Project description:Sets of seven 2-week old potato plants carrying the nematode resistance gene H1, grown from tuber ‘chits’ in sandy loam at a constant temperature of 20 ºC and a light cycle of 16 hour light/8 hour dark, were each inoculated in the roots evenly with 2000 juveniles of the virulent potato cyst nematode Globodera pallida, or with the avirulent G. rostochiensis pathotype Ro1, or with water. Plants were manually watered throughout the duration of the experiment. 5, 17 and 33 days after inoculation, the roots were carefully washed and root tissue samples were individually flash-frozen in liquid nitrogen and stored at –80 ºC. Total RNA isolations were performed using the Qiagen RNeasy kit. All samples were treated with DNase. The experiment was replicated twice. Keywords: Direct comparison
Project description:The potato cyst nematodes (PCN), Globodera pallida and Globodera rostochiensis, are important parasites of potato. PCN have complex, biotrophic interactions with their hosts that involve gene expression changes in both the nematode and the host plant. The aim of this study is to determine key genes that are differentially expressed in Globodera pallida life cycle stages and during the initiation of the feeding site in susceptible or partially resistant potato genotypes. For this purpose, two microarray experiments were designed: i) a comparison of eggs, infective second stage juveniles (J2) and sedentary parasitic stage J2s (SJ2); ii) a comparison of SJ2 at eight days after inoculation (DAI) in the susceptible cultivar (Desiree) and two partially resistant lines. The data set in this submission came from experiment (I). The results show differential expression of G. pallida genes during the stages studied, including previously characterized effectors. Also, a large number of genes changed their expression between the SJ2 in the susceptible cultivar compared to those infecting partially resistant lines; the number of genes with modified expression were smaller when two partially resistant lines were compared. Additionally, a histopathological study was performed at several time points (7, 14 and 30 DAI) showing the similarities between both partially resistant lines with a delay and degeneration in the formation of the syncytia in comparison to the susceptible cultivar. Females at 30 DAI in partially resistant lines showed a delay in their development in comparison to the susceptible cultivar.
Project description:The potato cyst nematodes (PCN), Globodera pallida and Globodera rostochiensis, are important parasites of potato. PCN have complex, biotrophic interactions with their hosts that involve gene expression changes in both the nematode and the host plant. The aim of this study is to determine key genes that are differentially expressed in Globodera pallida life cycle stages and during the initiation of the feeding site in susceptible or partially resistant potato genotypes. For this purpose, two microarray experiments were designed: i) a comparison of eggs, infective second stage juveniles (J2) and sedentary parasitic stage J2s (SJ2); ii) a comparison of SJ2 at eight days after inoculation (DAI) in the susceptible cultivar (Desiree) and two partially resistant lines. The data set in this submission came from experiment (ii). (Experiment (I) has also been deposited in ArrayExpress under accession E-MTAB-999). The results show differential expression of G. pallida genes during the stages studied, including previously characterized effectors. Also, a large number of genes changed their expression between the SJ2 in the susceptible cultivar compared to those infecting partially resistant lines; the number of genes with modified expression were smaller when two partially resistant lines were compared. Additionally, a histopathological study was performed at several time points (7, 14 and 30 DAI) showing the similarities between both partially resistant lines with a delay and degeneration in the formation of the syncytia in comparison to the susceptible cultivar. Females at 30 DAI in partially resistant lines showed a delay in their development in comparison to the susceptible cultivar.
Project description:As part of the Globodera pallida (potato cyst nematode) genome project weare profiling the transcriptome of the parasite across its life cycle usingRNA-Seq. . This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/
Project description:Plant-parasitic nematodes (PPN) need to be adapted to survive in the absence of a suitable host or in hostile environmental conditions. Various forms of developmental arrest (including desiccation, cryopreservation, hatching inhibition and dauer stages) are used by PPN in order to survive these conditions and spread to other areas. Potato cyst nematodes (PCN) (Globodera pallida and G. rostochiensis) are frequently in a dessicated state unhatched nematodes within the egg dispersal unit inside the cyst. Long term survival seems to be associated primarily with species that have a very restricted host range which requires surviving unhatched in the absence of the host for extended periods of time. This paper shows fundamental changes in the response of quiescent and diapaused eggs of G.pallida to hydration and following exposure to tomato root diffusate using microarray gene expression analysis from a broad set of genes. Surprisingly, many unique genes were activated in the population of diapaused eggs. Transport activity was activated in both quiescent and diapaused eggs; however, the transport function genes were very different between them. Hydrated quiescent and diapaused eggs were markedly different indicating differences in adaptation for long term survival.