AmJPSB menu | GSB Journals Top Page

The Americas Journal of Plant Science and Biotechnology

Volume 5 Special Issue 1 2011
Plant science and biotechnology in North America: Focus on Canada II

AmJPSB
ISBN 978-4-903313-71-9

How to reference: Al-Taweel K, Fernando WGD (2011) Differential Gene Expression is a Promising Tool for Understanding Host–Pathogen Interactions. In: Al-Mughrabi K (Ed) Plant science and biotechnology in North America: Focus on Canada II. The Americas Journal of Plant Science and Biotechnology 5 (Special Issue 1), 1-10


Guest Editor

Khalil Al-Mughrabi

Potato Development Centre, New Brunswick Department of Agriculture and Aquaculture, Canada

www.gnb.ca/0029/10/0029100001-e.asp


CONTENTS AND ABSTRACTS

Khaled Al-Taweel (Canada/Syria), W.G. Dilantha Fernando (Canada) Differential Gene Expression is a Promising Tool for Understanding Host–Pathogen Interactions (pp 1-10)

Full Text [PDF]

 

ABSTRACT

Invited Review: Expression of genes is essential for normal development and pathological processes. Therefore, discovery of differentially expressed genes is critical for the understanding of the molecular mechanisms involved in normal and pathological states, as well as providing new insights for discovery of novel molecular genes. To date, a number of techniques such as microarray, suppression subtractive hybridization (SSH) and differentially displayed - reverse transcriptase - polymerase chain reaction (DD-RT-PCR) have been developed for novel gene discovery. Microarray analysis is one of the fastest-growing new technologies in the field of genetic research. Scientists are using microarrays that allow us to look at thousands of genes at one time and determine which are expressed in a particular cell type or under certain conditions. The SSH is a method that is used for the comparison of two RNA populations that differ in expression in response to a particular stimulus or environment, such as an infection by a pathogen, can identify differences in the abundance of specific transcripts that vary in a population dependent manner. DD-RT-PCR is a method based on PCR that allows systematic comparisons of expressed mRNA in the cells, so, is becoming more efficient nowadays to isolate and characterize genes differentially expressed among cells, tissues or individuals. In this mini-review, we will describe the techniques mentioned above that have been widely used in the field of molecular biology in the last decade to identify differentially expressed genes in many biological systems, including our own work in Fusarium head blight disease of wheat.

 

Kevin Baron, Claudio Stasolla (Canada) The Role of Stress during in Vivo and in Vitro Plant Reproductive Development: Implications for Cropping Systems and Germplasm Enhancement in Canada (pp 11-21)

Full Text [PDF]

 

ABSTRACT

Invited Review: High-yielding cereal and oilseed cultivars are integral components of modern cropping systems in Canada. Climate change occurring at both regional and global scales, along with increased frequency of extreme weather events, has resulted in greater emphasis upon yield stability or safety in local breeding programs. The reproductive development of crop and model plant species is particularly sensitive to environmental stress with undesirable reductions in seed yield linked to pollen sterility and ovule abortion along with defects in embryogenesis, storage product accumulation and seed maturation. In contrast to the detrimental role environmental stress plays in reducing harvestable yields, plants also employ controlled ‘stress’ programs at various checkpoints throughout the plant lifecycle. Modern in vitro tissue culture techniques which support breeding programs also employ stress as a means of reprogramming plant development. The following review covers recent molecular and physiological studies that have improved our understanding of the mechanism(s) through which both model and crop species cope with environmental or imposed stress during in vitro and in vivo reproductive development. Through approaches such as germplasm screening or genetic engineering plant biologists can utilize the information provided to enhance the stress tolerance of species of importance to the Canadian agriculture and forestry sectors.

 

M. Aminul Islam, Rona N. Sturrock, Abul K.M. Ekramoddoulla (Canada) Conifer Chitinases (pp 22-36)

Full Text [PDF]

 

ABSTRACT

Invited Review: Over the last two decades scientists have focused much attention on the physiological, molecular and functional biology of plant chitinases and there is considerable evidence suggest that chitinases play important roles in plant defense systems. Chitinases have also been shown to play a role in plant growth and development. Several review articles exist for chitinases of angiosperms but there is no such review for conifer chitinases, despite the economic and ecological significance of coniferous species in the world’s forests. Conifer chitinases consist of at least several classes of enzymes that are represented by small gene families. Class II (acidic) and class IV (basic) chitinases, expressed differentially over time and space, have been shown to be the major defense players in many conifer pathosystems. Class I and III chitinases are also reported in some conifers. This review discusses the current body of knowledge regarding conifer chitinases, including the molecular structure of chitinase genes and their regulation and function in conifer plants. Future potential uses for conifer chitinases as biopesticides and agents of biofuel production are also discussed.

 

Yvan Pelletier (Canada), Finbarr Horgan (The Philippines), Julien Pompon (Canada) Potato Resistance to Insects (pp 37-52)

Full Text [PDF]

 

ABSTRACT

Invited Review: Potato, Solanum tuberosum, is the fourth major crop and is grown around the world.It is subject to a large number of insect pests, but the Colorado potato beetle, the potato tuber moths and aphids are the most damaging.Crop resistance to these insects can alleviate problems caused by the use of synthetic insecticides.The diversity of wild tuber-bearing Solanum species offers a source of resistance to insects and pathogens; however, it has so far been under-utilized.This article reviews progress made in the development of insect resistant potato cultivars, as well as the biological and methodological challenges of developing insect resistant potato varieties. We conclude that the prospects of using wild species in future potato breeding programs are good, but, screening and experimental protocols need to be more holistic given the complexity of insect-potato interactions.

 

Godfrey P. Miles (USA), Marcus A. Samuel (Canada) Living in the O-zone: Ozone Formation, Ozone-Plant Interactions and the Impact of Ozone Pollution on Plant Homeostasis (pp 53-63)

Full Text [PDF]

 

ABSTRACT

Invited Review: Ozone is a key constituent of the terrestrial atmosphere. Unlike in the stratosphere, where ozone provides an essential barrier to incoming UV radiation, within the troposphere, it is a major secondary air pollutant that is estimated to cause more damage to plant life than all other air pollutants combined. In the troposphere, ozone is produced by photochemical oxidation of primary precursor emissions of volatile organic compounds (VOCs), carbon monoxide (CO), and sulfur dioxide (SO2) in association with elevated levels of oxides of nitrogen (NOx ≡ NO + NO2). Because of its strong oxidizing potential, ozone is damaging to plant life through oxidative damage to proteins, nucleic acids and lipids either directly or as a result of reactive oxygen species (ROS) derived from ozone decomposition. In plants, ROS, directly of indirectly derived from ozone exposure, are routinely scavenged by an array of enzymatic and non-enzymatic antioxidant defense mechanisms. The various ROS generated by ozone have strong influence on the plant’s biochemical and signaling network eliciting a wide range of responses including cell death.

 

Patricia E. Juskiw, James H. Helm, Donald F. Salmon (Canada) Breeding of Feed Grains for Western Canada (pp 64-77)

Full Text [PDF]

 

ABSTRACT

Invited Review: The production of livestock in western Canada is moving from a small farm system to a highly mechanized, intensive system of production with animals having superior genetics. With this change, the feed demand by the industry has been moving from using the cheapest feed available to the best quality available. Defining that quality has been a challenge. Different classes of livestock have different feed demands. As well, adoption of production practices to maintain sustainability has meant a shift from maximization of inputs/outputs to integrated crop management and optimization of resource use. Through development of tools to enhance selection, and maintenance and development of diverse germplasm, breeding of the feed grains barley (Hordeum vulgare L.) and triticale (X Triticosecale Witt.) has been an evolving effort throughout western Canada. In this review, we present the changes and challenges of feed grain breeding with focus on the breeding program at the Field Crop Development Centre (FCDC), Lacombe, AB.

 

Jaswinder Singh, Michael Ngadi, Anuradha Varier, Suha Jabaji (Canada) Jerusalem Artichoke: An Emerging Crop for Bioenergy and Bioproducts in North America (pp 78-89)

Full Text [PDF]

 

ABSTRACT

Invited Review: Bioenergy has become an urgent topic worldwide. States, nations, and companies are investing heavily to enhance their energy security and reduce fossil-fuel carbon emissions and pollution. Ethanol from sugarcane and maize are arguably the first renewable fuels to supplement petroleum-based fuels for use in transport. However, major drawbacks include the limited availability of suitable agricultural lands to grow these crops as well as their nutrient and water demands. Moreover, use of these crops has a negative impact on the food supply, especially with the use of maize (grain) as a feedstock. Jerusalem artichoke (Helianthus tuberosus L.) with its low input requirement, high ability to sequester C producing high amounts of biomass and inulin promises to be a good alternative for producing bioethanol with the added advantage of obtaining profitable bioproducts. Jerusalem artichoke (JA) is a tuberous rooted perennial plant which is a close relative of sunflower, an important oil seed crop. The storage carbohydrate of JA tubers is inulin, a fructan which is sweeter than sugar and has both nutritional and health benefits. Additionally, fructan containing food is also known for increasing the bioavailability of minerals and for stimulating immune system. The inulin present in tubers and stem can be converted to bioethanol. JA can be grown on marginal lands and even on post industrial site. We will review the potential of this crop for bioenergy while highlighting genetics, genomics, biotechnological and bioconversion efforts to turn this native Canadian crop to a viable feedstock for sustainable production of bioproducts.

 

Bin Zhu, Bao-Luo Ma (Canada) Genetically-Modified Crop Production in Canada: Agronomic, Ecological and Environmental Considerations (pp 90-97)

Full Text [PDF]

 

ABSTRACT

Invited Review: Since the commercial introduction of genetically modified (GM) crops for field cultivation in 1996, the area of GM crop production in Canada has increased from 0.14 million ha to the current 8.2 million ha. Inserting genes tolerant to herbicides and resistant to insect pests into the crops allows GM crops to be grown with fewer pesticide applications, thus reducing production cost. With the rapid adoption of GM crops, modern agricultural systems offer new crop management strategies so that both production efficiency and crop yield on a per-hectare basis are increased. As a result, there is a potential to offer better agricultural productivity than that conventional crops can provide. Despite the potential economic benefits, commercial production of GM crops at large has also raised some concerns about potential adverse effects on the environment. Over the past decade, there have been many research projects conducted to assess the risks posed by GM crops in the environment, especially for gene flow and non-target effects. Using a balanced approach to appraise agronomic benefits and environmental issues, this review summarizes the results obtained in numerous studies associated with GM crop production in Canada with special reference on the major GM crops of canola (Brassica spp.), maize or corn (Zea mays), and soybean (Glycine max), and the two main GM traits of herbicide tolerance (HT) and insecticidal toxins from a bacterium, Bacillus thuringiensis (Bt).

 

Sherryl R. Bisgrove (Canada) Microtubules and Root Responses to Mechanical Impedance and Gravity (pp 98-106)

Full Text [PDF]

 

ABSTRACT

Invited Mini-Review: Gravity and mechanical impedance represent two environmental cues that roots respond to as they grow through the soil. Roots generally grow down in response to gravity. However, rocks and other obstacles mechanically impede growth and roots need to maneuver around them as they penetrate into the soil. To do this roots change the direction in which they are growing by forming a bend that reorients the tip of the root. Microtubules are thought to play important roles in these root growth responses. By regulating the direction of cell expansion they are essential for ensuring that roots continue to elongate through the soil. In addition, microtubules are hypothesized to function in root responses to touch and gravity signals. These functions include signal detection, cytoplasmic organization in sensory columella cells, and the differential growth response that occurs during root bending. However, roles for microtubules in these responses are somewhat controversial since there are experiments that have produced conflicting results. We recently reported that Arabidopsis plants carrying mutations in the microtubule associated protein END BINDING 1 (EB1) have defects in their responses to touch/gravity stimuli (Bisgrove et al. 2008). These mutants open the door for analyses aimed at determining how and where in the response pathway EB1 and, by association, microtubules are involved. In animal and fungal cells EB1 appears to regulate the compliment of proteins that associate with microtubule plus ends. EB1 binding partners include proteins that function in signaling pathways, vesicle shuttling, and cross talk between the actin and microtubule cytoskeletons. Similar processes may occur during root responses to touch/gravity signals, although possible roles for EB1 are speculative. Further analyses of eb1 mutants and the identification of EB1 interactors in plants should provide additional insights.

 

Xianzhou Nie (Canada) Plant Viral Disease Management in the Genomics Era (pp 107-114)

Full Text [PDF]

 

ABSTRACT

Invited Review: Viral diseases pose a significant threat to crop production and quality. This is particularly true for crops in the tropical and subtropical regions and those whose propagation relies on vegetative tissues. Effective management of viruses and their vectors thus play a pivotal role in crop production. Various practices such as stringent phytosanitary measures, seed certification programs and vector controls have been widely applied in various crops. As more and more viruses, viroids included, have been fully sequenced and their transmission modes better understood, molecular detection/diagnosis/monitoring of target viruses/viroids in plants and vectors have been gradually development and employed. Modern technologies such as polymerase chain reaction (PCR)-based and nucleic acid hybridization-based techniques including PCR, real-time PCR and microarray demonstrate a great potential for efficient and accurate detection of a large number of viruses/viroids as well as other formats of pathogens in real-time, thus providing accurate guidance for controlling/managing the pathogens. Meanwhile, the genomic era technologies have also significantly expanded our understanding of the molecular basis of host-virus-vector interactions, which will undoubtedly improve virus disease management in various aspects including more efficient development and utilization of resistant cultivars especially those with multiple resistances and more efficient management of vectors and vector-mediated transmission.

 

Hugo Germain, Xin Li (Canada) Research on Molecular Plant-Microbe Interactions in Canada (pp 115-120)

Full Text [PDF]

 

ABSTRACT

Invited Mini-Review: The study of molecular plant-pathogen interactions is a very active field of research in Canadian universities and research centers. This is not surprising given that the Canadian economy is tightly bound to food crops and forest resources for domestic use and export. The goal of this mini-review is to provide an overview of the excellent research that is being done on this topic in Canada. The availability of funding for genome-scale projects on model and non-model crop plants has led the field of plant pathogen interactions into a new era. The different approaches used by researchers in Canada to decipher bacterial and fungal virulence strategies and the research tools currently being used to study the plant immune system will be discussed. Relevant work on Arabidopsis thaliana and Nicotiana benthamiana is included but most of the work discussed herein is related to non-model species.

 

Yaw L. Siow, Jay Petkau, Lindsei Sarna, Jennifer Enns, Karmin O (Canada) Berberine: Biochemical Analysis and Cardiovascular Benefits (pp 121-126)

Full Text [PDF]

 

ABSTRACT

Invited Mini-Review: Berberine is an alkaloid found in plants such as goldenseal (Hydrastis Canadensis L.), European barberry or jaundice berry (Berberis vulgaris L.), and Chinese goldthread or Huanglian (Coptis chinensis Franch.). Goldenseal can be grown in Canada and natural health products derived from this plant have been found on consumer shelves. In this review, a UPLC-based analysis of berberine in a goldenseal product is presented. The linear range for berberine is from 10 to 500 μg/mL with a coefficient of determination (R2) of 0.9996. Two major cardiovascular benefits of berberine are discussed: lipid lowering and antioxidant effects. Berberine has been shown to lower blood cholesterol through the stabilization of LDL receptor mRNA and to lower triglycerides through activation of AMPK, which in turn, targets two other enzymes involved in lipid biosynthesis, ACC and HMG CoA reductase. For its antioxidant effects, berberine has been shown to directly scavenge ROS/RNS species, to upregulate endogenous antioxidant defense mechanisms and to inhibit endogenous ROS/RNS-generating oxidases such as NADPH oxidase. Berberine has potential to be used as a complementary therapy for hyperlipidemia and for prevention and management of cardiovascular disease.

 

Aiming Wang (Canada), David J. Wang (Canada/USA), R. V. Chowda-Reddy, Hongyan Chen, Shengwu Ma (Canada) Development of a Plant-based Vaccine against Porcine reproductive and respiratory syndrome virus:Research Progress and Future Prospects (pp 127-131)

Full Text [PDF]

 

ABSTRACT

Invited Mini-Review: Porcine reproductive and respiratory syndrome virus (PRRSV) is one of a few important pathogens that threaten the pig industry worldwide. The disease caused by PRRSV is a major source of economic loss for pork producers. PRRSV infects pigs through the mucosal surface of the respiratory tract. Therefore, the production of an oral vaccine to induce specific mucosal immune response may represent the most effective approach to preventing PRRSV infection. As the production of safe subunit vaccines in systems such as mammalian, bacterial or insect cells is either impossible or too expensive, plants become a promising bioreactor. In the past several years, we have investigated the possibility of application of plants for the development of a low cost, orally administered, plant-based vaccine against PRRSV. We used the cholera toxin B subunit (CTB) of Vibrio cholerae as an adjuvant and the PRRSV GP5 or its neutralizing epitope (GP5-NE) as a vaccine antigen. We found GP5 or the CTB-GP5 fusion protein was no detectable in transgenic tobacco plants, though large amounts of corresponding RNA were evident. The expression level of CTB-GP5-NE in transgenic plants was in the range of 0.003 to 0.087% of total soluble proteins. The plant-derived CTB-GP5-NE was biologically active. To increase the yield of the CTB-GP5-NE recombinant protein in plant hosts, we developed a Soybean mosaic virus-based viral expression system. In this research review, we summarize our research progress and discuss challenges and future prospects of the development of a plant-based PRRSV vaccine.

© Global Science Books