Strategies for expression of foreign genes in plants. Potential use of engineered viruses

Advances in gene transfer techniques for higher plants have already permitted important achievements towards crop protection and improvement using recombinant DNA technology. Besides plant genetic engineering, the possible use of plant viruses to express foreign genes could be of considerable interest to plant biotechnology. However, insuring containment of engineered viruses for environmental use is an important safety issue that must be addressed.     

Prospects for crop production under drought: research priorities and future directions

The efficient use of water supplies requires a systems approach that encompasses all aspects of making water available and its use within society that must recognise global issues. Increasing the efficiency of water use within agricultural systems is an essential priority in many regions including the Mediterranean. This review examines the research priorities, the prospects for crop and soil management and plant breeding and biotechnology that are needed to achieve high stable yield under drought in the Mediterranean. Research must combine the latest genomics resources including quantitative genetics, genomics and biomathematics with an ecophysiological understanding of the interactions between crop plant genotypes and the growing environment to better inform crop improvement.     

Biotechnology for Enhanced Nutritional Quality in Plants

With almost 870 million people estimated to suffer from chronic hunger worldwide, undernourishment represents a major problem that severely affects people in developing countries. In addition to undernourishment, micronutrient deficiency alone can be a cause of serious illness and death. Large portions of the world population rely on a single, starch-rich crop as their primary energy source and these staple crops are generally not rich sources of micronutrients. As a result, physical and mental health problems related to micronutrient deficiencies are estimated to affect around two billion people worldwide. The situation is expected to get worse in parallel with the expanding world population. Improving the nutritional quality of staple crops seems to be an effective and straightforward solution to the problem. Conventional breeding has long been employed for this purpose but success has been limited to the existing diversity in the gene pool. However, biotechnology enables addition or improvement of any nutrient, even those that are scarce or totally absent in a crop species. In addition, biotechnology introduces speed to the biofortification process compared to conventional breeding. Genetic engineering was successfully employed to improve a wide variety of nutritional traits over the last decade. In the present review, progress toward engineering various types of major and minor constituents for the improvement of plant nutritional quality is discussed.     

Bioengineering of crop plants and resistant biotype evolution in insects: Counteracting coevolution

The use, as opposed to the procurement, of transgenic crop plants is discussed in this paper. Transgenic crop plants must not be used until appropriate strategies for their use have been designed and not before crop plants with a variety of insect defenses have been developed. The use of a crop plant with a single defense will pose as strong a selection pressure as the use of a single synthetic insecticide, since insect herbivores are able to evolve effective counter-defenses. The defenses of insects in natural plant-insect associations and with regard to synthetic insecticides are described to demonstrate that there is nothing unique about insecticide resistance. It is the inevitable alternative to local extinction in response to a persistent and predictable selection pressure. Plants counteract insect defensive evolution by keeping the selection pressure as variable as possible. This leads to the conclusion that the best use of biotechnology in crop protection is to reintroduce chemical diversity into crop plants.     

Induction of abiotic stress tolerance in plants by endophytic microbes

Endophytes are micro‐organisms including bacteria and fungi that survive within healthy plant tissues and promote plant growth under stress. This review focuses on the potential of endophytic microbes that induce abiotic stress tolerance in plants. How endophytes promote plant growth under stressful conditions, like drought and heat, high salinity and poor nutrient availability will be discussed. The molecular mechanisms for increasing stress tolerance in plants by endophytes include induction of plant stress genes as well as biomolecules like reactive oxygen species scavengers. This review may help in the development of biotechnological applications of endophytic microbes in plant growth promotion and crop improvement under abiotic stress conditions.

Significance and Impact of the Study

Increasing human populations demand more crop yield for food security while crop production is adversely affected by abiotic stresses like drought, salinity and high temperature. Development of stress tolerance in plants is a strategy to cope with the negative effects of adverse environmental conditions. Endophytes are well recognized for plant growth promotion and production of natural compounds. The property of endophytes to induce stress tolerance in plants can be applied to increase crop yields. With this review, we intend to promote application of endophytes in biotechnology and genetic engineering for the development of stress‐tolerant plants.     

Sugarcane biotechnology: The challenges and opportunities

Summary Commercial sugarcane, belonging to the genus Saccharum (Poaceae), is an important industrial crop accounting for nearly 70% of sugar produced worldwide. Compared to other major crops, efforts to improve sugarcane are limited and relatively recent, with the first introduction of interspecific hybrids about 80 yr ago. Progress in traditional breeding of sugareane, a highly polyploid and frequently aneuploid plant, is impeded by its narrow gene pool, complex genome, poor fertility, and the long breeding/selection cycle. These constraints, however, make sugarcane a good candidate for molecular breeding. In the past decade considerable progress has been made in understanding and manipulating the sugarcane genome using various biotechnological and cell biological approaches. Notable among them are the creation of transgenic plants with improved agronomic or other important traits, advances in genomics and molecular markers, and progress in understanding the molecular aspects of sucrose transport and accumulation. More recently, substantial effort has been directed towards developing sugarcane as a biofactory for high-value products. While these achievements are commendable, a greater understanding of the sugarcane genome, and cell and whole plant physiology, will accelerate the implementation of commercially significant biotechnology outcomes. We anticipate that the rapid advancements in molecular biology and emerging biotechnology innovations would play a significant role in the future sugarcane crop improvement programs and offer many new opportunities to develop it as a new-generation industrial crop.     

Forestry's fertile crescent: the application of biotechnology to forest trees

Relative to crop plants, the domestication of forest trees is still in its infancy. For example, the domestication of many crop plants was initiated some 10,000 years ago in the so-called 'Fertile Crescent' of the Middle East. By contrast, the domestication of forest trees for the purposes of producing more fibre began in earnest in the last half century. The application of biotechnology to forest trees offers a great potential to hasten the pace of tree improvement for desirable end uses. This review outlines some of the progress that has been made in the application of biotechnology to forest trees, and considers the prospects for biotechnologically based tree improvement in the future.     

Future research directions in plant signal transduction mechanisms

Photosynthesis is the ultimate driving force behind world food production. Modern agricultural practices have done much to maximize the benefits of photosynthesis through better land management and intensive crop breeding. However, enhancement in grain production is becoming increasingly dependent on biotechnology with every improvement becoming more difficult to achieve. With several crop species nearing the physical limits of grain production, more attention will be given to methods that enable farmers to consistently attain maximum yields. These efforts focus in part on how plants respond to the biotic and abiotic stresses that can significantly reduce potential yields, including the study of plant signal transduction pathways related to stress responses. Strong evidence is emerging that these pathways share many similarities to classical mammalian receptor systems including tyrosine-kinase receptors and G protein-coupled receptors. Several putative receptor-like proteins have been identified in maize and provide vast opportunities for studying plant signal transduction mechanisms. The elucidation of plant signaling pathways combined with modern technologies will not only serve to push harvest yields closer to the maximum theoretical levels but may also provide opportunities for actually increasing the theoretical maximum.     

Industrial oils from transgenic plants

Unusual fatty acids that have useful industrial properties occur widely in the seed oils of many non-agronomic plant species. Researchers are attempting to use biotechnology to produce high levels of these fatty acids in the seeds of existing crop plants. cDNAs for a wide variety of unusual fatty acid biosynthetic enzymes have been identified, particularly through the use of expressed sequence tags. However, it has not yet been possible to use these cDNAs to produce large amounts of unusual fatty acids in seeds of transgenic plants. This difficulty points to the need for a greater understanding of fatty acid metabolism in oilseeds.     

Current and future editing reagent delivery systems for plant genome editing

Many genome editing tools have been developed and new ones are anticipated; some have been extensively applied in plant genetics, biotechnology and breeding, especially the CRISPR/Cas9 system. These technologies have opened up a new era for crop improvement due to their precise editing of user-specified sequences related to agronomic traits. In this review, we will focus on an update of recent developments in the methodologies of editing reagent delivery, and consider the pros and cons of current delivery systems. Finally, we will reflect on possible future directions.     

Jatropha curcas: a review on biotechnological status and challenges

Plant tissue culture and molecular biology techniques are powerful tools of biotechnology that can complement conventional breeding, expedite crop improvement and meet the demand for availability of uniform clones in large numbers. Jatropha curcas Linn., a non-edible, eco-friendly, non-toxic, biodegradable fuel-producing plant has attracted worldwide attention as an alternate sustainable energy source for the future. This review presents a consolidated account of biotechnological interventions made in J. curcas over the decades and focuses on contemporary information and trends of future research.     

Current state of biotechnology in Turkey

Biotechnology is an interdisciplinary branch of science that encompasses a wide range of subjects like genetics, virology, microbiology, immunology, engineering to develop vaccines, and so on and plays a vital role in health systems, crop and seed management, yield improvement, agriculture, soil management, ecology, animal farming, cellular process, bio statistics, and so on. This article is about activities in medical and pharmaceutical biotechnology, environmental biotechnology, agricultural biotechnology and nanobiotechnology carried out in Turkey. Turkey has made some progress in biotechnology projects for research and development.     

<Emphasis Type="Italic">Rhizobia species</Emphasis>: A Boon for “Plant Genetic Engineering”

Since past three decades new discoveries in plant genetic engineering have shown remarkable potentials for crop improvement. Agrobacterium Ti plasmid based DNA transfer is no longer the only efficient way of introducing agronomically important genes into plants. Recent studies have explored a novel plant genetic engineering tool, Rhizobia sp., as an alternative to Agrobacterium, thereby expanding the choice of bacterial species in agricultural plant biotechnology. Rhizobia sp. serve as an open license source with no major restrictions in plant biotechnology and help broaden the spectrum for plant biotechnologists with respect to the use of gene transfer vehicles in plants. New efficient transgenic plants can be produced by transferring genes of interest using binary vector carrying Rhizobia sp. Studies focusing on the interactions of Rhizobia sp. with their hosts, for stable and transient transformation and expression of genes, could help in the development of an adequate gene transfer vehicle. Along with being biologically beneficial, it may also bring a new means for fast economic development of transgenic plants, thus giving rise to a new era in plant biotechnology, viz. “Rhizobia mediated transformation technology.”     

Biotechnology: Genetic improvement of sorghum (Sorghum bicolor (L.) Moench)

Summary This report reviews the contributions to the improvement of sorghum (Sorghum bicolor (L.) Moench) through traditional approaches with emphasis on the application of biotechnological methods. Strategies include breeding for higher yield, improved grain quality, and biotic and abiotic stress tolerance. Hybrid development and polyploidy breeding are also discussed. Plant breeders, working in concert with biotechnologists, have developed new powerful tools for plant genetic manipulation and genotype evaluation that will significantly improve the efficiency of plant breeding. Improving sorghum through biotechnology is the latest in a long series of technologies that have been applied to this crop. Five basic tools of technology have been developed for sorghum improvement: (1) in vitro protocols for efficient plant regeneration; (2) molecular markers; (3) gene identification and cloning; (4) genetic engineering and gene transfer technology to integrate desirable traits into the sorghum genome; and (5) genomics and germplasm databases. Reports on studies involving the problems, progress, and prospects for utilizing the biotechnological methods for sorghum improvement are discussed.     

Sequencing crop genomes: approaches and applications

Many challenges face plant scientists, in particular those working on crop production, such as a projected increase in population, decrease in water and arable land, changes in weather patterns and predictability. Advances in genome sequencing and resequencing can and should play a role in our response to meeting these challenges. However, several barriers prevent rapid and effective deployment of these tools to a wide variety of crops. Because of the complexity of crop genomes, de novo sequencing with next-generation sequencing technologies is a process fraught with difficulties that then create roadblocks to the utilization of these genome sequences for crop improvement. Collecting rapid and accurate phenotypes in crop plants is a hindrance to integrating genomics with crop improvement, and advances in informatics are needed to put these tools in the hands of the scientists on the ground.     

转基因作物将为我国农业发展注入新动力

随着基因组学研究和生物技术的不断突破,应用生物技术改良农作物品种正成为引发新的农业技术革命的关键。由于转基因品种在生产上表现出的巨大效益,其研发和产业化在全球迅猛发展,并逐渐成为世界各国抢占的生物技术制高点。本文从转基因技术的内涵、国际转基因作物的研发态势、我国转基因作物的研发和产业化现状等方面进行阐述,探讨了大力发展转基因作物对于解决我国目前农业生产上面临的挑战、保障我国粮食安全和农业可持续发展的重要意义。     

A special issue on ＂Plant Molecular Biology＂

The use of molecular biology and genomics tools in plant biology research has greatly expanded our understandingof the molecular mechanisms that underlie plant development and physiology.The successful establishment of researchresources such as mutant populations has led to progress in a variety of fields,including plant reproductive develop-ment,signal transduction,hormone functions,defense responses and epigenetic control.In the future these advanceswill potentially facilitate crop improvement through molecular breeding.     

Plant nitrogen availability and crosstalk with phytohormones signallings and their biotechnology breeding application in crops

Nitrogen (N), one of the most important nutrients, limits plant growth and crop yields in sustainable agriculture system, in which phytohormones are known to play essential roles in N availability. Hence, it is not surprising that massive studies about the crosstalk between N and phytohormones have been constantly emerging. In this review, with the intellectual landscape of N and phytohormones crosstalk provided by the bibliometric analysis, we trace the research story of best-known crosstalk between N and various phytohormones over the last 20 years. Then, we discuss how N regulates various phytohormones biosynthesis and transport in plants. In reverse, we also summarize how phytohormones signallings modulate root system architecture (RSA) in response to N availability. Besides, we expand to outline how phytohormones signallings regulate uptake, transport, and assimilation of N in plants. Further, we conclude advanced biotechnology strategies, explain their application, and provide potential phytohormones-regulated N use efficiency (NUE) targets in crops. Collectively, this review provides not only a better understanding on the recent progress of crosstalk between N and phytohormones, but also targeted strategies for improvement of NUE to increase crop yields in future biotechnology breeding of crops.     

Advances in plant biotechnology and their implication for forestry research

Summary Over the past few years, techniques of cell biology, genetic screening, and gene manipulation have been developed to the extent that their impact on commercial development of improved plant varieties is predicted to have a measurable impact on agriculture by the year 2000 and beyond. A review will be given of progress that has been made in each of these areas toward the manipulation of crop plants for improved field performance and product quality. There are now several opportunities in which these techniques can be employed for the improvement of forestry species. In the light of the long-time scales involved in the generation of forestry products, it is important to focus on targets that are worthwhile pursuing commercially using appropriate technical routes. Selected examples will be given of the application of plant biotechnology techniques that promise potentially significant improvement for forestry species. Presented in the Keynote address Toward the Forest of Tomorrow at the 5th Meeting of the Conifer Biotechnology Working Group, Siltingbourne, England, July 8–13, 1990.     

Agricultural biotechnology for crop improvement in a variable climate: hope or hype?

Developing crops that are better adapted to abiotic stresses is important for food production in many parts of the world today. Anticipated changes in climate and its variability, particularly extreme temperatures and changes in rainfall, are expected to make crop improvement even more crucial for food production. Here, we review two key biotechnology approaches, molecular breeding and genetic engineering, and their integration with conventional breeding to develop crops that are more tolerant of abiotic stresses. In addition to a multidisciplinary approach, we also examine some constraints that need to be overcome to realize the full potential of agricultural biotechnology for sustainable crop production to meet the demands of a projected world population of nine billion in 2050.