|ZHU, FENG - Jilan University|
|WANG, JICHUN - Jilan University|
|TIAN, CHENGLI - Jilan University|
|ZHAO, DI - Shenyang Agricultural University|
|WU, XIAN - Jilan University|
|LIU, YANNI - Jilan University|
|JIANG, ZHAOYUAN - Jilan University|
|LIU, XIAOMEI - Jilan University|
|LI, LI - Jilan University|
|REN, JINPING - Jilan University|
|SUN, HUI - Jilan University|
|DONG, YINGSHAN - Jilan University|
Submitted to: Phytofrontiers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2020
Publication Date: 5/17/2021
Citation: Zhu, F., Wang, J., Jia, Y., Tian, C., Zhao, D., Wu, X., Liu, Y., Jiang, Z., Liu, X., Li, L., Ren, J., Sun, H., Dong, Y. 2021. Bacillus subtilis GB519 promotes rice growth and reduces the damages caused by rice blast fungus magnaporthe oryzae. Phytofrontiers. https://doi.org/10.1094/PHYTOFR-12-20-0041-R.
Interpretive Summary: Blast disease of rice is one of the most challenging diseases that significantly impacts stable rice production worldwide. Beneficial microbes associated with rice roots can be found to help plant growth and reduce the damages by rice blast fungus. In this study, we identified and isolated bacteria Bacillus subtilis GB519 from the rhizosphere soils of rice paddy and showed that GB519 promoted plant growth and inhibited 9 fungal pathogens of rice in vitro. Among them, the greatest inhibition was observed for rice blast fungus. Under greenhouse conditions after rice was exposed to GB519 twice we found that there were 70.3% and 69.9% reduction of blast disease that coincided with accumulated hydrolytic enzymes including amylases, proteases, chitinase and lipases, and the defense enzyme activity of the total antioxidant capacity (TAOC), catalase (CAT) and superoxide dismutase (SOD) in rice. These findings demonstrate that GB519 can be used as a biological control agent to control rice blast disease.
Technical Abstract: Rice blast disease caused by the fungus Magnaporthe oryzae (syn. Pyricularia oryzae) (M. oryzae) is one of the most lethal diseases of rice reducing plant growth and production worldwide. In the present study, Bacillus subtilis GB519 was identified from the rhizosphere soils based on predicted signatures of 16S rDNA, the gyrA gene, and morphological, biochemical and physiological characteristics. After treatment with B. subtilis GB519 rice exhibited an increased germination rate, vigor index, shoot length, shoot fresh weight, root fresh weight coupled with more production of Indole Acetic Acid (IAA), Porg and Phos. GB519 exhibited fungal growth inhibition most effectively on M. oryzae followed by Ustilaginoidea virens, Sclerotinia sclerotiorum, Borrytis cinereal, Colletetrichum lagenarium, Fusarium graminearum, F. moniliforme, F. oxysporum and Rhizoctonia solani in culture. Under greenhouse conditions after rice was exposed to GB519 twice we found that there were 70.3% and 69.9% reduction of blast disease incidences that correlated with accumulated hydrolytic enzymes including amylases, proteases, chitinase and lipases, and the defense enzyme activity of the total antioxidant capacity (TAOC), catalase (CAT) and superoxide dismutase (SOD) in rice. These results suggest that the strain B. subtilis GB519 promotes plant growth and reduces blast disease and can be used as a biological control agent against rice blast.