Functional Variation of Two Novel Cellulases, -5 and -8, and the Heat Shock 90 Gene, -90, in and Their Expression in Response to Different Temperature Stress

Functional characterization of two novel endoglucanase genes, -5 and -8, of the root-lesion nematode was carried out. In situ-hybridization experiments revealed that -8 transcript was localized in the pharyngeal glands. Silencing of -5 and -8 resulted in a significant reduction of expression level (52% and 67%, respectively). Furthermore, the silencing of -8 determined a reduction (41%) in nematode reproduction, suggesting that treated nematodes are much less able to process food. Surprisingly, no significant difference on reproduction rate was observed with -5 dsRNA nematodes, suggesting a neofunctionalization of -5 despite the high similarity with nematode endoglucanases. species are poikilothermic organisms showing close relationships with the environmental temperature. The effects of different temperature ranges revealed that the reproductive potential of increased with increasing temperature from 23 °C to 28 °C, but no reproduction was observed at 33 °C. In real time, increasing temperature from 23 °C to 28 °C the heat shock gene -90 was differentially expressed in adult stages, while the levels of the effector genes -1 and -8 in females showed no significant differences compared to those observed at 23 °C, only in males -8 level decreased (45%). The upregulation of -90 in both adult stages suggests a protective mechanism in order to cope with unfavorable environmental conditions.