Microbial Communities and Functions in the Rhizosphere of Disease-Resistant and Susceptible Camellia spp.

Abstract

Oil tea (Camellia spp.) is endemic to the hilly regions in the subtropics. Camellia yuhsienensis is resistant to diseases such as anthracnose and root rot, while Camellia oleifera is a high-yield species but susceptible to these diseases. We hypothesize that differences in the rhizosphere microbial communities and functions will elucidate the resistance mechanisms of these species. We used high-throughput sequencing over four seasons to characterize the rhizosphere microbiome of C. oleifera (Rhizo-Sus) and C. yuhsienensis (Rhizo-Res) and of the bulk soil control (BulkS). In Rhizo-Res, bacterial richness and diversity (Shannon index) in autumn and winter were both higher than that in Rhizo-Sus. In Rhizo-Res, fungal richness in autumn and winter and diversity in summer, autumn, and winter were higher than that in Rhizo-Sus. The seasonal variations in bacterial community structure were different, while that of fungal community structure were similar between Rhizo-Res and Rhizo-Sus. Gram-positive, facultatively anaerobic, and stress-tolerant bacteria were the dominant groups in Rhizo-Sus, while Gram-negative bacteria were the dominant group in Rhizo-Res. The significant differences in bacterial and fungal functions between Rhizo-Sus and Rhizo-Res were as follows: (1) in Rhizo-Sus, there were three bacterial and four fungal groups with plant growth promoting potentials, such as Brevibacterium epidermidis and Oidiodendron maius, and one bacterium and three fungi with pathogenic potentials, such as Gryllotalpicola sp. and Cyphellophora sessilis; (2) in Rhizo-Res, there were also three bacteria and four fungal groups with plant-growth-promoting potentials (e.g., Acinetobacter lwoffii and Cenococcum geophilum) but only one phytopathogen (Schizophyllum commune). In summary, the rhizosphere microbiome of disease-resistant C. yuhsienensis is characterized by a higher richness and diversity of microbial communities, more symbiotic fungal communities, and fewer pathogens compared to the rhizosphere of high-yield but disease-susceptible C. oleifera.

Genomic and genetic advances of oiltea-camellia (Camellia oleifera)

“…For example, species C. yuhsienensis is resistant to anthracnose, root rot diseases, and root knot nematode, but the high-yielding cultivar "Huashuo" of C.oleifera is susceptible to these diseases (Yang et al, 2004;Tan et al, 2011;Wei et al, 2013;Zhu et al, 2020;Chen et al, 2022b). Further study showed that the abundant and diverse microbial community in C. yuhsienensis rhizosphere may help to protect the host from pathogens (Li et al, 2021a) The plant growth and seed yield of oiltea-camellia are affected by anthracnose, a disease caused by Colletotrichum gloeosporioides. Anthracnose resistance is one of the most important traits for variety development of oiltea-camellia.…”

“…For example, species C. yuhsienensis is resistant to anthracnose, root rot diseases, and root knot nematode, but the high-yielding cultivar “Huashuo” of C.oleifera is susceptible to these diseases ( Yang et al., 2004 ; Tan et al., 2011 ; Wei et al., 2013 ; Zhu et al., 2020 ; Chen et al., 2022b ). Further study showed that the abundant and diverse microbial community in C. yuhsienensis rhizosphere may help to protect the host from pathogens ( Li et al., 2021a )…”

Linking plant functional genes to rhizosphere microbes: a review

“…Plant growth in variable environment is threatened by various biotic stresses such as pathogen, and gradually domesticate the corresponding resistance mechanisms (Bakker et al ., 2018 ; Chen et al ., 2020 ; Li et al ., 2021 ; Liu et al ., 2020 , 2021 ; Song et al ., 2021 ). When plants are invaded by pathogens, disease resistance genes will be activated, which in turn trigger plant‐specific molecular immune recognition systems (Teixeira et al ., 2019 ).…”

The mechanism of promoting rhizosphere nutrient turnover for arbuscular mycorrhizal fungi attributes to recruited functional bacterial assembly

“…The rhizosphere is a microhabitat in a narrow zone of soil surrounding plant roots with a high abundance of microorganisms (Kuzyakov & Razavi, 2019; Vetterlein et al, 2020). Microorganisms in the rhizosphere are directly influenced by host plants and are indirectly influenced by some environmental conditions (Li et al, 2021; Zhang et al, 2020). In the rhizosphere, plants release root exudates to promote bacterial community development (Caracciolo & Terenzi, 2021).…”