An international research group led by Prof. Haiping Wang at IVF-CAAS sheds light on the molecular mechanisms of Ca2+ sensor BraCBL1.2 in clubroot resistance in Chinese cabbage

Chinese cabbage (Brassica rapa L. ssp pekinensis) is one of the most important leafy vegetables cultivated worldwide. Clubroot disease caused by a soil-borne obligate biotrophic Plasmodiophora brassicae (Pb) severely affects the yield and quality of cruciferous crops, especially Chinese Cabbage. BraCRa, as one of the earliest cloned clubroot resistance gene, confers race-specific resistance to Pb. As TNL-type resistance (R) gene in plant, BraCRa is supposed to induce Ca²⁺ influx with the help of Ca²⁺ permeable channel. However, the identity of downstream Ca²⁺ sensors and decoders of BraCRa are still elusive.

A manuscript entitled “A Ca²⁺ sensor BraCBL1.2 involves in BraCRa-mediated clubroot resistance in Chinese cabbage” published as article in “Horticulture Research”.

The aim of this study is to identify the specific isolates of Pb protested by BraCRa and identify the downstream Ca²⁺ sensor of CRa. In this study, the spatial and temporal expression pattern of BraCRa were investigated by histochemical staining in Arabidopsis. CRa is primarily expressed in root hair cells and its protein is localized in cytoplasm and plasma membrane. Moreover, we screened multiple virulent and avirulent Pb isolates of Chinese Cabbage line CR 3-2, which harbors BraCRa. BraCRa exhibits board-spectrum Pb resistance in B. rapa. Through transcriptomic analysis, we identified a plasma membrane-localized Ca²⁺ sensor BraCBL1.2 functions downstream of BraCRa upon Pb infection. Additionally, BraCBL1.2 exhibited similar spatial and temporal expression pattern with BraCRa. Furthermore, we developed a tobacco-based HR assay to prove the involvement of BraCBL1.2 in BraCRa-mediated ETI response. Finally, we verified that overexpression of BraCBL1.2 enhanced clubroot resistance in Arabidopsis. Therefore, our study firstly demonstrated that BraCRa exerts clubroot resistance in root hair cell of cruciferous plants and identified BraCBL1.2 as one of the downstream Ca²⁺ sensor of BraCRa during Pb infection.

Collectively, this study identified the involvement of a Ca²⁺ sensor in BraCRa-mediated clubroot resistance in Chinese cabbage, providing a theoretical basis for further research on the resistance of Chinese cabbage to P. brassicae.

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References

Authors

Yinglan Piao^1†, Shizhen Li^3†, Yiduo Chen⁴, Sisi Zhao¹, Zhongyun piao^2*, Haiping Wang^1*

Affiliations

¹State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China

²College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China

³State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China

⁴Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität, Münster, Germany

About Prof. Haiping Wang & Prof. Zhongyun Piao

Prof. Haiping Wang

Key areas of interest include garlic,  ginger, radish and cucumber genetics and development of genomic tools, genetic improvement of garlic disease resistance, garlic diversity and origins, and of human nutritional quality and flavor of both garlic and ginger.

Prof. Zhongyun Piao

Research on germplasm resource innovation, disease resistance mechanisms, cloning and functional analysis of important genes, and molecular breeding of Brassica crops such as Chinese cabbage and rapeseed.