Attenuation of ethylene signaling increases cotton resistance to a defoliating strain of Verticillium dahliae

Authors: WANG, TIANYI - Huazhong Agricultural University; SHABAN, MUHAMMAD - Huazhong Agricultural University; SHI, JUNHUI - Huazhong Agricultural University; WANG, WEIRAN - Chinese Academy Of Agricultural Sciences; LIU, SHIMIN - Huazhong Agricultural University; NIE, XINHUI - Shihezi University; YU, YU - Chinese Academy Of Agricultural Sciences; KONG, JIE - Chinese Academy Of Agricultural Sciences; Klosterman, Steven; ZHANG, XIANLONG - Huazhong Agricultural University; AIERXI, ALIFU - Xinjiang Academy Of Agricultural And Reclamation Science; ZHU, LONGFU - Huazhong Agricultural University

Submitted to: The Crop Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/2022
Publication Date: 6/25/2022
Citation: Wang, T., Shaban, M., Shi, J., Wang, W., Liu, S., Nie, X., Yu, Y., Kong, J., Klosterman, S.J., Zhang, X., Aierxi, A., Zhu, L. 2022. Attenuation of ethylene signaling increases cotton resistance to a defoliating strain of Verticillium dahliae. The Crop Journal. 11(1):89-98. https://doi.org/10.1016/j.cj.2022.05.008.
DOI: https://doi.org/10.1016/j.cj.2022.05.008

Interpretive Summary: Verticillium dahliae is a fungus that causes Verticillium wilt disease on many economically important crops, including cotton. Recent studies have revealed increased numbers of V. dahliae strains identified in infected plants are of the aggressive type associated with leaf defoliation in cotton. The plant hormone ethylene is commonly associated with diverse plant processes such as ripening, leaf senescence, and defoliation. This study examined the production of the plant hormone ethylene in cotton in response to the aggressive defoliating strain of V. dahliae and a non-defoliating strain of V. dahliae. Plants inoculated with the defoliating strain had higher levels of ethylene than plants inoculated with the non-defoliating strain. Some plant genes involved in ethylene signaling were up-regulated (i.e., exhibited increased expression) more strongly in response to the defoliating strain versus in response to the non-defoliating strain. The study of mechanisms which cause leaf defoliation provides insights on alternative control approaches for Verticillium wilt of cotton and other crops such as olive and okra where defoliation occurs.

Technical Abstract: The severity of Verticillium wilt on cotton caused by defoliating strains of Verticillium dahliae has gradually increased and threatens production worldwide. Identification of the molecular components of leaf defoliation may increase cotton tolerance to V. dahliae. Ethylene, a major player in plant physiological processes, is often associated with senescence and defoliation of plants. We investigated the cotton–V. dahliae interaction with a focus on the role of ethylene in defoliation and defense against V. dahliae. Cotton plants inoculated with V. dahliae isolate V991, a defoliating strain, accumulated more ethylene and showed increased disease symptoms than those inoculated with a non-defoliating strain. In cotton with a transiently silenced ethylene synthesis gene (GhACOs) and signaling gene (GhEINs) during cotton–V. dahliae interaction, ethylene produced was derived from cotton and more ethylene increased cotton susceptibility and defoliation rate. Overexpression of AtCTR1, a negative regulator in ethylene signaling, in cotton reduced sensitivity to ethylene and increased plant resistance to V. dahliae. Collectively, the results indicated precise regulation of ethylene synthesis or signaling pathways improve cotton resistant to Verticillium wilt.