The syntaxin 31-induced gene, LESION SIMULATING DISEASE1 (LSD1), functions in <i>Glycine max</i> defense to the root parasite <i>Heterodera glycines</i>

<div><p>Experiments show the membrane fusion genes α soluble NSF attachment protein (α-SNAP) and syntaxin 31 (Gm-SYP38) contribute to the ability of <i>Glycine max</i> to defend itself from infection by the plant parasitic nematode <i>Heterodera glycines</i>. Accompanying their expression is the transcriptional activation of the defense genes ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) and NONEXPRESSOR OF PR1 (NPR1) that function in salicylic acid (SA) signaling. These results implicate the added involvement of the antiapoptotic, environmental response gene LESION SIMULATING DISEASE1 (LSD1) in defense. Roots engineered to overexpress the <i>G. max</i> defense genes Gm-α-SNAP, SYP38, EDS1, NPR1, BOTRYTIS INDUCED KINASE1 (BIK1) and xyloglucan endotransglycosylase/hydrolase (XTH) in the susceptible genotype <i>G. max</i>_{[Williams 82/PI 518671]} have induced Gm-LSD1 (Gm-LSD1–2) transcriptional activity. In reciprocal experiments, roots engineered to overexpress Gm-LSD1–2 in the susceptible genotype <i>G. max</i>_{[Williams 82/PI 518671]} have induced levels of SYP38, EDS1, NPR1, BIK1 and XTH, but not α-SNAP prior to infection. In tests examining the role of Gm-LSD1–2 in defense, its overexpression results in ∼52 to 68% reduction in nematode parasitism. In contrast, RNA interference (RNAi) of Gm-LSD1–2 in the resistant genotype <i>G. max</i>_{[Peking/PI 548402]} results in an 3.24–10.42 fold increased ability of <i>H. glycines</i> to parasitize. The results identify that Gm-LSD1–2 functions in the defense response of <i>G. max</i> to <i>H. glycines</i> parasitism. It is proposed that LSD1, as an antiapoptotic protein, may establish an environment whereby the protected, living plant cell could secrete materials in the vicinity of the parasitizing nematode to disarm it. After the targeted incapacitation of the nematode the parasitized cell succumbs to its targeted demise as the infected root region is becoming fortified.</p></div

Workflow for the Quantification of Soluble and Insoluble Carbohydrates in Soybean Seed

Soybean seed composition has a profound impact on its market value and commercial use as an important commodity. Increases in oil and protein content have been historically pursued by breeders and genetic engineers; consequently, rapid methods for their quantification are well established. The interest in complete carbohydrate profiles in mature seeds, on the other hand, has recently increased due to numerous attempts to redirect carbohydrates into oil and protein or to offer specialty seed with a specific sugar profile to meet animal nutritional requirements. In this work, a sequential protocol for quantifying reserve and structural carbohydrates in soybean seed was developed and validated. Through this procedure, the concentrations of soluble sugars, sugar alcohols, starch, hemicellulose, and crystalline cellulose can be determined in successive steps from the same starting material using colorimetric assays, LC&ndash;MS/MS, and GC&ndash;MS. The entire workflow was evaluated using internal standards to estimate the recovery efficiency. Finally, it was successfully applied to eight soybean genotypes harvested from two locations, and the resulting correlations of carbohydrate and oil or protein are presented. This methodology has the potential not only to guide soybean cultivar optimization processes but also to be expanded to other crops with only slight modifications

Mitogen activated protein kinase (MAPK)-regulated genes with predicted signal peptides function in the Glycine max defense response to the root pathogenic nematode Heterodera glycines.

Glycine max has 32 mitogen activated protein kinases (MAPKs), nine of them exhibiting defense functions (defense MAPKs) to the plant parasitic nematode Heterodera glycines. RNA seq analyses of transgenic G. max lines overexpressing (OE) each defense MAPK has led to the identification of 309 genes that are increased in their relative transcript abundance by all 9 defense MAPKs. Here, 71 of those genes are shown to also have measurable amounts of transcript in H. glycines-induced nurse cells (syncytia) produced in the root that are undergoing a defense response. The 71 genes have been grouped into 7 types, based on their expression profile. Among the 71 genes are 8 putatively-secreted proteins that include a galactose mutarotase-like protein, pollen Ole e 1 allergen and extensin protein, endomembrane protein 70 protein, O-glycosyl hydrolase 17 protein, glycosyl hydrolase 32 protein, FASCICLIN-like arabinogalactan protein 17 precursor, secreted peroxidase and a pathogenesis-related thaumatin protein. Functional transgenic analyses of all 8 of these candidate defense genes that employ their overexpression and RNA interference (RNAi) demonstrate they have a role in defense. Overexpression experiments that increase the relative transcript abundance of the candidate defense gene reduces the ability that the plant parasitic nematode Heterodera glycines has in completing its life cycle while, in contrast, RNAi of these genes leads to an increase in parasitism. The results provide a genomic analysis of the importance of MAPK signaling in relation to the secretion apparatus during the defense process defense in the G. max-H. glycines pathosystem and identify additional targets for future studies

The heterologous expression of a <i>Glycine max</i> homolog of NONEXPRESSOR OF PR1 (NPR1) and α-hydroxynitrile glucosidase suppresses parasitism by the root pathogen <i>Meloidogyne incognita</i> in <i>Gossypium hirsutum</i>

<p>Experiments in <i>Glycine max</i> (soybean) identified the expression of the salicylic acid signaling and defense gene NONEXPRESSOR OF PR1 (NPR1) in root cells (i.e., syncytium) parasitized by the plant parasitic nematode <i>Heterodera glycines</i> undergoing the process of resistance. Gm-NPR1-2 overexpression in <i>G. max</i> effectively suppresses parasitism by <i>H. glycines</i>. The heterologous expression of Gm-NPR1-2 in <i>Gossypium hirsutum</i> impairs the ability of the parasitic nematode <i>Meloidogyne incognita</i> to form root galls, egg sacs, eggs and second-stage juvenile (J2) nematodes. In related experiments, a <i>G. max</i> β-glycosidase (Gm-βg-4) related to <i>Lotus japonicus</i> secreted defense gene α-hydroxynitrile glucosidase LjBGD7 suppresses <i>M. incognita</i> parasitism. The results identify a cumulative negative effect that the transgenes have on <i>M. incognita</i> parasitism and demonstrate that the <i>G. max</i>–<i>H. glycines</i> pathosystem is a useful tool to identify defense genes that function in other agriculturally relevant plant species to plant parasitic nematodes with different strategies of parasitism.</p