_____________________________________________________________________________________________________ *Corresponding author: E-mail: manas.sahoo@icar.gov.in; International Research Journal of Pure & Applied Chemistry 21(12): 66-75, 2020; Article no.IRJPAC.60503 ISSN: 2231-3443, NLM ID: 101647669 Role of Ascorbate–Glutathione (AsA–GSH) Pathways in Phytophthora Leaf Blight Disease Resistance in Taro (Colocasia esculenta L. Schott) Yumnam Indrani Devi 1 , Madhumita Dasgupta 1 , Joydip Mandal 2 and Manas Ranjan Sahoo 1* 1 ICAR Research Complex for North Eastern Hill Region, Imphal, 795004, Manipur, India. 2 Visva Bharati, Sriniketan, 731236, West Bengal, India. Authors’ contributions This work was carried out in collaboration among all authors. Authors YID and MD carried out the experiment, data analyses, interpretation and writing of the draft manuscript. Authors JM and MRS Conceptualize the research, data analyses and write, review and edit. All the authors reviewed and approved the content of the manuscript. Article Information DOI: 10.9734/IRJPAC/2020/v21i1230240 Editor(s): (1) Dr. Farzaneh Mohamadpour, University of Sistan and Baluchestan, Iran. Reviewers: (1) Natalia Statsyuk, All-Russian Research Institute of Phytopathology, Russia. (2) Muhammad Mohsin, National Institute for Biotechnology and Genetic Engineering, Pakistan. Complete Peer review History: http://www.sdiarticle4.com/review-history/60503 Received 14 June 2020 Accepted 19 August 2020 Published 20 August 2020 ABSTRACT Taro (Colocasia esculenta L. Schott) is one of the important staple vegetable crops grown worldwide for its nutritious corms, leaves, and pseudostems. Taro invaded by leaf blight disease caused by Phytophthora colocasiae Racib. (Pc) resulted in 50% yield loss. On the other hand, inherent defense mechanisms of taro encounter the invaders to protect the plant from Pc invasion. The ascorbate–glutathione (AsA–GSH) pathways play an essential role in scavenging reactive oxygen species (ROS), a common phenomenon in plant–pathogen interaction. The present study focused on AsA–GSH regulations of thirty genotypes of taro under induced Pc infection. RCMC–5, among the tested taro genotypes, registered consistently higher induction of AsA, GSH, Ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), and dehydroascorbate reductase (DHAR) to encounter the Pc infection and overproduction of ROS. However, glutathione reductase (GR) was more prominent in DP–25, Jhankri, and TSL. AsA–GSH encounters the ROS overproduction, which was confirmed with lower H 2 O 2 (0.20 µM g –1 FW) and malondialdehyde (MDA) content (20.10 nM g –1 FW) in resistant genotypes (RCMC–5) subsequently resulted in Original Research Article