437, and decrease the diversity of heterotrophic bacteria species, such as Beta-proteobacteria, Chloroflexi, and Bacteroidetes38. Our results are consistent with earlier findings that salinity could affect the spatial changes of bacterial community structure in the tidal flats in the Yellow River Delta…”

“…This result is similar to a pervious study in the Yellow River Delta38. It could be explained by the low nutrient content in the Yellow River Delta that inhibits the growth of Cyanobacteria1839.…”

“…Our results showed the bacterial community responses to low temperature in tidal flats, especially in the subtidal flat. Similar observations have been reported for marine and lake ecosystems121538. These functional profiles in subtidal flat in winter were generally found at low temperature, high ionic concentration, and poor nutrient conditions314244, indicating that the bacterial community function in the subtidal flat was impaired in winter.…”

Assessment of Culturable Microbial Diversity Associated with Arnebia euchroma: A Critically Endangered Plant Growing in Trans-Himalayas of Himachal Pradesh, India

“…Salt stress was found to increase the diversity of rhizosphere bacterial communities in the rhizosphere of halophyte plants (Yang et al, 2016).The electrical conductivity values of soils under study reveals that soils are low in soluble salts concentration with EC values ranged from 0.109 to 0.222 dScm -1 which might be attributed to slow microbial activities under prevailing low temperature conditions. Considering the organic carbon content <0.5 % as low, 0.5 -1.0 per cent medium and > 1% high, respectively, the tested soil samples fall under medium and high organic carbon content category, with medium organic carbon contents both at Chango (0.75) and Gue (0.60) and high at Nako(1.20).…”

Influence of salt content on enzymatic activities and halophytes distribution in Cojocna zone, Romania

“…It is known that microorganisms contribute to soil enzyme composition, but this composition is completed by animals and plants. Soil enzyme activity constitutes a main indicator for soil quality, especially regarding different types of pollution (Yang et al, 2016). High-salinity in soil, sometimes caused by saline groundwater, impedes the germination and growth of plants Guo and Liu, 2014).…”