Comparative transcriptomic profiling of susceptible and resistant cultivars of pigeonpea demonstrates early molecular responses during Fusarium udum infection

Abstract

Vascular wilt caused by Fusarium udum Butler is the most important disease of pigeonpea throughout the world. F. udum isolate MTCC 2204 (M1) inoculated pigeonpea plants of susceptible (ICP 2376) and resistant (ICP 8863) cultivars were taken at invasion stage of pathogenesis process for transcriptomic profiling to understand defense signaling reactions that interplay at early stage of this plant–pathogen encounter. Differential transcriptomic profiles were generated through cDNA-AFLP from M1 inoculated resistant and susceptible pigeonpea root tissues. Twenty five percent of transcript derived fragments (TDFs) were found to be pathogen induced. Among them 73 TDFs were re-amplified and sequenced. Homology search of the TDFs in available databases and thorough study of scientific literature identified several pathways, which could play crucial role in defense responses of the F. udum inoculated resistant plants. Some of the defense responsive pathways identified to be active during this interaction are, jasmonic acid and salicylic acid mediated defense responses, cell wall remodeling, vascular development and pattering, abscisic acid mediated responses, effector triggered immunity, and reactive oxygen species mediated signaling. This study identified important wilt responsive regulatory pathways in pigeonpea which will be helpful for further exploration of these resistant components for pigeonpea improvement.

Differential transcript expression profiles of susceptible and resistant pigeonpea cultivars at an early time point during Fusarium udum infection

“…Seeds of wilt-susceptible ICP 2376 and wilt-resistant ICP 8863 cultivars were collected from International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana, India. After surface sterilization of seeds, susceptible and resistant seedlings were grown in soilrite at 22–25°C, 35%–40% humidity, and a 16-h photoperiod ( Purohit et al, 2021 ).…”

“…On the basis of our previous report, it was found that at the early stage of F. udum infection, maximum disease-responsive pathways were altered in pigeonpea ( Purohit et al, 2021 ). Accordingly, the present study was designed to perform NGS-based comparative transcriptomic profiling of F. udum -induced transcripts at the early (36 HPI) infection stage in pigeonpea through an RNA-seq technique to accomplish a thorough understanding of the differentially expressed genes.…”

“…Invasion of all nine isolates of F. udum in healthy pigeonpea root was identified at 24–36 hours post-inoculation (HPI), determined through anatomical, morphological, and biochemical studies of the infected root ( Purohit et al, 2017 ). At 36 HPI (i.e., invasion stage), cDNA-AFLP-mediated comparative transcriptomics study on F. udum inoculated root of wilt-susceptible (ICP 2376) and wilt-resistant pigeonpea cultivars (ICP 8863) along with their mock inoculated controls were performed by Purohit et al (2021) . Among all differentially expressed transcript-derived fragments (TDFs), many were identified to be involved in disease resistance or tolerance mechanisms.…”

“…The identified important defense responsive pathways were pathogen-triggered immunity, effector-triggered immunity, reactive oxygen species-mediated signaling, salicylic acid- and jasmonic acid-mediated defense responses, cell wall remodeling, vascular development and pattering, and abscisic acid-mediated responses. These pathways were found to be activated during pathogen attacks and played crucial roles in defense responses ( Purohit et al, 2021 ).…”

Identification of Crucial Genes and Regulatory Pathways in Alfalfa against Fusarium Root Rot

“…Fusarium spp. is a soil-borne pathogen that mainly overwinters in the form of mycelia and spores in diseased residues, infected seeds, and soil [17]. Fusarium spp.…”