Streptomyces hygroscopicus OsiSh-2-induced mitigation of Fe deficiency in rice plants

• Published in: Plant physiology and biochemistry Vol. 158; pp. 275 - 283
• Main Authors: Cao, Lidan, Gao, Yan, Yu, Jinlan, Niu, Shuqi, Zeng, Jiarui, Yao, Qingqing, Wang, Xiang, Bu, Zhigang, Xu, Ting, Liu, Xuanming, Zhu, Yonghua
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.01.2021
• Subjects: Endophyte; Endophytes - physiology; Fe acquisition; Fe deficiency; Iron - deficiency; Oryza - microbiology; Oryza - physiology; Plant-microbe interactions; Rice (oryza); Siderophores; Streptomyces - physiology; Streptomyces hygroscopicus; Stress resilience; Stress resilience; Streptomyces hygroscopicus; Fe deficiency; Endophyte; Plant-microbe interactions; Fe acquisition; Rice (oryza)
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2020.11.013

The limited availability of nutrient Fe severely impairs the health of almost all organisms. Endophytic actinobacteria can benefit the host plant in different ways. We previously inferred that the rice (Oryza) endophytic Streptomyces hygroscopicus OsiSh-2 possesses a highly efficient Fe-acquisition system. In this work, we first evaluated the effects of OsiSh-2 on the Fe-deficiency resilience of the host rice. The results demonstrated that the inoculation of OsiSh-2 considerably increased the plant biomass, Fe concentration and translocation factor, and chlorophyll content, and net leaf photosynthetic rate under Fe limiting condition. The expression of genes involved with Fe3+-reduction-related strategy in rice was up-regulated, while that involved with Fe3+-chelation-related strategy was down-regulated by OsiSh-2 treatment. Meanwhile, the OsiSh-2-rice symbiont showed enhancement of Fe3+-chelate reductase activity, total siderophore production, and acidification trend in the rhizosphere under Fe deficiency compared to plants without this endophyte. In conclusion, endophytic OsiSh-2 could protect plants against Fe-deficient stress by a sophisticated interaction with the host, including modulating Fe chelation, solubilization, reduction and translocation, ultimately leading to enhanced fitness of plant. [Display omitted] •Endophytic Streptomyces hygroscopicus OsiSh-2 enhanced rice tolerance to Fe deficiency.•OsiSh-2 modified root architecture, photosynthesis, Fe absorption and translocation of rice under Fe deficiency conditions.•OsiSh-2-rice interaction involving two Fe-acquisition processes enhanced Fe-deficiency resilience in rice.•OsiSh-2 has the potential to be utilized as a biofertilizer in rice cultivation.