Effect of Pesticides on Salicylic Acid Binding Protein 2 (SABP2) and Plant Defense

• Main Author: Yuh, Joannes Petrus
• Format: Others
• Published: Digital Commons @ East Tennessee State University 2011
• Subjects: Systemic Acquired Resistance; Salicylic Acid Binding Protein 2; Salicylic Acid; Pathogenesis Related Protein; Malathion; Parathion; Plant Defense; Biology; Life Sciences
• Online Access: https://dc.etsu.edu/etd/2259; https://dc.etsu.edu/cgi/viewcontent.cgi?article=3611&context=etd

Tobacco SABP2 has been shown to display high affinity for salicylic acid (SA) and methylsalicylate (MeSA) and plays an important role in SAR signal development. Using biochemical approach, SABP2 has been shown to demonstrate strong esterase activity in converting MeSA to SA. Recent study shows that tetra fluoroacetophenone, a synthetic analog of SA, competitively inhibits SABP2 esterase activity as well as suppresses SAR signal development in tobacco mosaic virus (TMV)-infected tobacco plants. Not much has been studied on the effect of pesticides on plant defenses. Because both AChE and SABP2 are esterase-like proteins belonging to α/β hydroxylase superfamily, we hypothesize that pesticides may inhibit the MeSA esterase activity of SABP2 and block SAR development. Biochemical and molecular biology techniques were used to test this hypothesis. SAR in tobacco-TMV plant-pathogen system is measured by significant decrease in TMV-induced lesion sizes in secondarily inoculated distal leaves.