Objectives

• To study the post-infectional changes in phenylpropanoid pathway in black pepper infested with Radopholus similis
• To characterize defence responses to R. similis in susceptible and resistant black pepper lines
• To investigate the inhibitory effects of phenylpropanoid pathway products on plant parasitic nematodes

Salient Achievements

• Changes in all the three phenyl propanoid pathway enzymes viz. PAL, C4H and COMT were monitored in a susceptible (Sreekara) and resistant (HP 39) black pepper varieties consequent to R. similis infection.
• Lignin content of the roots of the susceptible Sreekara and resistant HP-39 were estimated.
• Qualitative and quantitative assays were carried out for anthocayanidins, proanthocyanidins and their precursors, leucoanthocyanidins in root extracts of Sreekara and HP 39
• An EST based secretome analysis was carried out and the excretory-secretory (ES) proteins were identified. The presence of cellulose degrading enzymes was identified through some preliminary assays.
• Eight novel targets of R. similis, involved in invasion, parasitism, growth and survival were selected and modelled for further in silico analyses.
• Eighteen compounds out of 26 phytochemicals possessed antihelminthic (nematicidal) activity based on PASS prediction and were docked with the above eight nematode targets.(In silico bioassays)
• Eight promising compounds were tested for nematode mortality in four concentrations (200, 100, 50, 20 μg ml?1) under laboratory conditions(In vitro bioassays)
• The best two compounds, salicylic acid and ferulic acid were tested for suppression of R. similis in a pot study.(In planta bioassays)

Research Papers

1. Rosana OB, Krishna PB and Eapen SJ 2014. Virtual screening and in vitro assay to explore novel inhibitors from black pepper against potential targets of Radopholus similis. International Journal of Computer Applications 86(14): 35-43.
2. Sangeetha K., Rosana, O.B. and Eapen, S.J. 2012. EST secretome analysis of Radopholus similis nematode. Online J. Bioinformatics 13 (1):103-119.