Let the environment decide: Sex determination in the plant parasitic cyst nematodes Heterodera schachtii
M. ANJAM (1), C. Matera (1), M. Sobczak (2), F. Grundler (3), S. Siddique (1) (1) Moleculare Phytomedicine, University Bonn, Germany; (2) Department of Botany, Warsaw University of Life Sciences, Poland; (3) Molecular Phytomedicine, University of Bonn, Germany

Plant-parasitic cyst nematodes are destructive pests that induce long-term syncytial nurse cells in the roots of host plant. Cyst nematodes are sexually dimorphic but differentiation into male or female is under environmental control. The probability of a juvenile to become a female is higher in the case of favourable conditions, whereas mainly male nematodes develop under adverse conditions. However, it is not clear, whether this phenomenon is due to epigenetic sex determination or differential mortality of one sex. In present studies we developed and validated a method to predict the sex of the beet cyst nematode Heterodera schachtii during early stages of their life cycle in host plant Arabidopsis. The putative male-associated (MAS) and female-associated syncytial (FAS) cells were isolated by laser microdissection. Total RNA was extracted to perform a transcriptome analysis via microarrays. The data analysis revealed that genes for defence responses, nutrient deficiency and starvation were preferentially upregulated in MAS as compared to FAS. Therefore, we hypothesize that the syncytia where plant reacts by turning on defence genes and limiting nutrient availability may signal juveniles to develop as male. Juveniles that are able to overcome plant defence responses most likely will become female. To validate this hypothesis, we generated a number of promoter::reporter and loss-of-function mutant lines. In this way, we will elucidate a 100-years-old biological problem.

Abstract Number: P7-153
Session Type: Poster