Caspase-3 like Protein in Wheat- <i>Tilletia indica </i>Dual Culture System as Potential Biomarker for Host Resistance to Kamal Bunt

Abstract

Immuno-histochemical staining of dual co-cultured calli of <i>wheat-Tilletia indica </i>having resistant and susceptible

line using anti-mycelial and anti-teliospore polyclonal antibodies revealed the differential resistance response as

indicated by pathogen invasion, mycelial colonization, plasmolysis and immunolocalization of chlamydospore like

structures. The p⁵³and caspases, crucial proteins of cell death pathways were detected by immunological procedures

using heterologous immunoprobes in fungal colonized wheat calli. There was no difference in p⁵³expression in

resistant and susceptible lines at different days after inoculation (DAI) of <i>T. indica </i>on calli raised from mature

embryos. The expression of p⁵³started 14 DAI, increased steadily up to 21 DAI and became constant at 30 DAI

showing the saturation of expression level. Studies on the expression of caspases revealed the absence of caspase-I

like protein at different stages of growth. The caspase-3 like protein was induced at 3 DAI in both hosts and its

expression steadily increased at 14 DAI and reached a plateau at 21 DAI. A remarkable difference in the level of

expression of this protein between resistant and susceptible co-cultured calli was observed. Differential activation of

caspase-3 like protein was observed in 10 hosts and non-hosts. It was found to be correlated with the degree of

susceptibility and the expression of resistance at cellular level. Hence, it could be used as a potential biomarker for

identification of Karnal Bunt resistance sources.