Every plant hosts a bustling community of microbes—on its leaves, roots, and surrounding soil—that play essential roles in growth and defense. Known as the plant microbiome, this hidden network is influenced by the plant’s genotype and environment. Kiwifruit (Actinidia spp.), prized for its high nutritional value, faces a serious threat from bacterial canker, a fast-spreading disease that severely affects yield and quality. Current treatments depend heavily on antibiotics and copper-based sprays, raising concerns about long-term sustainability. As researchers look for greener alternatives, attention has turned to the plant’s microbial partners. Due to these challenges, it is essential to explore how beneficial microbes can be harnessed to strengthen natural disease resistance.
A collaborative research team from Anhui Agricultural University and partnering institutes has made a breakthrough in understanding how beneficial microbes contribute to kiwifruit disease resistance. Their study (DOI: 10.1093/hr/uhae236), published in Horticulture Research on August 14, 2024, combined microbiome sequencing, machine learning, and bacterial isolation to investigate how host genotype and ecological niche shape microbial communities. Focusing on resistant and susceptible kiwifruit cultivars under real field conditions, the team uncovered key microbial players and demonstrated their ability to protect plants against Psa infection.
The researchers examined microbial communities across five plant compartments in four kiwifruit cultivars, including the resistant ‘Wanjin’ and susceptible ‘Donghong’. They found that disease-resistant varieties hosted richer and more stable microbiomes, especially in the root zone. In particular, the rhizosphere and root endosphere of ‘Wanjin’ contained higher abundances of beneficial bacteria such as Pseudomonas, Bacillus, Sphingomonas, and Streptomyces. When challenged with Psa, susceptible cultivars showed dramatic shifts in their microbiota, while ‘Wanjin’ maintained its microbial equilibrium.
Using machine learning, the team identified five bacterial families—Pseudomonadaceae, Sphingomonadaceae, Enterobacteriaceae, Erwiniaceae, and Microbacteriaceae—as key biomarkers of infection. From ‘Wanjin’, they isolated 420 bacterial strains, with over 13% showing strong antagonism toward Psa. Among these, Pseudomonas sp. R10 and Stenotrophomonas sp. R31 demonstrated powerful biocontrol effects. When used together, these strains reduced disease lesions significantly more than when applied individually, underscoring their synergistic potential. The results suggest that resistant cultivars not only tolerate disease better but actively shape their microbial allies for defense.
“This study offers compelling evidence that disease-resistant kiwifruit cultivars have a microbial advantage,” said Dr. Lixin Zhang, the study’s corresponding author. “By identifying core bacterial strains that are both genotype-associated and protective, we’re uncovering a biological blueprint for future disease management. These microbes are not just passengers—they’re active defenders. The goal is to move from chemical to biological control, leveraging what nature has already engineered within the plant.”
The findings lay the groundwork for microbiome-informed agriculture. In the future, growers may use microbial inoculants tailored to specific kiwifruit genotypes, reducing dependency on chemical treatments. The discovery of stable and protective bacteria like Pseudomonas and Stenotrophomonas opens new doors for biofertilizers and biopesticides that can be applied across growing regions. Moreover, these insights could inform breeding programs by selecting cultivars that naturally foster disease-fighting microbial communities. By aligning plant genetics with microbial ecology, the study provides a sustainable model for strengthening crop resilience through the power of beneficial microbes.
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References
DOI
10.1093/hr/uhae236
Original Source URL
https://doi.org/10.1093/hr/uhae236
Funding information
This study was supported by the National Key R&D Program of China (2022YFD1400200), the National Natural Science Foundation of China (32072378, 32302461), the Natural Science Key Research Project of Colleges and Universities in Anhui Province (2023AH050996), the Development Fund for Talent Personnel of Anhui Agricultural University (rc342216), and the Undergraduate Innovation and Entrepreneurship Training Program of Anhui province (S202310364172).
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.