Secreted Expression of Cecropin B Gene Enhances Resistance to Xanthomonas
axonopodis pv. citri in Transgenic Citrus sinensis‘Tarocco’

ACTA HORTICULTURAE SINICA ›› 2014, Vol. 41 ›› Issue (3): 417-428.

Secreted Expression of Cecropin B Gene Enhances Resistance to Xanthomonas
axonopodis pv. citri in Transgenic Citrus sinensis‘Tarocco’

ZOU Xiu-ping*，PENG Ai-hong，LIU Qi-qi，HE Yong-rui，WANG Jun-zheng，XU Lan-zhen，LEI Tian-gang，
YAO Li-xiao，and CHEN Shan-chun*

Citrus Research Institute，Southwest University；Citrus Research Institute，Chinese Academy of Agricultural Sciences；
National Citrus Engineering Research Center；National Center for Citrus Varieties Improvement，Chongqing 400712，
China

Online:2014-03-25 Published:2014-03-25

Abstract

Abstract: A Citrus canker caused by Xanthomonas axonopodis pv. citri（Xac）is a very destructive
disease，which affects the citrus industry in most citrus-producing areas of the world. Here，we reported the
production of transgenic Tarocco blood orange（C. sinensis Osbeck）containing the synthetic antibacterial
peptide genes and the evaluation of transgenic plants for resistance to Xac. Two new Cecropin B（CB）
antibacterial peptide genes PR1aCB and AATCB with signal peptide（SP）sequence were synthesized by PCR. Transient RFP expression showed that fluorescence accumulation was observed predominantly in
intercellular space surrounding the onion epidermal cells transformed with PR1aCB︰rfp and AATCB︰rfp
genes compared with CB︰rfp without SP，indicating the SPs could direct protein secretion to the apoplast.
PR1aCB and AATCB gene cassettes driven by CaMV 35S were introduced into Tarocco blood orange by
Agrobacterium-mediated transformation. Integration of transgenes into citrus genome was confirmed by
GUS histochemical staining，PCR and Southern blot. Transcriptions of PR1aCB and AATCB genes were
detected by Real-time quantitative PCR in transgenic plants. Transgenic leaves were in vitro inoculated
with suspension of Xac. Compared to control（nontrangenic plants and pGN transgenic plants without
antibacterial gene），ten transgenic lines showed significant increase in resistance to citrus canker. The
levels of the resistance of the transgenic lines were equivalent to that of the highly resistant varieties：
Nanfeng Miju（C. succosa Hort. Ex Tan）and Calamondin（C. madurensis）.

Key words: Citrus, signal peptide, antibacterial peptide, citrus canker, genetic transformation, resistance

CLC Number:

S 666

ZOU Xiu-Ping, PENG Ai-Hong, LIU Qi-Qi, HE Yong-Rui, WANG Jun-Zheng, XU Lan-Zhen, LEI Tian-Gang, YAO Li-Xiao, CHEN Shan-Chun. Secreted Expression of Cecropin B Gene Enhances Resistance to Xanthomonas
axonopodis pv. citri in Transgenic Citrus sinensis‘Tarocco’[J]. ACTA HORTICULTURAE SINICA, 2014, 41(3): 417-428.

[1]	YE Zimao, SHEN Wanxia, LIU Mengyu, WANG Tong, ZHANG Xiaonan, YU Xin, LIU Xiaofeng, and ZHAO Xiaochun, . Effect of R2R3-MYB Transcription Factor CitMYB21 on Flavonoids Biosynthesis in Citrus [J]. Acta Horticulturae Sinica, 2023, 50(2): 250-264.
[2]	WANG Xiqing, JIA Yunhe, YAN Wen, FU Yongkai, YOU Haibo, LI Dongyan, and ZHAO Jingchao. A New Watermelon Cultivar‘Longsheng Jiali’with High Resistance to Fusarium Wilt [J]. Acta Horticulturae Sinica, 2023, 50(2): 455-456.
[3]	JIANG Jingdong, WEI Zhuangmin, WANG Nan, ZHU Chenqiao, YE Junli, XIE Zongzhou, DENG Xiuxin, CHAI Lijun. Exploitation and Identification of Tetraploid Resources of Hongkong Kumquat（Fortunella hindsii） [J]. Acta Horticulturae Sinica, 2023, 50(1): 27-35.
[4]	DU Yuling, YANG Fan, ZHAO Juan, LIU Shuqi, LONG Chaoan. Antifungal Mechanisms of Sodium New Houttuyfonate Against Penicillium digitatum [J]. Acta Horticulturae Sinica, 2023, 50(1): 145-152.
[5]	LI Zhenxi, PAN Ruixuan, XU Meirong, ZHENG Zheng, DENG Xiaoling. Development of Duplex Real-time PCR Assay of‘Candidatus Liberibacter asiatics’ [J]. Acta Horticulturae Sinica, 2023, 50(1): 188-196.
[6]	LI Zhiliang, LI Zhenxing, LI Tao, SUN Baojuan, LI Ying, XU Xiaowan, WANG Hengming, HENG Zhou, GONG Chao. A New Eggplant Cultivar‘Xinfeng 3’ [J]. Acta Horticulturae Sinica, 2023, 50(1): 227-228.
[7]	YANG Xingwang, WANG Haibo, WANG Yingying, WANG Xiaolong, WANG Zhiqiang, LIU Peipei, LIU Wanchun, and WANG Xiaodi. A New Mid-ripening and Cold Resistant Peach Cultivar‘Zhongnong Ganshuang’ [J]. Acta Horticulturae Sinica, 2022, 49(S2): 15-16.
[8]	YANG Xingwang, WANG Haibo, WANG Yingying, ZHANG Yican, WANG Baoliang, Liu Peipei, SHI Xiangbin, LIU Wanchun, and WANG Xiaodi. A New Mid-ripening Cold Resistant Peach Cultivar‘Zhongnong Baigan’ [J]. Acta Horticulturae Sinica, 2022, 49(S2): 17-18.
[9]	YANG Xingwang, LIU Fengzhi, WANG Haibo, WANG Yingying, WANG Zhiqiang, SHI Xiangbin, JI Xiaohao, LIU Wanchun, and WANG Xiaodi. A New Mid-ripening Cold Resistant Peach Cultivar‘Zhongnong Hanshuimi’ [J]. Acta Horticulturae Sinica, 2022, 49(S2): 19-20.
[10]	YANG Xingwang, LIU Fengzhi, WANG Haibo, WANG Yingying, ZHANG Yican, LI Peng, WANG Xiaolong, LIU Wanchun, and WANG Xiaodi. A New Late-ripening Cold Resistant Peach Cultivar‘Zhongnong Qiuxiang’ [J]. Acta Horticulturae Sinica, 2022, 49(S2): 21-22.
[11]	QI Yongjie, GAO Zhenghui, MA Na, WANG Qingming, KE Fanjun, CHEN Qian, and XU Yiliu, . A New Yellow Flesh and Resistant to Canker Disease Kiwifruit Cultivar ‘Wannong Jinguo’ [J]. Acta Horticulturae Sinica, 2022, 49(S2): 49-50.
[12]	YU Yangjun, WANG Weihong, SU Tongbing, ZHANG Fenglan, ZHANG Deshuang, ZHAO Xiuyun, YU Shuancang, LI Peirong, XIN Xiaoyun, and WANG Jiao. A New Chinese Cabbage Cultivar‘Jingchun CR3’with Clubroot Resistance and Bolting Tolerance [J]. Acta Horticulturae Sinica, 2022, 49(S2): 87-88.
[13]	WANG Lili, WANG Xin, WU Haidong, WEN Qiang, and Yang Xiaofei. A New Chinese Cabbage Cultivar‘Liaobai 28’with Resistance to Clubroot Disease [J]. Acta Horticulturae Sinica, 2022, 49(S2): 89-90.
[14]	LIU Zhiyuan, XU Zhaosheng, ZHANG Helong, and QIAN Wei. A New Oversummer Spinach Cultivar‘Shubo 16’ [J]. Acta Horticulturae Sinica, 2022, 49(S2): 95-96.
[15]	HUANG Shuping, TAN Jie, Chen Xia, ZHANG Hongyuan, LI Ye, WANG Benqi, CHEN Hao, WU Xuexia, and ZHANG Min, . A New Eggplant Cultivar‘Eqie 6’ [J]. Acta Horticulturae Sinica, 2022, 49(S2): 101-102.