Homology-based characterization of the cis-regulatory elements modulate flavone induction of CYP321A1 in Helicoverpa armigera

Authors: DENG, ZHONGYUAN - Zhengzhou University; ZHANG, YUTING - Zhengzhou University; WANG, SHAN - Zhengzhou University; XIE, XINCHENG - Chinese Academy Of Agricultural Sciences; WANG, LIXIANG - Zhengzhou University; DING, QIAN - Zhengzhou University; Ni, Xinzhi; LI, XIANCHUN - University Of Arizona

Submitted to: Pesticide Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/11/2024
Publication Date: 8/17/2024
Citation: Deng, Z., Zhang, Y., Wang, S., Xie, X., Wang, L., Ding, Q., Ni, X., Li, X. 2024. Homology-based characterization of the cis-regulatory elements modulate flavone induction of CYP321A1 in Helicoverpa armigera. Pesticide Biochemistry and Physiology. 204: Article 106081. https://doi.org/10.1016/j.pestbp.2024.106081.
DOI: https://doi.org/10.1016/j.pestbp.2024.106081

Interpretive Summary: The corn earworm (also known as cotton bollworm) is an important pest occurs in the New World, and its close relative, also known as the old-world cotton bollworm, is widely distributed in Europe, Africa, Asia, and Oceania. Both pests cause significant damage on a wide range of crops, and the old-world bollworm has been found in Brazil in the new world. These two pests share morphological similarities in both adult and larval stages, and even mate successfully. Wild hybrids of the two pest species have been reported in Brazil. Understanding how these pests detoxify plant allelochemicals and insecticides (including transgenic Bt toxins) is important to design pest management strategies. It is still largely unknown by what means the insect pests utilize to upregulate their counter defense genes in response to plant allelochemicals. The current study demonstrated that the two closely-related species employed the same essential cis-acting element to upregulate their allelochemical-detoxification gene in response to flavone. Understanding of flexibility and adaptability for allelochemical response of old-world cotton bollworm could be utilized to improve management of these two closely related pests.

Technical Abstract: Xenobiotic response element (XRE) to flavone (Fla) was the cis-acting element mediated the induction of the allelochemical-metabolizing CYP321A1 gene from Helicoverpa zea. However, it was unknown whether the XRE-Fla element existed in other species. Recently we have identified and cloned the CYP321A1 gene with promoter region in a related species, Helicoverpa armigera. The coding sequence similarity of the two orthologous CYP321A1 genes was 97.27%, but their promoter sequence similarity was only 56.32%. Sequence alignment showed the XRE-Fla like element has three mutations in H. armigera compared with H. zea. Progressive 5’ deletions and internal mutation indicated that H. armigera XRE-Fla was the essential element of CYP321A1 gene in response to flavone. XRE-Fla mutations and EMSA analysis confirmed that the H. armigera XRE-Fla element bound to the corresponding transcription factors more strongly than H. zea XRE-Fla el. The findings indicate the XRE element mutations mainly contribute to the differences between the flavone-induced expressions of two CYP321A1 genes, which improve the flexibility and adaptability for allelochemical response of H. armigera.