<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Root-knot nematodes (RKN; <italic>Meloidogyne</italic> spp.) are obligate plant parasites that require constant communication with their host to establish and maintain specialized feeding cells. The intimacy of this interaction likely requires constant monitoring of host biology and behavior. As plant processes follow tightly regulated circadian and diurnal patterns, RKN may use similar cues to regulate aspects of this symbiosis. We interrogated RKN biology within the context of host diurnal rhythms throughout nematode development. At 24-hr post-inoculation, RKN penetrated host roots significantly more when inoculated during the night compared to the day. We excluded the possibility that this phenomenon is due to nematode perception of light penetrating the soil, as an identical phenomenon is observed under inverted light conditions. Additionally, when plants were allowed to equilibrate and adjust their light-driven clock under constant light conditions, the temporal variation in nematode penetration was abolished. This phenomenon is not present during earlier nematode developmental stages as egg hatch and infective juvenile mobility did not follow rhythmic patterns and are not affected by light. Taken together, it appears nematode host seeking and penetration are at least partially influenced by daily changes in plant root signaling and light does not have a direct effect on RKN developmental stages. Understanding the role and origin of circadian and diurnal rhythms in the plant–nematode interaction underscores the importance of exploiting basal plant biology to develop novel control methods for these pathogens.</p>
</abstract>

Root-knot nematodes (RKN; Meloidogyne spp.) are obligate plant parasites that require constant communication with their host to establish and maintain specialized feeding cells. The intimacy of this interaction likely requires constant monitoring of host biology and behavior. As plant processes follow tightly regulated circadian and diurnal patterns, RKN may use similar cues to regulate aspects of this symbiosis. We interrogated RKN biology within the context of host diurnal rhythms throughout nematode development. At 24-hr post-inoculation, RKN penetrated host roots significantly more when inoculated during the night compared to the day. We excluded the possibility that this phenomenon is due to nematode perception of light penetrating the soil, as an identical phenomenon is observed under inverted light conditions. Additionally, when plants were allowed to equilibrate and adjust their light-driven clock under constant light conditions, the temporal variation in nematode penetration was abolished. This phenomenon is not present during earlier nematode developmental stages as egg hatch and infective juvenile mobility did not follow rhythmic patterns and are not affected by light. Taken together, it appears nematode host seeking and penetration are at least partially influenced by daily changes in plant root signaling and light does not have a direct effect on RKN developmental stages. Understanding the role and origin of circadian and diurnal rhythms in the plant–nematode interaction underscores the importance of exploiting basal plant biology to develop novel control methods for these pathogens.

Root-knot nematodes demonstrate temporal variation in host penetration

Journal of Nematology

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running-head

Root-knot nematodes demonstrate diurnal rhythms:

Root-knot nematodes (RKN; Meloidogyne spp.) are obligate plant parasites that require constant communication with their host to establish and maintain...

Root-knot nematodes demonstrate temporal variation in host penetration

Published Online: Apr 13, 2020

Page range: 1 - 8

Received: Feb 07, 2020

DOI: https://doi.org/10.21307/jofnem-2020-037

Keywords
Root-knot nematodes, Temporal variation, Circadian rhythms, Bioassays, Nematode biology

© 2020 Shova Mishra et al., published by Sciendo.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Root-knot nematodes demonstrate temporal variation in host penetration

Published Online: Apr 13, 2020

Page range: 1 - 8

Received: Feb 07, 2020

DOI: https://doi.org/10.21307/jofnem-2020-037

KeywordsRoot-knot nematodes, Temporal variation, Circadian rhythms, Bioassays, Nematode biology

© 2020 Shova Mishra et al., published by Sciendo.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
Root-knot nematodes, Temporal variation, Circadian rhythms, Bioassays, Nematode biology