New Insights into the Synergistic Interaction Between Pseudomonas qingdaonensis NZ 1 and Silicon to Mitigate Drought Stress in Rice

Nazree Zainurin; Muhammad Imran; Shifa Shaffique; Muhammad Aaqil Khan; Sang-Mo Kang; Md Injamum-Ul-Hoque; Ashim Kumar Das; Byung-Wook Yun; In-Jung Lee

doi:10.3390/microorganisms13051046

New Insights into the Synergistic Interaction Between Pseudomonas qingdaonensis NZ 1 and Silicon to Mitigate Drought Stress in Rice

Microorganisms. 2025 Apr 30;13(5):1046. doi: 10.3390/microorganisms13051046.

Authors

Nazree Zainurin¹, Muhammad Imran², Shifa Shaffique¹, Muhammad Aaqil Khan³, Sang-Mo Kang¹, Md Injamum-Ul-Hoque¹, Ashim Kumar Das¹, Byung-Wook Yun¹, In-Jung Lee¹

Affiliations

¹ Department of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea.
² Biosafety Division, National Institute of Agriculture Science, Rural Development Administration, Jeonju 54874, Republic of Korea.
³ Department of Chemical and Life Sciences, Qurtuba University, Peshawar 25000, Pakistan.

Abstract

The current study assessed the synergistic effects of PGPR and Si in alleviating drought stress in rice. Bacteria were isolated from Phragmites australis inhabiting an urban riverbank. Among the isolated strains, Pseudomonas qingdaonensis NZ 1 showed promising results under in vitro drought stress induced by PEG-6000 (-0.28 MPa). To further investigate the synergistic effect of Pseudomonas qingdaonensis NZ 1 and silicon, a plant growth experiment was conducted comprising the control (dH₂O) and plants treated with NZ 1, Si (1 mM), and NZ 1+Si under normal and drought stress conditions. The results revealed that NZ 1+Si-treated plants showed improved plant growth parameters, chlorophyll contents, relative water contents, antioxidant potential, and nutrient uptake under normal and drought conditions. Moreover, endogenous abscisic acid and jasmonic acid levels were substantially reduced, while the salicylic acid level was increased in NZ 1+Si-treated plants. Moreover, the relative expression of the ABA metabolic genes OsNCED3 and OsCYP707A6 and transcription factors OsbZIP23 and OsDREB1B were significantly altered. Furthermore, the leaf Si, calcium, potassium, and phosphorus contents were increased in NZ 1+Si-treated drought-stressed plants, along with the upregulation of OsLSi1. The combined application of NZ 1 and Si offers a sustainable agricultural strategy to effectively mitigate the detrimental effects of drought.

Keywords: PGPR; drought stress; phytohormones; plant–microbe interaction; reactive oxygen species; silicon; synergism.