Plant Research Laboratory Research Articles

Peningkatan Produktivitas Tanah Sulfat Masam dan Hasil Padi Menggunakan Bioarang dari Limbah Industri Penggergajian Kilang Kayu

The study aims to analyze three aspects. (1) Formulation of biochar from wood refinery sawmill waste at pyrolysis temperatures of 450°C and 550°C with pyrolysis times of 2 and 4 hours. (2) The best wood refinery sawing waste biochar dosage to improve the chemical quality of acidic sulfate soil through improving soil pH, Al-dd, N, P, and K of the soil. (3) Growth and production of paddy on acidic sulfate soils by application of ameliorant biochar of waste sawmill wood mill. The research was conducted in acidic sulfate soil in a screen house in the Experimental Garden of the Faculty of Agriculture, Syiah Kuala University. Soil samples and biochar were analyzed at the Soil and Plant Research Laboratory of the Faculty of Agriculture. The study was an experiment using a factorial complete randomized design with two factors: the temperature and pyrolysis time and the dose of biochar. The results showed that the application of biochar waste from sawmill wood refineries had a very significant and significant effect on improving the quality of acidic sulfate soil and the growth and production of rice fields. The formulation of biochar at a pyrolysis temperature of 550°C for 2-hour pyrolysis with 20 tons/ha is the best improvement in acid sulfate soil quality, growth, and rice field production.
 
 Keywords: acid sulphate, biochar, paddy

Population genetics comparison of Lilioceris cheni (Coleoptera: Chrysomelidae) colonies released onto Dioscorea bulbifera in Southeastern U.S.A.

ABSTRACT Multiple importations of Lilioceris cheni, a defoliating beetle of the invasive air potato plant, were received by the ARS-Invasive Plant Research Laboratory from 2002 to 2012. The last two, in 2011 (China) and 2012 (Nepal), formed the basis of two colonies from which releases were made into six Southeastern U.S. States. Colony populations were examined using the mitochondrial COI sequence. Phylogenetics, evolutionary divergence, a haplotype network, population statistics, and migration models were generated for the two colonies, countries of origin, and the inferred populations (clades). Phylogenetics eliminated the possibility of cryptic speciation and alleviated the need for host-range testing of the 2012 Nepalese samples. Evolutionary divergence showed the Chinese colony was 1.65X as divergent as the Nepalese, but one Nepalese clade was the most distinctly different of all clades. AMOVA showed most (>70%) genetic variation resided within rather than between colonies. In contrast, AMOVAs showed high levels (>61.5%) of genetic variation between underlying clades with proportionally less variation within. The haplotype network showed broad agreement with the phylogeny. Clade C, from China, displayed the largest number of haplotypes and the largest mutation-scaled effective population size in MIGRATE software. The best MIGRATE models indicated that migration and descent followed the order of phylogenetic descent. The results suggest that the genetic diversity being offered to the adventive range by these very divergent colonies (and clades) is large and should support great ecological flexibility.

Optimizing CLEM protocols for plants cells: GMA embedding and cryosections as alternatives for preservation of GFP fluorescence in Arabidopsis roots.

Recently, a number of diverse correlative light and electron microscopy (CLEM) protocols have been developed for several model organisms. However, these CLEM methods have largely bypassed plant cell research, with most protocols having little application to plants. Using autophagosome identification as a biological background, we propose and compare two CLEM protocols that can be performed in most plant research laboratories, providing a good compromise that preserves fluorescent signals as well as ultrastructural features. These protocols are based on either the adaptation of a high pressure fixation/GMA acrylic resin embedding method, or on the Tokuyasu approach. Both protocols suitably preserved GFP fluorescence while allowing the observation of cell ultrastructure in plants. Finally, the advantages and disadvantages of these protocols are discussed in the context of multiscale imaging of plant cells.

USDA-ARS Poisonous Plant Research Laboratory: History and Current Research on Western North American Rangelands

On the Ground Poisonous plants on western North American rangelands have historically been troublesome to livestock producers. Research on toxic plants was initiated by the United States Department of Agriculture in the late 1890s to solve problems for the livestock industry. TheUnitedStatesDepartment ofAgricultureAgricultural Resource Service Poisonous PlantResearch Laboratory in Logan, Utah continues to provide research-based solutions to poisonous plant problems besetting livestock producers, hobby farmers and small holders, veterinarians, and extension personnel. Principal plants of current research interest include larkspur, lupine, locoweed, selenium accumulating plants, pyrrolizidine alkaloid-containing plants, and ponderosa pine.

Collections in the Plant Research Laboratory of The New York Botanical Garden

The Plant Research Laboratory at The New York Botanical Garden maintains a variety of research samples for biodiversity studies. The collections are the products of botanical exploration, laboratory research, collaborations, and donations from the scientific community. These collections are enumerated, and information about herbarium voucher specimens, the history of the collections, and their current use is provided.

Non-destructive high-throughput DNA extraction and genotyping methods for cotton seeds and seedlings.

Extensive use of targeted PCR-based genotyping is precluded for many plant research laboratories by the cost and time required for DNA extraction. Using cotton (Gossypium hirsutum) as a model for plants with medium-sized seeds, we report here manual procedures for inexpensive non-destructive high-throughput extraction of DNA suitable for PCR-based genotyping of large numbers of individual seeds and seedlings. By sampling only small amounts of cotyledon tissue of ungerminated seed or young seedlings, damage is minimized, and viability is not discernibly affected. The yield of DNA from each seed or seedling is typically sufficient for 1000 or 500 PCR reactions, respectively. For seeds, the tissue sampling procedure relies on a modified 96-well plate that is used subsequently for seed storage. For seeds and seedlings, the DNA is extracted in a strongly basic DNA buffer that is later neutralized and diluted. Extracts can be used directly for high-throughput PCR-based genotyping. Any laboratory can thus extract DNA from thousands of individual seeds/seedlings per person-day at a very modest cost for consumables (~$0.05 per sample). Being non-destructive, our approach enables a wide variety of time- and resource-saving applications, such as marker-assisted selection (MAS), before planting, transplanting, and flowering.

Mitigation of Larkspur Poisoning on Rangelands Through the Selection of Cattle

On the Ground • Toxic larkspur (Delphinium species) cause large economic losses from cattle deaths, increased management costs, and reduced utilization of pastures and rangelands. • We recommend that you obtain a risk assessment for larkspur on your range before turning out the cattle. Submit samples to USDA–ARS Poisonous Plant Research Laboratory for chemical evaluation at no charge. Information is available at: http://www.ars.usda.gov/main/site_main.htm?modecode=54-28-20-00 . • Selection of cattle resistant to larkspur poisoning could reduce cattle losses and improve rangeland utilization. • The use of genetic-based herd management decisions can provide a tool for livestock producers to improve their profit margin and enhance the economic sustainability of rural American communities.

Poisonous plants: Effects on embryo and fetal development

Poisonous plant research in the United States began over 100 years ago as a result of livestock losses from toxic plants as settlers migrated westward with their flocks, herds, and families. Major losses were soon associated with poisonous plants, such as locoweeds, selenium accumulating plants, poison-hemlock, larkspurs, Veratrum, lupines, death camas, water hemlock, and others. Identification of plants associated with poisoning, chemistry of the plants, physiological effects, pathology, diagnosis, and prognosis, why animals eat the plants, and grazing management to mitigate losses became the overarching mission of the current Poisonous Plant Research Laboratory. Additionally, spin-off benefits resulting from the animal research have provided novel compounds, new techniques, and animal models to study human health conditions (biomedical research). The Poisonous Plant Research Laboratory has become an international leader of poisonous plant research as evidenced by the recent completion of the ninth International Symposium on Poisonous Plant Research held July 2013 in Hohhot, Inner Mongolia, China. In this article, we review plants that negatively impact embryo/fetal and neonatal growth and development, with emphasis on those plants that cause birth defects. Although this article focuses on the general aspects of selected groups of plants and their effects on the developing offspring, a companion paper in this volume reviews current understanding of the physiological, biochemical, and molecular mechanisms of toxicoses and teratogenesis.

Plant Toxins That Affect Nicotinic Acetylcholine Receptors: A Review

Plants produce a wide variety of chemical compounds termed secondary metabolites that are not involved in basic metabolism, photosynthesis, or reproduction. These compounds are used as flavors, fragrances, insecticides, dyes, hallucinogens, nutritional supplements, poisons, and pharmaceutical agents. However, in some cases these secondary metabolites found in poisonous plants perturb biological systems. Ingestion of toxins from poisonous plants by grazing livestock often results in large economic losses to the livestock industry. The chemical structures of these compounds are diverse and range from simple, low molecular weight toxins such as oxalate in halogeton to the highly complex norditerpene alkaloids in larkspurs. While the negative effects of plant toxins on people and the impact of plant toxins on livestock producers have been widely publicized, the diversity of these toxins and their potential as new pharmaceutical agents for the treatment of diseases in people and animals has also received widespread interest. Scientists are actively screening plants from all regions of the world for bioactivity and potential pharmaceuticals for the treatment or prevention of many diseases. In this review, we focus the discussion to those plant toxins extensively studied at the USDA Poisonous Plant Research Laboratory that affect the nicotinic acetylcholine receptors including species of Delphinium (Larkspurs), Lupinus (Lupines), Conium (poison hemlock), and Nicotiana (tobaccos).

Management Practices to Reduce Lupine-Induced Crooked Calf Syndrome in the Northwest

On the Ground Lupines are legumes and may provide a source of protein and other nutrients late in the growing season. However, toxins are concentrated in the pods and will poison animals, especially sheep, if gluttonous consumption occurs. Risk of lupine-induced crooked calf syndrome depends on multiple factors including lupine population density, availability of other quality forages, weather/climate patterns, breeding schedules, stage of pregnancy, grazing management strategies, and others. Using stockers, open heifers, or other livestock species to graze lupine-infested pastures is one way to utilize high-risk rangelands. Do not over-graze as animals may be poisoned if forced to subsist on lupines. Identify lupines and obtain a chemical analysis for risk assessment on rangelands before turning pregnant cows out. Plant samples may be submitted to the USDA–Agricultural Research Service Poisonous Plant Research Laboratory for identification, chemical analysis, and a follow-up risk assessment at no charge....

Detection and diagnosis of rice-infecting viruses.

Rice-infecting viruses have caused serious damage to rice production in Asian, American, and African countries, where about 30 rice viruses and diseases have been reported. To control these diseases, developing accurate, quick methods to detect and diagnose the viruses in the host plants and any insect vectors of the viruses is very important. Based on an antigen–antibody reaction, serological methods such as latex agglutination reaction and enzyme-linked immunosorbent assay have advanced to detect viral particles or major proteins derived from viruses. They aid in forecasting disease and surveying disease spread and are widely used for virus detection at plant protection stations and research laboratories. From the early 2000s, based on sequence information for the target virus, several other methods such as reverse transcription-polymerase chain reaction (RT-PCR) and reverse transcription-loop-mediated isothermal amplification have been developed that are sensitive, rapid, and able to differentiate closely related viruses. Recent techniques such as real-time RT-PCR can be used to quantify the pathogen in target samples and monitor population dynamics of a virus, and metagenomic analyses using next-generation sequencing and microarrays show potential for use in the diagnosis of rice diseases.

The good and the bad of poisonous plants: an introduction to the USDA-ARS Poisonous Plant Research Laboratory.

This article provides an overview of the Poisonous Plant Research Laboratory (PPRL), about the unique services and activities of the PPRL and the potential assistance that they can provide to plant poisoning incidences. The PPRL is a federal research laboratory. It is part of the Agricultural Research Service, the in-house research arm of the U.S. Department of Agriculture. The mission of the PPRL is to identify toxic plants and their toxic compounds, determine how the plants poison animals, and develop diagnostic and prognostic procedures for poisoned animals. Furthermore, the PPRL's mission is to identify the conditions under which poisoning occurs and develop management strategies and treatments to reduce losses. Information obtained through research efforts at the PPRL is mostly used by the livestock industry, natural resource managers, veterinarians, chemists, plant and animal scientists, extension personnel, and other state and federal agencies. PPRL currently has 9 scientists and 17 support staff, representing various disciplines consisting of toxicology, reproductive toxicology, veterinary medicine, chemistry, animal science, range science, and plant physiology. This team of scientists provides an interdisciplinary approach to applied and basic research to develop solutions to plant intoxications. While the mission of the PPRL primarily impacts the livestock industry, spinoff benefits such as development of animal models, isolation and characterization of novel compounds, elucidation of biological and molecular mechanisms of action, national and international collaborations, and outreach efforts are significant to biomedical researchers. The staff at the PPRL has extensive knowledge regarding a number of poisonous plants. Although the focus of their knowledge is on plants that affect livestock, oftentimes, these plants are also poisonous to humans, and thus, similar principles could apply for cases of human poisonings. Consequently, the information provided herein could be of benefit to healthcare providers for human cases as well.

Phytotracker, an information management system for easy recording and tracking of plants, seeds and plasmids

BackgroundA large number of different plant lines are produced and maintained in a typical plant research laboratory, both as seed stocks and in active growth. These collections need careful and consistent management to track and maintain them properly, and this is a particularly pressing issue in laboratories undertaking research involving genetic manipulation due to regulatory requirements. Researchers and PIs need to access these data and collections, and therefore an easy-to-use plant-oriented laboratory information management system that implements, maintains and displays the information in a simple and visual format would be of great help in both the daily work in the lab and in ensuring regulatory compliance.ResultsHere, we introduce ‘Phytotracker’, a laboratory management system designed specifically to organise and track plasmids, seeds and growing plants that can be used in mixed platform environments. Phytotracker is designed with simplicity of user operation and ease of installation and management as the major factor, whilst providing tracking tools that cover the full range of activities in molecular genetics labs. It utilises the cross-platform Filemaker relational database, which allows it to be run as a stand-alone or as a server-based networked solution available across all workstations in a lab that can be internet accessible if desired. It can also be readily modified or customised further. Phytotracker provides cataloguing and search functions for plasmids, seed batches, seed stocks and plants growing in pots or trays, and allows tracking of each plant from seed sowing, through harvest to the new seed batch and can print appropriate labels at each stage. The system enters seed information as it is transferred from the previous harvest data, and allows both selfing and hybridization (crossing) to be defined and tracked. Transgenic lines can be linked to their plasmid DNA source. This ease of use and flexibility helps users to reduce their time needed to organise their plants, seeds and plasmids and to maintain laboratory continuity involving multiple workers.ConclusionWe have developed and used Phytotracker for over five years and have found it has been an intuitive, powerful and flexible research tool in organising our plasmid, seed and plant collections requiring minimal maintenance and training for users. It has been developed in an Arabidopsis molecular genetics environment, but can be readily adapted for almost any plant laboratory research.

Development of a new in vitro method to evaluate the photoprotective sunscreen activity of plant extracts against high UV-B radiation

Sunscreen efficiency of biomolecules against UV-B radiation was generally determined in vitro by cosmetic methods which are not well-adapted for routine ecophysiological and bio-guidance studies in plant research laboratories. In this article, we propose a new in vitro method to evaluate the sunscreen photoprotective activity of plant extracts against high UV-B radiation. Because photosynthetic pigments are one of the first targets of UV-B radiation in plants, the experimental design is based on the ability of the tested substances to limit the degradation of sodium magnesium chlorophyllin (SMC), a derivative compound of natural chlorophyll. SMC photodegradation comparatively to natural chlorophyll and related to temperature, concentration and sample solvent were analyzed in order to optimize the experimental parameters. Then, the method was validated by testing nine standard UV filters used in the European cosmetic industry and by comparing results of their activity with those of a reference in vitro procedure. Finally, the method was applied to coastal and marine crude plant extracts. Results have shown that our procedure can be a good alternative to cosmetic methods with a rapid, sensitive and reproducible evaluation of the sunscreen activity of either pure standards or crude plant extracts in small amounts (30mg).

The Discovery of Glyoxysomes: the Work of Harry Beevers

Sucrose Synthesis from Acetate in the Germinating Castor Bean: Kinetics and Pathway (Canvin, D. T., and Beevers, H. (1961) J. Biol Chem. 236, 988–995) Mitochondria and Glyoxysomes from Castor Bean Endosperm. Enzyme Constituents and Catalytic Capacity (Cooper, T. G., and Beevers, H. (1969) J. Biol. Chem. 244, 3507–3513)

An Introduced Insect Biological Control Agent Preys on an Introduced Weed Biological Control Agent

Biotic interference, especially by generalist predators, has been implicated in preventing establishment or limiting the impact of introduced weed biological control agents (Goeden & Louda 1976). Boreioglycaspis melaleucae Moore (Homoptera: Psyllidae) was released into Florida in 2002 as part of a classical biological control program targeting the ecological weed Melaleuca quinquenervia (Cav.) S. T. Blake (‘melaleuca’) and is now established and contributing to the suppression of melaleuca (Tipping et al. 2008). The multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) was introduced numerous times into the U.S. starting in 1916 as a biological control agent of Homoptera (Gordon 1985). Chapin & Brou (1991) first documented established populations in 1988 in Louisiana and Georgia. It appeared in Florida in the early 1990s where it feeds on soft scales, mealybugs, psyllids, whitefly larvae, and the eggs of Coleoptera and Lepidoptera (Michaud 2002). In 2007, we observed large populations of H. axyridis adults and larvae on melaleuca infested with B. melaleucae in our research plots at the USDA-ARS Invasive Plant Research Laboratory (IPRL) in Ft. Lauderdale, Florida (N 26°05’ W 80°14’). Although other predacious coccinellids were present including Brachiacantha decora Casey, Coleophora inaequalis (F.), and Olla v-nigrum (Mulsant), H. axyridis is considered a dominant intraguild species and has outcompeted many coccinellid species (Pervez & Omkar 2006). Our objective was to determine if H. axyridis would attack and sustain itself on B. melaleucae under laboratory conditions. Adult H. axyridis were collected from melaleuca growing at IPRL and provisioned with B. melaleucae nymphs in the laboratory until they oviposited. Individual egg masses were incubated at 27°C until larval emergence. First instars (n = 27) were confined in individual plastic containers (30 mL) with plastic snap lids along with a single melaleuca leaf containing various numbers of small (instars 1-3) and large (instars 4-5) of B. melaleucae in situ. This was done in lieu of transferring exact numbers because the nymphs are extremely delicate and easily injured or killed when handled. We strove to find leaves with similar numbers of small and large psyllids whose numbers we increased steadily as the H. axyridis larvae grew. For example, an average of 3 small and 1.5 large nymphs were added daily for first instar H. axyridis while fourth instars received 30.5 small and 14 large nymphs daily. Increases in provisioning were guided by the presence of surviving nymphs, which indicated that prey numbers were not limiting. Moisture was supplied with a moistened dental wick placed in the bottom of the container. Dead or missing nymphs were tallied every 13 d and a fresh leaf with their associated nymphs was added. Missing nymphs were assumed to have been consumed. Larval testing ended when H. axyridis died or pupated. Adult feeding trials were conducted for 7 d in the same manner with 12 adults that eclosed successfully from the larval feeding trials. Larvae and adults fed readily on B. melaleucae (Table 1). However, the mean (±SE) larval development time was 23.0 ± 0.6 d, which may indicate that the psyllid is not an optimal food source when compared to other prey. For example, H. axyridis completed larval development in 11.2 d when fed fresh eggs of Sitotroga cerealella (Olivier) (Abdel-Salam & Abdel-Baky 2001), 10.5 d when fed Myzus persicae (Sulzer) (Lanzoni et al. 2004), and 9.6 d when fed Aphis pisum Harris (Specty et al. 2003).

Larkspur Poison Weed: 100 Years of Delphinium Research

In 1909 the US Department of Agriculture (USDA) established a research station known as Camp Del phinium in the Gunnison National Forest near Gunnison, Colorado (Fig. 1). The purpose of this station, under the direction of Dr C. D. Marsh, was to study and find solutions to larkspur poisoning in cattle. As a result of this work, Farmers Bulletin 531, entitled Larkspur or Poison Weed, was published in 1916 detailing the current knowledge of larkspur intoxication in livestock, including management recommendations and treatment of intoxicated animals. Although much has changed in the livestock industry since 1909, larkspur poisoning is still a significant problem on ranges where it occurs. During the 100 years since the beginning of larkspur research by the USDA, numerous studies have been undertaken to solve the problem of larkspur poisoning in cattle, culminating in work currently underway at the Agricultural Research Service's Poisonous Plant Research Laboratory (PPRL) in Logan, Utah. The purpose of this article is to review important past findings and to highlight current research on larkspur at the PPRL. Delphinium (larkspur) species are members of the Ranunculacae family of plants that are commonly known as the buttercup family. Toxic larkspurs are found in the High Plains, foothill, and mountain rangelands of the western United States. The toxins in larkspurs are alkaloids, nitrogen-based compounds with potent pharmacological effects. Although the scope of the problem caused by toxic larkspur varies from year to year, the overall losses of cattle due to larkspur have remained remarkably consistent over time. For example, Marsh et al.1 described losses averaging 5% with some ranchers losing up to 200 head in a single season. More recently Pfister et al.2 have documented losses ranging from 2% to 5% and as high as 15% in places with large stands of toxic larkspur. Although the death of livestock is an obvious contribution to total dollar value losses, there are additional factors that must be considered. For example, stocker cattle grazing on typical rangeland where toxic larkspur grows have the potential to gain up to 2.5 pounds per day (1.1 kg/day), and many producers, upon losing animals to larkspur, move them off ranges that have high-quality forage. This results in significant amounts of wasted high-quality forage and increased feeding costs. Other hidden costs include the loss of lactating cows from larkspur poisoning. The loss of a cow typically leaves an early weaned, poorly performing calf and requires a replacement cow or heifer to be found if herd numbers are to stay constant.

Siemens helps establish MBR validation plant and water research laboratory

Siemens Water Technologies and Singapore's Public Utility Board (PUB) are collaborating on a full-scale membrane bioreactor (MBR) testing facility based at the island's Changi Water Reclamation Plant. Together with Singapore's Agency for Science, Technology and Research (A*Star) the Siemens business segment is also jointly establishing a laboratory that will focus on ways of improving water treatment technologies.

Native and introduced pollinators promote a self‐incompatible invasive woody vine (Paederia foetida L) in Florida1

Liu, H. (Department of Biology, University of South Florida, 4202 East Fowler Ave., SCA 110, Tampa, FL 33620), R. W. Pemberton (U.S. Department of Agriculture, Agricultural Research Service, Invasive Plant Research Laboratory, 3225 College Ave., Ft. Lauderdale, Florida 33314), and P. Stiling (Department of Biology, University of South Florida, 4202 East Fowler Ave., SCA 110, Tampa, FL 33620). Native and introduced pollinators promote an invasive woody vine (Paederia foetida L) in Florida. J. Torrey Bot. Soc. 133(2): 303– 311. 2006.—Little is known about the role of mutualistic relationships with local species in promoting or limiting introduced invasive plant species. In this study we carried out controlled pollination treatments and floral visitor watches at three sites varying in degree of human disturbance in central Florida to determine the breeding system and potential pollinators of Paederia foetida L (skunk vine). A native of eastern Asia, P. foetida is invasive in natural and human created habitats in the southern United States and Hawaii. Our data suggested that populations of P. foetida in Florida were self-incompatible and relied on both small-bodied halictid bees native to Florida and the introduced European honey bee for pollination. Visitation by native bees was more frequent in less disturbed sites, while the opposite was true for the honey bees. Pollinator limitation was evident at the relatively undisturbed and the highly disturbed sites, but not at the intermediate disturbed site. Mutualistic relationships with native pollinators as well as the introduced honey bee probably contributed to the establishment and spread of skunk vine in Florida.

Detection of single-copy genes in DNA from transgenic plants.

The development of increasingly sensitive chemiluminescent substrates and the ability to label probes with digoxigenin (DIG) by polymerase chain reaction (PCR) () has resulted in nonradioactive Southern analysis becoming the preferred method, in many plant research laboratories, for the detection of single-copy genes in DNA from transgenic plants. The previous, well established procedure for single-copy gene detection required the utilization of 32P-labeled probes. However, as well as safety issues, isotopic probes require labeling immediately prior to use with exposure times ranging from 1 d to 7 d. Isotopic probes are therefore laborious and time consuming. The procedure outlined here is rapid and simple and employs modification of two published protocols (,), using DIG-labeled nucleotides () that are incorporated into nucleic acid probes by PCR (,,). The analysis of a fragment of dissected transgene, attached to plant genomic DNA (border fragment analysis), gives information on transgene integrity and integration pattern into plant DNA, as well as transgene copy number. The number of bands, following chemilumi-nescent detection, corresponds to the number of transgene copies (see Fig. 1). The analysis of either the whole or part of the transgene, which has been dissected from the plant genomic DNA using restriction enzymes (internal fragment analysis), provides information on transgene copy number and integrity, but not the integration pattern. Open image in new window Fig. 1. Southern blot of DNA from transgenic lettuce plants (lanes 1–3 and 5–7) digested with HindIII to produce border fragments, followed by hybridization with a PCR-DIG-labeled luc (luciferase reporter gene) probe. Lanes 1, 3, 5, 6, and 7 represent transgenic plants with single-copy gene inserts; lane 2 is a transgenic plant containing two gene inserts, while lane 4, in which the sample does not hybridize to the PCR-DIG labeled luc probe, represents DNA derived from a nontransformed lettuce plant.