Morphological and genetic variation in <i>Egregia menziesii</i> over a latitudinal gradient

Henkel, Sarah K.; Hofmann, Gretchen E.; Whitmer, Allison C.

doi:10.1515/bot.2007.019

Cited by 13 publications

(5 citation statements)

References 77 publications

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“…(The lack of significance for habitat as a single factor is likely due to the fact that overall magnitude of hsp70 expression was similar between the 2 habitats.) E. menziesii exhibits morphological variability among sites that seems to be a response to environmental conditions (Henkel et al 2007) and exhibited population specific responses to heat stress that varied with latitude in previous hsp70 investigations (Henkel & Hofmann 2008). Thus, the significant differences observed in this physiological measure between habitats in our study were not unexpected.…”

Section: Habitat Differencessupporting

confidence: 56%

Interspecific and interhabitat variation in hsp70 gene expression in native and invasive kelp populations

Henkel

Kawai²,

Hofmann³

2009

Mar. Ecol. Prog. Ser.

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This study characterized the response to thermal stress in 3 kelp species to contribute to the understanding of the role of the heat shock response in species distributions and in native-invasive species interactions. We sampled the invasive kelp Undaria pinnatifida in its native range in Japan and its introduced range in California, USA, to investigate small-and large-scale differences in its response to temperature stress. We then conducted similar experiments on native kelp species in different habitats in California to investigate differences in the response among species and habitats. We examined temperature response by measuring the induction of the gene (hsp70) that encodes for heat shock protein 70 (Hsp70), which protects cellular proteins from mis-folding and degradation by environmental stress. Individuals of U. pinnatifida, and the native California species Egregia menziesii and Pterygophora californica were heat-shocked at a range of temperatures, and mRNA was extracted and analyzed for expression of hsp70. Significant differences in the timing and magnitude of hsp70 induction were observed between intertidal and harbor populations of U. pinnatifida within a few meters of each other in Japan, indicating environmentally driven variability in this response. Similarly, intertidal and subtidal populations of E. menziesii showed different responses, with subtidal E. menziesii populations responding more like subtidal P. californica populations. Native California species showed similar magnitudes of expression across all population, while U. pinnatifida collected from California harbors exhibited a more robust hsp70 response than native California species but was similar in magnitude to Japanese populations sampled.KEY WORDS: Kelp · hsp70 · Invasive · Native · Thermotolerance · qPCR · Undaria Resale or republication not permitted without written consent of the publisherIntertidal kelp populations exhibit faster heat shock gene up-regulation than submerged populations. Inset shows PCR amplification vs. cycle.

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Section: Habitat Differencessupporting

confidence: 56%

Interspecific and interhabitat variation in hsp70 gene expression in native and invasive kelp populations

Henkel

Kawai²,

Hofmann³

2009

Mar. Ecol. Prog. Ser.

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“…Morphological seaweed traits are associated with herbivory pressure, abiotic environment, and phylogenetic lineage, and their relationships with latitude are variable (Hay , Henkel et al. , Santelices et al. ), so clearly this would be an interesting question to further pursue.…”

Section: Discussionmentioning

confidence: 99%

“…The logistical benefits of using freeze-dried tissue in order to standardize food quality and allow us to assay seaweeds that were collected thousands of kilometers and months apart come at the cost of minimizing morphological traits. Morphological seaweed traits are associated with herbivory pressure, abiotic environment, and phylogenetic lineage, and their relationships with latitude are variable (Hay 1981, Henkel et al 2007, Santelices et al 2009), so clearly this would be an interesting question to further pursue. Pennings et al (2001) compared northern and southern Spartina populations and found that southern Spartina was significantly less palatable in fresh tissue assays (see also Long et al 2011), but when lyophilized tissue was tested, the significance was reduced (Siska et al 2002).…”

Section: Discussionmentioning

confidence: 99%

Declines in plant palatability from polar to tropical latitudes depend on herbivore and plant identity

Demko

Amsler

Hay

et al. 2017

Ecology

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Long-standing theory predicts that the intensity of consumer-prey interactions declines with increasing latitude, yet for plant-herbivore interactions, latitudinal changes in herbivory rates and plant palatability have received variable support. The topic is of growing interest given that lower-latitude species are moving poleward at an accelerating rate due to climate change, and predicting local interactions will depend partly on whether latitudinal gradients occur in these critical biotic interactions. Here, we assayed the palatability of 50 seaweeds collected from polar (Antarctica), temperate (northeastern Pacific; California), and tropical (central Pacific; Fiji) locations to two herbivores native to the tropical and subtropical Atlantic, the generalist crab Mithraculus sculptus and sea urchin Echinometra lucunter. Red seaweeds (Rhodophyta) of polar and temperate origin were more readily consumed by urchins than were tropical reds. The decline in palatability with decreasing latitude is explained by shifts in tissue organic content along with the quantity and quality of secondary metabolites, degree of calcification or both. We detected no latitudinal shift in palatability of red seaweeds to crabs, nor any latitudinal shifts in palatability of brown seaweeds (Phaeophyta) to either crabs or urchins. Our results suggest that evolutionary pressure from tropical herbivores favored red seaweeds with lower palatability, either through the production of greater levels of chemical defenses, calcification or both. Moreover, our results tentatively suggest that the ‘tropicalization’ of temperate habitats is facilitated by the migration of tropical herbivores into temperate areas dominated by weakly defended and more nutritious foods, and that the removal of these competing seaweeds may facilitate the invasion of better-defended tropical seaweeds.

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“…2002, Henkel and Murray 2007, Henkel et al. 2007). Previous studies have found that Egregia compensated for this loss in a similar manner to Macrocystis by increasing the branching of fronds from the base, as well as forming new frond branches from damaged rachis edges (Black 1974, 1976).…”

Section: Figmentioning

confidence: 99%

Sublethal biomass loss in Egregia menziesii (Phaeophyceae) reveals diffuse meristem tissue

Fulton‐Bennett

2021

Journal of Phycology

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Sublethal biomass loss has been found to have a variety of effects on marine macroalgae, from decreasing reproductive output to increasing individual survival and frond density. The ability of an individual to recover and persist through herbivore and wave damage is facilitated by the location of several meristematic growth regions throughout an individual. In kelps (Order Laminariales), meristems are found basally at the holdfast, at the base of each blade, and/or apically on each frond. In the intertidal kelp Egregia menziesii, fronds are thought to have an intercalary meristem at a transition zone between the main frond's midrib and a small terminal lamina. This study examined the effect of removing the terminal blade and transition zone on the elongation of the frond and found no significant difference in growth, contrary to expectations. Elongation occurred in the 30 cm of midrib at the apical end of fronds and was not isolated at the base of the terminal lamina as was previously thought. These results indicate the presence of a diffuse meristematic growth region that has not been reported in other kelps and may be an advantage for this intertidal species.

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Morphological and genetic variation in Egregia menziesii over a latitudinal gradient

Cited by 13 publications

References 77 publications

Interspecific and interhabitat variation in hsp70 gene expression in native and invasive kelp populations

Interspecific and interhabitat variation in hsp70 gene expression in native and invasive kelp populations

Declines in plant palatability from polar to tropical latitudes depend on herbivore and plant identity

Sublethal biomass loss in Egregia menziesii (Phaeophyceae) reveals diffuse meristem tissue

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