Syntaxin 31 functions in Glycine max resistance to the plant parasitic nematode Heterodera glycines

Abstract

A Glycine max syntaxin 31 homolog (Gm-SYP38) was identified as being expressed in nematode-induced feeding structures known as syncytia undergoing an incompatible interaction with the plant parasitic nematode Heterodera glycines. The observed Gm-SYP38 expression was consistent with prior gene expression analyses that identified the alpha soluble NSF attachment protein (Gm-α-SNAP) resistance gene because homologs of these genes physically interact and function together in other genetic systems. Syntaxin 31 is a protein that resides on the cis face of the Golgi apparatus and binds α-SNAP-like proteins, but has no known role in resistance. Experiments presented here show Gm-α-SNAP overexpression induces Gm-SYP38 transcription. Overexpression of Gm-SYP38 rescues G. max [Williams 82/PI 518671], genetically rhg1 (-/-), by suppressing H. glycines parasitism. In contrast, Gm-SYP38 RNAi in the rhg1 (+/+) genotype G. max [Peking/PI 548402] increases susceptibility. Gm-α-SNAP and Gm-SYP38 overexpression induce the transcriptional activity of the cytoplasmic receptor-like kinase BOTRYTIS INDUCED KINASE 1 (Gm-BIK1-6) which is a family of defense proteins known to anchor to membranes through a 5' MGXXXS/T(R) N-myristoylation sequence. Gm-BIK1-6 had been identified previously by RNA-seq experiments as expressed in syncytia undergoing an incompatible reaction. Gm-BIK1-6 overexpression rescues the resistant phenotype. In contrast, Gm-BIK1-6 RNAi increases parasitism. The analysis demonstrates a role for syntaxin 31-like genes in resistance that until now was not known.

A plant transformation system designed for high throughput genomics inGossypium hirsutumto study root–organism interactions

“…The pRAP15 vector was originally developed for Agrobacterium rhizogenes-mediated root genetic engineering experiments in G. max (Matsye et al 2012;Matthews et al 2013Matthews et al , 2014Pant, Matsye, et al 2014;. The sequence of the pRAP15 vector used in the study was determined prior to the analysis (Eurofins MWG Operon, Huntsville, Alabama; Matsye et al 2012).…”

“…The expression of the cassette is driven by the figwort mosaic virus sub-genomic transcript (FMV-sgt) promoter (Bhattacharyya et al 2002). By using FMV-sgt as the promoter, the cassette is designed to drive the overexpression of full length genes and maintain high expression throughout plant-organism interactions (Klink et al 2008(Klink et al , 2009Matsye et al 2012;Pant, Matsye, et al 2014;). The pRAP15 vector was engineered to have the tetracycline resistance gene for bacterial selection, found to be important for work with A. rhizogenes (Klink et al 2008).…”

“…The G. hirsutum root transformation method presented here was performed according to our published procedures using the pRAP15 vector with modifications (Matsye et al 2012;Pant, Matsye, et al 2014;. The PCR primers used in the cloning experiments are provided in Table 1.…”

“…The system is shown to be capable of expressing an eGFP reporter and a Glycine max NONEXPRESSOR OF PATHOGENESIS RELATED 1 (Gm-NPR1) transgene (Pant, Matsye, et al 2014). A comparative analysis, including the efficiency of transformation in G. hirsutum, is presented showing the rate by which roots useful for experimentation are generated.…”

“…A comparative analysis, including the efficiency of transformation in G. hirsutum, is presented showing the rate by which roots useful for experimentation are generated. The system presented here differs from other hairy root-based systems developed in G. hirsutum in that, by using eGFP as a reporter system, the experiments can be performed under nonaxenic conditions throughout the study (Triplett et al 2008;Kim et al 2011;Matsye et al 2012;Pant, Matsye, et al 2014;. Furthermore, the platform is Gateway® compatible which simplifies the isolation and study of hundreds to thousands of genes identified in bioinformatics analyses (Matsye et al 2012;Matthews et al 2013;Pant, Matsye, et al 2014;Klink & Thibaudeau 2014).…”