Analysis of the Glycine max role of Syntaxin (SYP22) in resistance to Rotylenchulus reniformis

Abstract

Syntaxin proteins are involved in the process of membrane fusion. G. max syntaxin genes (Gm-SYP22-3, and GmSYP22-4) that were similar in amino acid composition have been found to contribute to the ability of Glycine max to defend itselffrom infection by the plant- parasitic nematode Rotylenchulus reniformis. The Gm-SYP22-3and Gm-SYP22-4 genes were expressed in root cells (syncytia) undergoing a resistant reaction while not being expressed in control cells. The Gm-SYP22-3 and Gm-SYP22-4 genes have been isolated from genetically engineered in G. max [Williams 82/PI518671], a genotype typically susceptible to R. reniformis parasitism. Genetically engineered plants in G. max [Williams 82/PI 518671] that lack the overexpression of Gm-SYP22-3 or Gm-SYP22-4 genes have also been produced to serve as a control. The transgenic Gm-SYP22-3 or Gm-SYP22-4 overexpression lines with their pRAP15 control have then been infected with R. reniformis. Infection was allowed to proceed for 30 days. At the end of the 30-day life span, R. reniformisstages were extracted from the soil and eggs from the roots, enumerated and compared to control plants. Plants overexpressing Gm-SYP22-3 or Gm-SYP22-4 had suppressed R. reniformis. In contrast, the gene expression levels of Gm-SYP22-3 and Gm-SYP22-4 were reduced in transgenic lines engineered for their RNA interference (RNAi) in G. max [Peking/PI 548402], a genotype normally resistant to R. reniformis. In comparison to genetically engineered control G. max [Peking/PI 548402] lines, RNAi of Gm-SYP22-3 or Gm-SYP22-4 resulted in an increase in parasitism in the normally R. reniformis resistant G. max [Peking/PI 548402].