Next Article in Journal
Next Article in Special Issue
Previous Article in Journal
Plants 2013, 2(4), 635-649; doi:10.3390/plants2040635
Article

Verbesina alternifolia Tolerance to the Holoparasite Cuscuta gronovii and the Impact of Drought

 and *
Received: 6 August 2013; in revised form: 25 September 2013 / Accepted: 9 October 2013 / Published: 18 October 2013
(This article belongs to the Special Issue Interaction Between Abiotic and Biotic Stresses in Plants)
View Full-Text   |   Download PDF [406 KB, uploaded 18 October 2013]   |   Browse Figures
Abstract: Holoparasites are nonphotosynthetic plants that acquire all resources from hosts. The holoparasite Cuscuta gronovii is native to much of the US with a broad host range including Verbesina alternifolia, an understory perennial. Both species grow in moderate to moist soils and occur in habitats that may experience prolonged or episodic drought. We applied the Wise-Abrahamson Limiting Resource Model (LRM) developed for plant-herbivore relations to examine the effects of pattern of drought stress on tolerance of V. alternifolia to parasitism by C. gronovii. Individual plants were assigned one of six treatments that were combinations of parasite (none or addition of parasite) and drought stress (well-watered, continuously-stressed, or pulse-stressed). After pulse-stressed plants had experienced two wet-dry cycles all plants were harvested. Parasitism strongly reduced both shoot and root mass and well-watered hosts exhibited the greatest decline, indicating reduced tolerance to parasitism when water was readily available. This is consistent with the LRM if parasitism limits photosynthates available to the host. However, parasitism increased allocation to shoot and this effect did not differ between well-watered and drought-stressed plants, indicating equal tolerance. This outcome is in accord with an alternative prediction of the LRM if hosts are not carbon limited. Total pot productivity was reduced by parasitism and drought stress, and this effect was greater for pulse-stressed than for continuously-stressed hosts. We discuss the applicability of the LRM for understanding the effects of drought on tolerance to parasitism.
Keywords: Cuscuta gronovii; focal resource; parasitism; pulse stressed; resource limitation; Verbesina alternifolia Cuscuta gronovii; focal resource; parasitism; pulse stressed; resource limitation; Verbesina alternifolia
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Export to BibTeX |
EndNote


MDPI and ACS Style

Evans, B.; Borowicz, V. Verbesina alternifolia Tolerance to the Holoparasite Cuscuta gronovii and the Impact of Drought. Plants 2013, 2, 635-649.

AMA Style

Evans B, Borowicz V. Verbesina alternifolia Tolerance to the Holoparasite Cuscuta gronovii and the Impact of Drought. Plants. 2013; 2(4):635-649.

Chicago/Turabian Style

Evans, Bethany; Borowicz, Victoria. 2013. "Verbesina alternifolia Tolerance to the Holoparasite Cuscuta gronovii and the Impact of Drought." Plants 2, no. 4: 635-649.

Plants EISSN 2223-7747 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert