Testing and modelling the potential of three diploid plants in Poaceae as a new pathosystem to investigate the interactions between cereal hosts and cereal cyst nematode (Heterodera avenae)

Abstract

Cereal cyst nematode (CCN), Heterodera avenae, is one of the most important pathogens of wheat worldwide, and causes significant yield losses. Research on CCN-wheat interactions is hampered by the lack of an effective model pathosystem. This study investigated the potential of the model cereal Brachypodium distachyon (Bd21-3) and diploid wheat 2A (G1812) and 2D (AL8/78) as model hosts for CCN. Nematode infection analysis showed that although some CCN penetrated Bd21-3 roots, these nematodes failed to develop to the later developmental stages or form cysts, indicating B. distachyon is not a host for CCN. A strong burst of reactive oxygen species (ROS) within Bd21-3 roots infected with CCN was induced 3 days after infection and the expression of seven ROS-producing genes was significantly increased. In contrast, CCN completed its life cycle in both diploid wheat 2A and 2D, and formed normal syncytia in these hosts. Although CCN developmental processes within both diploid wheat 2A and 2D were very similar to those in the susceptible control, the number of cysts formed on diploid wheat 2D was less than those formed on diploid wheat 2A and the susceptible control, indicating that diploid wheat 2A was a more suitable host for CCN than 2D. This is the first report of a potential new pathosystem for CCN-host interactions using diploid wheat.

Host status of Brachypodium distachyon to the cereal cyst nematode

“…In this research, we evaluated the sensitivity distachyon is a host of CCN though not very susceptible. It was reported that Bd21-3 was not a host for CCN, as nematodes penetrated roots but failed to develop to the later developmental stages or form cysts (Kong et al 2016). While in this research, Bd21-3 formed 0.2±0.4 (0-1) cysts/plant, which was not consistent with previous report.…”

“…While in this research, Bd21-3 formed 0.2±0.4 (0-1) cysts/plant, which was not consistent with previous report. These two contrary results might be due to different CCN populations inoculated, that is, we inoculated DX CCN while Kong et al (2016) used population they maintained in a greenhouse by themselves.…”

Targeted and Untargeted Metabolomic Analyses Reveal Organ Specificity of Specialized Metabolites in the Model Grass Brachypodium distachyon

“…A breakthrough point in Brachypodium research was the genome sequencing of accession Bd21 [3], which contributed to several genetic and genomic resources including Phytozome [4] and Gramene [5] and gave rise to initiatives like BrachyPan (Brachypodium pan-genome) [6]. Consequently, Brachypodium became an object of intense research in many fields serving in understanding interaction of grasses with viruses [7], bacteria [8], fungi [9] and invertebrates [10] as well as their responses to abiotic stresses [11].…”

Golden Promise barley (Hordeum vulgare) is a suitable candidate model host for investigation interaction with Heterodera avenae

“…The wheat cultivar, named Wenmai 19 (Triticum aestivum) was proven to be susceptible to CCN, and H. avenae also infects and develops in Triticum urartu and Aegilops tauschii but not in Brachypodium distachyon (Kong et al 2016). The Hordeum vulgare cultivar Skiff showed susceptibility, while the cultivar Chebec was resistant (Aditya et al 2015).…”