J Integr Plant Biol. ›› 2023, Vol. 65 ›› Issue (4): 1059-1076.DOI: 10.1111/jipb.13416

• Plant Biotic Interactions • Previous Articles     Next Articles

Heterosis in root microbiota inhibits growth of soil-borne fungal pathogens in hybrid rice

Mengting Zhang1,2, Yinyue Wang1,2,3, Yuanyi Hu4, Huacai Wang1,2, Yawen Liu1,2,3, Bingran Zhao4, Jie Zhang1, Rongxiang Fang1 and Yongsheng Yan1,2*   

  1. 1. State Key Laboratory of Plant Genomics, Institute of Microbiology, the Chinese Academy of Sciences, Beijing 100101, China;
    2. Innovation Academy for Seed Design, the Chinese Academy of Sciences, Beijing 100101, China;
    3. College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;
    4. State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, China
    *Correspondence: Yongsheng Yan (yanys@im.ac.cn)
  • Received:2022-10-09 Accepted:2022-11-24 Online:2022-11-25 Published:2023-04-01

Abstract: In nature, plants are colonized by various microbes that play essential roles in their growth and health. Heterosis is a natural genetic phenomenon whereby first‐generation hybrids exhibit superior phenotypic performance relative to their parents. It remains unclear whether this concept can be extended to the “hybridization” of microbiota from two parents in their descendants and what benefits the hybrid microbiota might convey. Here, we investigated the structure and function of the root microbiota from three hybrid rice varieties and their parents through amplicon sequencing analysis of bacterial 16S ribosomal DNA (rDNA) and fungal internal transcribed spacer (ITS) regions. We show that the bacterial and fungal root microbiota of the varieties are distinct from those of their parental lines and exhibit potential heterosis features in diversity and composition. Moreover, the root bacterial microbiota of hybrid variety LYP9 protects rice against soil‐borne fungal pathogens. Systematic analysis of the protective capabilities of individual strains from a 30‐member bacterial synthetic community derived from LYP9 roots indicated that community members have additive protective roles. Global transcription profiling analyses suggested that LYP9 root bacterial microbiota activate rice reactive oxygen species production and cell wall biogenesis, contributing to heterosis for protection. In addition, we demonstrate that the protection conferred by the LYP9 root microbiota is transferable to neighboring plants, potentially explaining the observed hybrid‐mediated superior effects of mixed planting. Our findings suggest that some hybrids exhibit heterosis in their microbiota composition that promotes plant health, highlighting the potential for microbiota heterosis in breeding hybrid crops.

Key words: heterosis, microbiota‐mediated protection, rice, root microbiota, synthetic community

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