Identification of High Tolerance to Jujube Witches’ Broom in Indian Jujube (<i>Ziziphus mauritiana</i> Lam.) and Mining Differentially Expressed Genes Related to the Tolerance through Transcriptome Analysis
Yaru Xu,
Chao Wang,
Decang Kong,
Ming Cao,
Qiong Zhang,
Muhammad Tahir,
Ying Yang,
Shuang Yang,
Wenhao Bo,
Xiaoming Pang
Affiliations
Yaru Xu
State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
Chao Wang
State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
Decang Kong
National Foundation for Improved Cultivar of Chinese Jujube, Cangzhou 061000, China
Ming Cao
National Foundation for Improved Cultivar of Chinese Jujube, Cangzhou 061000, China
Qiong Zhang
Shandong Institute of Pomology, Taian 271000, China
Muhammad Tahir
State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
Ying Yang
State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
Shuang Yang
State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
Wenhao Bo
State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
Xiaoming Pang
State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
The jujube witches’ broom (JWB) disease is a severe threat to jujube trees, with only a few cultivars being genuinely tolerant or resistant to phytoplasma. The defense mechanism of jujube trees against phytoplasma is still unclear. In this study, we aimed to investigate the tolerance mechanism of Indian jujube ‘Cuimi’ to JWB and identify the key genes that contribute to JWB high tolerance. Based on the symptoms and phytoplasma concentrations after infection, we confirmed the high tolerance of ‘Cuimi’ to JWB. Comparative transcriptome analysis was subsequently performed between ‘Cuimi’ and ‘Huping’, a susceptible cultivar of Chinese jujube. Unique gene ontology (GO) terms were identified in ‘Cuimi’, such as protein ubiquitination, cell wall biogenesis, cell surface receptor signaling pathway, oxylipin biosynthetic process, and transcription factor activity. These terms may relate to the normal development and growth of ‘Cuimi’ under phytoplasma infection. We identified 194 differential expressed genes related to JWB high tolerance, involved in various processes, such as reactive oxygen species (ROS), Ca2+ sensors, protein kinases, transcription factors (TFs), lignin, and hormones. Calmodulin-like (CML) genes were significantly down-regulated in infected ‘Cuimi’. We speculated that the CML gene may act as a negative regulatory factor related to JWB high tolerance. Additionally, the cinnamoyl-CoA reductase-like SNL6 gene was significantly up-regulated in infected ‘Cuimi’, which may cause lignin deposition, limit the growth of phytoplasma, and mediate immune response of ‘Cuimi’ to phytoplasma. Overall, this study provides insights into the contribution of key genes to the high tolerance of JWB in Indian jujube ‘Cuimi’.
