Botany & Plant Ecology.
We organized the information that was gathered during the inventory phase of this project into a prioritizing tool to allow for a quantitative ranking of sites with respect to their conservation value. A major component of this inventory work was the Florsitic Quality Assessment, a tool developed by the Michigan Department of Natural Resources. We found this measure helpful but not sufficient in itself for ranking sites. Therefore we developed a quantitative tool that used FQI as one criterion, but also included other factors such as presence and extent of non-native species, size of parcel, proximity to other protected areas (potential for corridor development), rarity of habitat type, evidence of physical disturbance, and ownership. We ranked a total of 68 sites using these criteria to generate a prioritized list of sites that are deserving of focused conservation efforts. All information gathered in the study was shared with landowners and with the Land Conservancy of West Michigan.
Leaves and Rhizomes of Later Tertiary Water Lily and Water Lily-Like Plants in the Western United States. Patrick F. Fields, Department of Botany and Plant Pathology, Michigan State University, East Lansing, MI 48824-1312; firstname.lastname@example.org
The form genus "Nymphaeites" is traditionally used to describe Neogene western North American megafossil leaves, petioles, rhizomes, and roots of water lily and water lily-like plants. Recent paleobotanical studies suggest that much of this leaf and rhizome material can be reliably assigned to extant Nymphaealean genera, namely: Nelumbo, Nuphar, or Nymphaea. Nelumbo is known from nearly complete remains in Reynolds Basin, Idaho, and as rhizomes in Stinking Water, Oregon. It is distinguished by swollen root-bearing nodes along the rhizomes, and the centrally peltate large orbicular leaves. Nuphar is known from leaves in Trout Creek, Oregon, and possibly from Eastgate, Nevada. It is distinguished by biconvex leaf scars on the rhizomes, and deeply cordare, ovate to oblong leaves with a prominent midrib and pinnate venation. While Nymphaea is known from leaves and rhizomes from Sonoma, California; Trapper Creek and Weiser, Idaho; Buffalo Canyon, Eastgate, Esmeralda, and Middlegare, Nevada; and Mascall, Stinking W ater, Succor Creek, and Trout Creek, Oregon It is distinguished by oval leaf scars along the rhizomes and cordate or offcentered peltare, orbicular to ovate leaves, with a faint midrib and weakly pinnate to radial venation.
Climate Reconstruction from Stable Isotope Ratios in Pleistocene Pocket Gopher Teeth. Karel Rogers, Biology Department, Grand Valley State University, 218 Padnos, Allendale, MI 49401-9403; and Yang Wang, 108 Carroway Building, Department of Geological Science, Florida State University, Tallahassee, FL 32306-4100
Previous work in the San Luis Valley of south-central Colorado and northern New Mexico at the Hansen Bluff and Sam Cave localities has reconstructed paleoclimate in the region during the interval from -0.69 Ma to -2.6 Ma. The fossil localities are at 2,300 and 2,680 m elevation, respectively, in the southern Rocky Mountains and are about 20km apart. Surface exposures at Hansen Bluff have been correlated to deep sea oxygen isotope core stages 18-23 and one of the glacial periods contained therein to the oldest "Nebraskan" till in southwestern Iowa. Deposits in Sam Cave correlate to Hansen Bluff on the basis of paleomagnetics, climate interpretation, and stage of microtine rodent evolution. In this paper, we present carbon and oxygen stable isotope data of herbivorous rodent teeth as indicators of change in the predominance of C3, C4, and CAM plants and extrapolate that change to changes in temperature and precipitation. These climate interpretations are compared with other climate proxy data sets, including os tracod stable isotopes and pollen analysis, that provide further insight into climate reconstruction. Together, the data provide a robust reconstruction of paleoclimate during a glacial/interglacial cycle at two localities that are in close proximity but at different elevations.
ITS DNA Sequences and Inflorescence Position in Species Traditionally Classified in Clidemia and Ossaea (Melastomataceae: Miconieae). Meridith A. Cleland and J. Dan Skean, Jr, Albion College, Department of Biology, Albion, MI 49224-1831; 517/629-0525; email@example.com, dskeangalbion.edu
Internal transcribed spacer (ITS) sequence data were used to evaluate the suspected polyphyly of the genera Clidemia D. Don and Ossaea DC., which have both terminal and axillary inflorescences and diverse floral morphology. A 1989 classification by Walter Judd placed axillary-flowered Clidemia and Ossaea in the genus Sagraea DC. In 1991 Judd and Skean placed most terminal-flowered West Indian Ossaea in the genus Leandra Raddi. Silica-gel-dried collections of nine species were made in the Dominican Republic in July 2000. Two additional species were collected in Belize in March 1999. Sequences from the ITS region 714 bases in length were aligned using Sequencher 3.0 and used in cladistic analyses with PAUP v. 4.0b4a Meriania involucrata (Desr.) Naud. was used as the out-group. A branch-and-bound search yielded three equally parsimonious trees 183 steps in length [CI=0.563, CI excluding uninformative characters=0.722; RI=0.792; RC=0.684.] The axillary-flowered species in the analysis, traditionally treated as Cl idemia rubra (Aubl.) Mart., Ossaea scalpta DC, and Clidemia fuertesii Cogn., considered by Judd to be members of the genus Sagraea, form a monophyletic group. The terminal-flowered species form a paraphyletic group. Among the terminal-flowered species studied, the insular species traditionally treated as Ossaea lima (Desr.) Triana [Leandra Lima (Desr.) Judd & Skean], and Ossaea limoides Urban [L. limoides (Urban) Judd & Skean] do not link closely with the continental L. mexicana Cogn.
The Vascular Flora of Hog Island, Charlevoix County, Michigan. C. Elizabeth Whately and Daniel Wujek, Department of Biology, Central Michigan University, Mount Pleasant, MI 48859
Historically to the present day, vascular plants have been collected on Beaver Island, but few specimens have been collected from the surrounding islands of the archipelago. The vascular flora of Hog Island, the fourth largest island of the archipelago, was inventoried. Over three hundred voucher specimens were collected at four different times between May and August, 2000. The number of families, genera, and species found on the island was determined. These data were compared to data previously published for the archipelago. Among the collected specimens were the threatened species Solidago houghtoni, Cirsium pitcheri, Iris lacustris, and Tanacetum huronense. Several new records for the Beaver Island group were documented.
A Plant Community Survey of Harbor Island National Wildlife Refuge, Chippewa County, Michigan. Michelle D. Selzer and Gregory Zimmerman, Department of Biology, Lake Superior State University, MI 49783
Harbor Island National Wildlife Refuge (HINWR) is located 2.5 miles north of Drummond Island, Chippewa County, Michigan. There is growing concern that white-tailed deer (Odocoileus virginianus) may be over-browsing areas of HINWR. The absence of many flowering plant species known to exist on the island raises concern regarding the island's diversity and current ecological state. The goals of this project were to further develop the plant inventory list with spring and summer flowering plants and to assess the effects of browsing on the flowering plant communities of HINWR. Predetermined areas were surveyed by walking transacts parallel to the shoreline and forest edge. Browse transects were used to assess browse damage for all recruited species less than 1.5 meters high. Flowering plant diversity was low in all areas surveyed. Invasive species and species of grasses co-dominated the areas surveyed. Many herbaceous and woody species were heavily browsed, and identification was difficult to determine. Little re cruitment of hardwood seedlings or saplings was observed. The browse surveys indicated that 73% of seedlings and saplings had been browsed. Habitat destruction by deer browsing and introduction of invasive plant species appear to contribute to the decline in flowering plant diversity of Harbor Island National Wildlife Refuge.
Natural Areas Inventory of the Greater Grand Rapids Region: Site Identification and Assessment. Sara Koetje, Daniel Westerhof, Randall Van Dragt, and David Warners, Calvin College, Department of Biology, 3201 Burton SE, Grand Rapids, MI 49546
The Greater Grand Rapids area is experiencing intense urban sprawl, and in the process many natural areas are being altered or replaced by urban development. To facilitate conservation efforts in this rapidly changing landscape, we undertook a two-year effort to inventory and prioritize the remaining natural areas within the 13 townships immediately surrounding Grand Rapids. By using Landscan aerial photographs on CD-ROM, presettlement vegetation maps, topographic maps, and soil survey maps, we identified all potentially high-quality natural sites greater than 20 acres in size (approximately 15 to 20 per township). Of the 498 landowners initially contacted, 180 granted us permission to do a site visit. For sites that appeared to have high natural quality, a second visit was made (68 sites total), during which we performed a plant inventory and Floristic Quality Assessment (FQI). Many notable discoveries were made, including several county record plant species, many rare habitat remnants, and several unusual a nimal sightings.
A Purple Color Form of Pitcher's Thistle. Edward G. Voss, University of Michigan Herbarium, North University Building, Ann Arbor, MI 48109-1057
Cirsium pitcheri (Compositae) is a thistle threatened under both state and federal law, endemic to the sandy shores and dunes of lakes Michigan, Huron, and Superior. It has hitherto been known to have heads only pale in color (white or cream). A form discovered in 1995 at the north end of Lake Michigan, in Mackinac County, has deep magenta corollas of a shade like that of the usual form of C. vulgare. This phenomenon is the reverse of the more frequent discovery of a pale (or albino) form of a normally colored species. The colony (at least 44 purple-headed plants in 1999) was almost destroyed by roadside "improvements" along U.S. Highway 2 in 2000. [This form will be discussed and named in Contr. Univ. Michigan Herb. Vol. 23: (in press) 2001.]
Exposure of Leaves of Arabidopsis thaliana to Silver Nitrate Induces Localized Changes in Peroxidase Activity. Jun Tsuji and Rebecca Reirzel, Siena Heights University, Biology Department, Adrian, MI 49221-1796
Pathogens inflict billions of dollars of damage on crop plants every year. However, despite the importance of plant diseases, our understanding of the mechanisms by which plants suppress the growth of potential pathogens is not complete. In many plants, the accumulation of peroxidase is correlated with disease resistance. In this study, we examined localized changes in leaf peroxidase activity in Arabidopsis thaliana. Exposure of the proximal region of Arabidopsis leaves to silver nitrate resulted in an increase in peroxidase activity in the distal region. Similarly, exposure of the distal region to silver nitrate caused an increase in peroxidase activity in the proximal area. Time course studies revealed that the increase in peroxidase activity was measurable after one hour of exposure to silver nitrate. By electrophoresis, the increase in peroxidase activity was associated with the accumulation of a basic peroxidase isoenzyme. These studies suggest that exposure of Arabidopsis leaves to silver nitrate induc ed the movement of a signal that resulted in increased peroxidase activity. Understanding the mechanism of peroxidase induction may lead to the development of new strategies of enhancing the disease resistance of plants.
Cadmium and Copper Accumulation in Transgenic Arabidopsis Plants. Wendy N. Wiesend and John C. Thomas, Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI 48128-1491
Heavy metal contamination of the soil is a growing problem in our industrialized world. Phytoremediation, or plants that clean-up these soils, is a new and exciting solution to the metal contamination problem. To create plants that are tolerant to heavy metals we introduced the yeast CUP-1 gene encoding the metallothionein protein (MT) into Arabidopsis thaliana plants. MTs are metal binding proteins that also act as anti-oxidants. Arabidopsis was used because of its small genome, rapid growth rate, and small size. Several individually transformed plants were selfed and their seeds recovered. The progeny transgenic plants were stressed for 7 days with solutions of either [CdCl.sub.2] or [CuSO.sub.4]. The leaves and stems were recovered and analyzed for Cd or Cu content using atomic absorption spectroscopy. Our results indicate that the CUP-1 gene does promote Cd and Cu accumulation in the leaves of Arabidopsis plants. DNA analysis of the Arabidopsis plants is underway. Similar studies in tobacco have also been done. This study develops a model system for understanding how genetic modification may enhance a plant's capacity for phytoremediation of heavy metal contaminated soils.
GSR Response Patterns to Various External Stimuli in Philodendron scandens. Levi O'Brian, Renee Schumacher, Michael J. Sharland, Amanda Thuemmel, Angela Wheeler, and Louis E. Cohen, Saginaw Valley State University, Department of Psychology, University Center, MI 48710
The use of a physiological measure such as Galvanic Skin Response (GSR) to monitor internal plant responses to external stimuli may provide a unique method to assess perception in plants. Since most plants fail to display detectable overt behaviors (at least from visual observation) internal physiological changes may substitute for overt behaviors and be utilized to assess the reactions of plants to stimuli. After suitable controls and GSR baselines were established, six philodendron subject plants received four different common environmental stimuli. It was hypothesized that evidence for perception of an externally applied stimulus would be indicated by a coinciding change in GSR tracings, with such changes being significantly different from baseline readings. Results were assessed by comparison of Pre(Baseline levels) and Post Stimulus GSR tracings.
MINISYMPOSIUM ON ENVIRONMENTAL SUSTAINABILITY
The Importance of Genetic Resource Conservation to Sustainable Agriculture. Sheila Blackman, Biology Department, Grand Valley State University, Allendale, MI 49401
Agriculture in most of the world has shifted or is shifting from being focused on small, family-owned farms growing a variety of crops for subsistence to large agribusiness operations growing crops for market. This shift is accompanied with a reduction in the number of genotypes under cultivation and is resulting in an erosion in the genetic diversity of crop species. Genetic diversity is the raw material for plant improvement whether through plant breeding or biotechnology. Thus, its maintenance is imperative for the sustainabiliry of food supplies. Current issues in plant genetic resources conservation will be discussed, including the state of the world's seed banks, the genetic pitfalls of ex situ preserves and how they are being addressed, the current status of genetic diversity in some of the world's major food crops, and current strategies and philosophies of seed banks trying to preserve mote and more crops with fewer and fewer resources.
Sustainable Forestry: Promise or Hope? Lowry C. Stephenson, Biology Department, Grand Valley State University, Allendale, MI 49401
Sustainable forestry, meeting the needs of the present without compromising ecological health, biodiversity, and economic benefits available to future generations, has been a prominent goal of professional forestry for more than 200 years. Meeting that goal has been mote problematic, as scientific understanding of what defines sustainabiliry has evolved and as individual practitioners compromised principles to meet economic and political realities. The most recent manifestation of this evolution is the "new forestry" developed in the 1990s. This approach is based on forest ecosystem management and is becoming a driving force in the practice of forestry in most of the developed nations. The goal of forest ecosystem management is to maintain sustainability of both the forest resource and forest ecosystem, by structure-based management at the landscape and single stand levels and by maintenance of long term ecological productivity, nutrient cycles, and natural pest resistance. Restoration of biodiversity, manage ment for wildlife and wetlands, and establishment of ecosystem reserves are typically part of this approach. The success of forest ecosystem management will be dependent on acceptance and participation by all interested stakeholders (industry, owners, interest groups, local governments), It frequently incorporates a certification [INCOMPLETE]
Tryptamine and Plant-Insect Protection. Frank Hanley and John C. Thomas, Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI 48128-1491
We are investigating the effect of the natural plant-produced alkaloid tryptamine on various life history traits of Drosophila melanogaster. Previous work indicated that transgenic plants accumulating tryptamine did not support pest insect reproduction. Secondly, tryptamine application was deleterious to Drosophila fecundity. In this study we have learned that 50% or greater mortality was observed in wild-type, white, plume, and prune mutant adult flies following 5-15 mM tryptamine treatment for 3-4 days. The mechanism of tryptamine insecticide action remains unknown. Iris believed that tryptamine lowers the metabolic rate of the fly. Using an oxygen electrode we are measuring oxygen levels in control and tryptamine treated whole fruit flies and isolated mitochondria. Decreased oxygen use by the insects may account in part for tryptamine toxicity. The long-range goal of this project is to determine the utility of tryptamine-producing plants against pest insects.
Specific Lipoxygenase Isoform May Mediate Wound Response in Soybean Vegetative Tissues. Lowry C. Stephenson, Biology Department, Grand Valley State University, Allendale, MI 49401, and Howard D. Grimes, School of Molecular Biosciences, Washington State University, Pullman, WA 99164
Lipoxygenases are dioxygenases found ubiquitously in higher plants and animals. They catalyze the hydroperoxidation of pentadiene moieties of long-chain fatty acids, initiating biosynthesis of regulator compounds, the best known of which in plants are the jasmonates. In plants increased lipoxygenase activity and accumulation of transcripts have been correlated with diverse physiological, developmental, and storage functions. Lipoxygenases are found as highly conserved multigene families. Eight genes have been cloned from soybean: three from seeds and five from vegetative tissues. We have characterized the vegetative lipoxygenase genes and demonstrated that they respond differentially to reproductive or vegetative sink limitation, erogenous nitrogen, methyl jasmonate, and diverse developmental and environmental factors. We have also demonstrated that specific lipoxygenase gene products accumulate differentially in discrete tissues and subcellular compartments and show diverse response to specific biochemical s ubstrates. Here we present data demonstrating that transcripts of one lipoxygenase isoform, LxE, are responsive to wounding treatments and may play a critical role in the wound response signaling pathway. Additional evidence suggests that the LxE protein may function in chloroplasts.
Expression of a Jasmonate-Responsive Proteinase is Correlated with Proteolytic Activity in Soybean Seedlings. Kelly N. Ballast, Matthew J. Christians, Justin T. Sybesma, and David S. Koetje, Biology Department, Calvin College, 3201 Burton Street SE, Grand Rapids, MI 49546
Plants emit methyl jasmonate as a volatile compound in response to various stresses including wounding, drought, and herbivory. We have identified a novel gene from a cDNA library prepared from soybean shoot tips after exposure to methyl jasmonate vapors. BLAST searches revealed that its deduced protein sequence is 40-70% similar to cysteine proteinases in legumes and other plants. Thus, we have tentatively named it jrp l, or jasmonzzre-responsive proreinase 1. The locations of putative catalytic amino acids of the active site appeared to be conserved as well. A genomic DNA blot revealed a single copy of this gene, suggesting that jrpl protein is structurally (and perhaps functionally) unique from other cysteine proteinases in soybean. RNA blotting experiments confirmed that jrpl is expressed in the shoot tips and cotyledons of soybean seedlings within five days of exposure to atmospheric methyl jasmonate; however, we were unable to detect expression in control plants not exposed to methyl jasmonate. Using az ocasein as a substrate, we were able to correlate patterns of irpi expression with increased proteolyric activity in crude extracts from soybean cotyledons and shoot tips exposed to methyl jasmonate. This proteolytic activity had an acidic pH optimum between 5 and 6, corresponding with the predicted isoelectric point of jrpl protein. We are tentatively proposing that jrpl may be involved in "metabolic reprogramming" of soybean seedlings upon exposure to methyl jasmonate, affecting source-sink relationships within the plant. Alternatively, jrpl may activate and/or process other jasmonate-induced proteins. This research was supported by a fellowship from the Calvin College Science Division and by the Biology Department.
The Chino del Tomate Virus of Tomato Plants. Abdo J. Najy and John C. Thomas, Department of Natural Sciences, University of Michigan--Dearborn, MI 48128-1491
The Chino del Tomate Virus, CdTV, is a circular, single-stranded DNA virus that infests dicotyledonous plants in the southern region of North America and Mexico. As a bipartite virus, CdTV requires two genomes to create severe symptoms ranging from leaf curling, stunting, and interveinal chlorosis. The CdTV A genome is responsible for encoding the ALl replication protein and the ARi encapsulation protein. The B genome encodes the BL1 and BR1 proteins, used in cell-to-cell and cytoplasm-nucleus transport, respectively. We have cloned linearized A and B genomes into pBS-BS plasmids. Transformed E. coli containing the genomes were mated with Agro bacterium LBA 4404 and C58. The Agrnbacrerium was then introduced to tomatoes. We observed some viral symptoms. Current studies use a new configuration of the CdTV genomes to optimize viral transmission. By understanding the complex genetics of the different genomes, future work will focus on producing an antisense RNA that can stop or decrease the proliferation of the disease in these plants.
Floral Developmental Regulation and Sexual Lability in Spinach. Edward M. Golenberg, Department of Biological Sciences, Wayne State University, Detroit, MI 48202
In dioecious, cultivated spinach, Spinacia oleracca, the presence or absence of reproductive organs is determined by organ primordia initiation rather than by degeneration of organ primordia as in maize, sorrel, and campion. Two lines of evidence demonstrate that sexual dimorphism in spinach is determined by facultative regulation of sex-specific genes. First, spinach B class homologs, SpAP3 and SpPl, are expressed throughout the male floral meristem before stamen primordia art formed, then subsequently, become restricted to stamen primordia. Expression of either gene is not detectable in any stage of female flower development. This implies that sex determination occurs at or upstream of B class gene expression, and that downstream targets of the B class genes will be differentially expressed in males and females. This also implies that these expression patterns may control the development of sexual dimorphism in spinach. Second, in two cultivars, exogenous [GA.sub.3] application results in a male development al bias, indicating that sex determination can be regulated upstream of the organ identity genes. Furthermore, a third cultivar does not exhibit a male bias in response to GA ,indicating that upstream sex determination genes are polymorphic. These results suggest that sexual lability itself can potentially evolve in this species.
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|Article Type:||Critical Essay|
|Date:||Mar 22, 2001|
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