|Klink, Vincent -|
|Hosseini, Parsa -|
|Matsye, Prachi -|
|Alkharouf, Nadmi -|
Submitted to: Plant Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 13, 2010
Publication Date: December 14, 2012
Citation: Klink, V.P., Hosseini, P., Matsye, P.D., Alkharouf, N.W., Matthews, B.F. 2012. Differences in gene expression amplitude overlie a conserved transcriptomic program occurring between the rapid and potent localized resistant reaction at the syncytium of the Glycine max genotype Peking (PI 548402). Plant Molecular Biology. 75:141-165. Interpretive Summary: Soybean cyst nematode is the major pest of soybean in the USA and it causes an estimated one billion dollars in losses each year. There are two natural sources of soybean that provide resistance to some populations of this nematode. One source of resistance elicits a rapid response against certain populations while the second source of resistance reacts more slowly to the same populations. We compared the pattern of gene expression of over 30,000 genes between these two sources of resistance and we identified differences in the expression of specific genes that may be important to resistance. This information is important to scientists developing new sources of resistance through genetic engineering and plant breeding techniques.
Technical Abstract: Glycine max L. Merr. (soybean) resistance to Heterodera glycines Ichinohe occurs at the site of infection, a nurse cell known as the syncytium. Resistance is classified into two cytologically-defined responses, the G. max[Peking]- and G. max[PI 88788]-types. Each type represents a cohort of G. max genotypes. Resistance in G. max[Peking] occurs by a potent and rapid localized response, affecting parasitic second stage juveniles (p-J2). In contrast, resistance occurs by a potent but more prolonged reaction in the genotype G. max[PI 88788] that affects nematode development at the J3 and J4 stages. Microarray analyses comparing these cytologically and developmentally distinct resistant reactions reveal differences in gene expression in pericycle and surrounding cells even before infection. The differences include higher relative levels of the differentially expressed in response to arachidonic acid 1 gene (DEA1 [Gm-DEA1]) (+224.19-fold) and a protease inhibitor (+68.28-fold) in G. max[Peking/PI 548402] as compared to G. max[PI 88788]. Gene pathway analyses compare the two genotypes (1) before, (2) at various times during, (3) constitutively throughout the resistant reaction and (4) at all time points prior to and during the resistant reaction. The amplified levels of transcriptional activity of defense genes may explain the rapid and potent reaction in G. max[Peking/PI 548402] as compared to G. max[PI 88788]. In contrast, the shared differential expression levels of genes in G. max[Peking/PI 548402] and G. max[PI 88788] may indicate a conserved genomic program underlying the G. max resistance on which the genotype-specific gene expression programs are built.