search nucleotide sequence on clc main workbench

NB-LRR genes encode proteins that contain a C-terminal leucine rich repeat (LRR) domain, a highly conserved central nucleotide binding (NB) domain, and a variable N-terminal region. A recent report found that many genes were differentially expressed during switchgrass rust infection and that some of these genes belonged to the NB-LRR gene family, which is the largest family of plant disease resistance ( R) genes. In order to understand and improve disease resistance in switchgrass, the molecular mechanisms underlying tolerance to pathogen infection must be elucidated. The majority of switchgrass cultivars, including lowland and upland ecotypes, have been shown to be moderate to highly susceptible to this rust pathogen. The causal agent of switchgrass rust, Puccinia emaculata Schw., is widespread and has been reported in Tennessee, Arkansas, Virginia, and Mississippi. Airborne foliar fungal pathogens, like switchgrass rust, have potential to cause nationwide epidemics on switchgrass and have been shown to cause significant biomass yield losses. However, this practice is likely to reduce the genetic diversity in switchgrass that promotes disease resistance. Ĭurrently, industrial scale breeding programs of switchgrass have focused on optimizing biomass yield and improving feedstock quality in order to produce more biofuel. Lowland ecotypes also typically produce more biomass and are more tolerant to diseases than their upland counterparts however, upland ecotypes are considered to be more tolerant to drought and cold stresses. Lowland ecotypes are generally tetraploid in nature and grow in warm, moist, southern climates whereas upland ecotypes of switchgrass can be tetraploid, hexaploid, or octoploid and are usually found growing in the northern part of the United States into southern Canada. Two ecotypes of switchgrass, lowland and upland, have emerged that are adapted to different growth habitats. As a readily outcrossing species, native switchgrass germplasms have maintained a high level of genetic diversity over time. Switchgrass ( Panicum virgatum L.) is a North American prairie grass that can be used as a second generation bioenergy feedstock. These results also provide a foundation for future work aimed at elucidating the molecular mechanisms underlying disease resistance in this important bioenergy crop.

Our results provide useful insight into the molecular structure, distribution, and expression patterns of members of the NB-LRR gene family in switchgrass. RNA-sequencing data from field-grown cultivar ‘Summer’ plants indicated that the expression of some of these RGHs was developmentally regulated. RNA-sequencing analysis of leaf tissue from ‘Alamo’, a rust-resistant switchgrass cultivar, and ‘Dacotah’, a rust-susceptible switchgrass cultivar, identified 2634 high quality variants in the RGHs between the two cultivars. In addition, we identified 40 RGHs that potentially contain unique domains including major sperm protein domain, jacalin-like binding domain, calmodulin-like binding, and thioredoxin. In this study, we used a homology-based computational approach to identify 1011 potential NB-LRR resistance gene homologs (RGHs) in the switchgrass genome (v 1.1). Despite its importance as a prominent bioenergy crop, a genome-wide comprehensive analysis of NB-LRR disease resistance genes has yet to be performed in switchgrass. However, foliar fungal pathogens, like switchgrass rust, have the potential to significantly reduce switchgrass biomass yield. Switchgrass ( Panicum virgatum L.) is a warm-season perennial grass that can be used as a second generation bioenergy crop.

Search nucleotide sequence on clc main workbench