Functional analysis of MeCIPK23 and MeCBL1/9 in cassava defense response against Xanthomonas axonopodis pv. manihotis
MeCIPK23 interacts with MeCBL1/9, and they confer improved defense response, providing potential genes for further genetic breeding in cassava.
Cassava (Manihot esculenta) is an important food crop in tropical area, but its production is largely affected by cassava bacterial blight. However, the information of defense-related genes in cassava is very limited. Calcium ions play essential roles in plant development and stress signaling pathways. Calcineurin B-like proteins (CBLs) and CBL-interacting protein kinases (CIPKs) are crucial components of calcium signals. In this study, systematic expression profile of 25MeCIPKs in response to Xanthomonas axonopodis pv. manihotis (Xam) infection was examined, by which seven candidate MeCIPKs were chosen for functional investigation. Through transient expression in Nicotiana benthamiana leaves, we found that six MeCIPKs (MeCIPK5, MeCIPK8, MeCIPK12, MeCIPK22, MeCIPK23 and MeCIPK24) conferred improved defense response, via regulating the transcripts of several defense-related genes. Notably, we found that MeCIPK23 interacted with MeCBL1 and MeCBL9, and overexpression of these genes conferred improved defense response. On the contrary, virus-induced gene silencing of either MeCIPK23 or MeCBL1/9 or both genes resulted in disease sensitive in cassava. To our knowledge, this is the first study identifying MeCIPK23 as well as MeCBL1 and MeCBL9 that confer enhanced defense response against Xam.
KeywordsCalcium CBL-interacting protein kinase (CIPK) Cassava (Manihot esculenta) Cassava bacterial blight Xanthomonas axonopodis pv. manihotis (Xam)
Biomolecular fluorescence complementation
Calcineurin B-like protein
CBL-interacting protein kinase
Calcium-dependent protein kinase
Day post infiltration
Green fluorescent protein
Microbe/pathogen-associated molecular patterns
Nonexpresser of PR genes 1
2C-type protein phosphatase
Respiratory burst oxidase homologues
Reactive oxygen species
Virus-induced gene silencing
Xanthomonas axonopodis pv. manihotis
We thank Dr. Chris R. Somerville, Dr. Jie Zhou, Dr. Yanru Hu, and Dr. Jiang Tian for sharing their vector plasmids. This research was supported by the National Natural Science Foundation of China (No. 31760067), the startup funding and the scientific research foundation of Hainan University (No. kyqd1531) to Haitao Shi.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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