A Growth-Promoting Bacteria, Paenibacillus yonginensis DCY84T Enhanced Salt Stress Tolerance by Activating Defense-Related Systems in Panax ginseng

Abstract

Panax ginseng (C.A. Mayer) is a well-known medicinal plant used in traditional medicine in Korea that experiences serious salinity stress related to weather changes or incorrect fertilizer application. In ginseng, the use of Paenibacillus yonginensis DCY84T to improve salt stress tolerance has not been thoroughly explored. Therefore, we studied the role of P. yonginensis DCY84T under short-term and long-term salinity stress conditions in a controlled environment. In vitro testing of DCY84T revealed high indole acetic acid (IAA) production, siderophore formation, phosphate solubilization and anti-bacterial activity. We determined that 10-min dip in 1010 CFU/ml DCY84T was sufficient to protect ginseng against short-term salinity stress (osmotic stress) upon exposure to 300 mM NaCl treatment by enhancing nutrient availability, synthesizing hydrolyzing enzymes and inducing osmolyte production. Upon exposure to salinity stress (oxidative and ionic stress), strain DCY84T-primed ginseng seedlings were protected by the induction of defense-related systems such as ion transport, ROS scavenging enzymes, proline content, total sugars, and ABA biosynthetic genes, as well as genes involved in root hair formation. Additionally, ginseng primed with DCY84T and exposed to 300 mM NaCl showed the same metabolite profile as control ginseng plants, suggesting that DCY84T effectively reduced salt stress. These results indicated that DCY84T can be widely used as a microbial inoculant to protect ginseng plants against salinity stress conditions.

Sphingobacterium sp. BHU-AV3 Induces Salt Tolerance in Tomato by Enhancing Antioxidant Activities and Energy Metabolism

“…Four POD isoforms, two SOD isoforms, and four PPO isoforms with different molecular weights were significantly up-regulated in tomato plant roots inoculated with BHU-AV3 compared to un-inoculated plants under salt stress. The expression of multiple isoforms of antioxidant enzymes is involved in reducing the content of ROS and preventing the cell-damage (Kim et al, 2005;Zhang et al, 2013;Vighi et al, 2017;Arora and Bhatla, 2017;Sukweenadhi et al, 2018). In one study, new POD and SOD isoforms were expressed in response to salt stress tolerance in potato plants (Rahnama and Ebrahimzadeh, 2005).…”

Salt-Tolerant Halophyte Rhizosphere Bacteria Stimulate Growth of Alfalfa in Salty Soil

“…It is likely that different mechanisms are involved in each bacterial/plant interaction that leads to plant growth stimulation under saline conditions, and that a bacterial strain that stimulates growth of one plant species in the presence of salt may not cause similar stimulation in other plants. Some examples include ginseng, where Paenibacillus yonginensis strain DCY84 T protects against salinity stress by induction of defense related systems including ion transport, ROS enzyme production, proline content, total sugar and ABA biosynthesis related genes (Sukweenadhi et al, 2018). Another research group found that an endophytic strain of Bacilllus amyloliquefaciens produces ABA in response to increasing salinity, increasing production of glutamic acid and proline to increase resistance to salinity in rice (Shahzad et al, 2017).…”

Halo-tolerant plant growth promoting rhizobacteria for improving productivity and remediation of saline soils

“…UPMR18) enhanced the levels of SOD, APX, and CAT and triggered the regulation of genes involved in ROS pathway (CAT, APX, GR, and DHAR) in okra plants under salinity stress [31] . Priming of Panax ginseng with salt-tolerant Paenibacillus yonginensis DCY84 T facilitated the expression of various antioxidant genes such as PgAPX and PgCAT, increasing the plant tolerance against salinity stress [83] . Along with enzymatic ROS scavenging, HT-PGPR also produce non-enzymatic antioxidants such as ascorbate (AsA), carotenoids, tocopherols, glutathione (GSH) and phenolics which act as defense molecules for the plant under saline conditions [84] .…”