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There is an increasing demand for fresh fruits such as strawberry enriched in antioxidants and vitamins. Strawberry fruit quality is highly affected by genotype and environmental conditions. In thi...

Propagation of vegetative cuttings is the most efficient and cost-effective method for producing homogeneous horticultural plants and forest trees when apomictic seed is unavailable. This method depends on the formation of adventitious roots (ARs) in stem or leaf cuttings. Improved understanding of the molecular mechanisms that regulate AR development could enhance the application of this technique. In this article, we review the physiological and developmental processes that regulate AR formation. We map gene function in lateral root development to transcriptomic analyses of the stages of AR formation to reveal potential gene function controlling this important process. We then synthesize a model of the regulatory network controlling AR formation that includes the unique aspects of AR formation in woody plants. Finally, we provide a perspective and suggest future directions for elucidation of molecular processes that regulate AR development.

The Earth has been undergoing climatic changes for centuries, driven by increasing concentration of atmospheric carbon dioxide (CO2). The atmospheric CO2 concentration has been predicted to reach 550–750 μmol mol−1 by 2050, or twice as high as the current level. Much of the research in the last 20–30 years concerning elevated CO2 (eCO2) has been about how plants would respond to the eCO2 at physiological levels. As eCO2 can lead to more frequent drought or extreme high or low temperature, increasingly more research has focused on the interactions between eCO2 and other abiotic stresses. How stresses may affect plant growth and development and productivity, as well as how agricultural practices may be altered to cope with these changes must be determined. These concerns have been the subject of numerous reviews. However, it is only in the last several years that data at the “omics” levels has been available to explore how necessary physiological changes may be brought about in a future complex environment....

With predicted global changes in temperature and precipitation, drought will increasingly impose a challenge to biomass production. Most of the bioenergy crops have some degree of drought susceptibility as revealed for example through measures of low water-use efficiency (WUE). It is imperative to improve drought tolerance and WUE in bioenergy crops for sustainable biomass production in arid and semi-arid regions. Genetics and functional genomics can play critical roles in generating knowledge to inform and aid genetic improvement for drought tolerance in bioenergy crops. The molecular aspects of drought response have been extensively investigated in model plants like Arabidopsis, yet our understanding of the molecular mechanisms underlying drought tolerance in bioenergy crops is limited. Plants in general exhibit various responses to drought stress depending on species and genotype. A rational strategy for studying drought tolerance in bioenergy crops is to translate the knowledge from model plants relat...

Apple is one of the most cultivated tree fruits worldwide, and is susceptible to many diseases. Understanding the interactions between the host and pathogen is critical in implementing disease management strategies and developing resistant cultivars. This review provides an update on the interactions of apple with Alternaria alternata apple pathotype, which causes Alternaria blotch, with a brief history about the discovery of the disease and pathogen and its damage and epidemiology. The focus of the review is placed on the physiological and genetic response of the host to pathogen infection, including resistance and susceptibility, and the molecular markers associated with them. Of the response of the pathogen to the host, the emphasis is placed on the role of the selective toxins on pathogenicity and their genetic controls and regulations. The review ends with a perspective on future directions in the research on the apple-A. alternata pathosystem in the era of genomics and post genomics, particularly on...

Species within the genus Populus are among the fastest growing trees in regions with a temperate climate. Not only are they an integral component of ecosystems, but they are also grown commercially for fuel, fiber, and forest products in rural areas of the world. In the late 1970s, they were designated as a bioenergy crop by the U.S. Department of Energy, as a result of research following the oil embargo. Populus species also serve as model trees for plant molecular biology research. In this article, we will review recent progress in the genetic improvement of Populus, considering both classical breeding and genetic engineering for bioenergy, as well as in using transgenics to elucidate gene functionality. A perspective for future improvement of Populus via functional genomics will also be presented.

Recent advances in Populus genomics have greatly expanded its popularity as a reference for fundamental as well as applied research in woody plants. In this review, we provide an overview of the state-of-the-science in Populus genomics research, including experimental and computational genomics. We have surveyed and summarized the following: 1) pioneering as well as more recent reports of genetics- and genomics-based investigations in Populus, 2) the positive impact of technological improvements, 3) findings from phylogenetic analyses of gene families, and 4) genomic databases. In the area of Populus experimental genomics, genetic approaches have been advanced to the genome scale with resolution to the gene and/or single nucleotide level. On the other hand, the modern “omics” approaches have been successfully applied to analysis of gene function, such as transcriptome profiling using microarrays as well as the next-generation DNA sequencing technology, and characterization of proteome and metabolome using...

Invasive plants, one of the most devastating ecological problems in the 21st century, cause an estimated $35 billion loss per year to the economy in the United States alone. More than 50% of all invasive plant species and 85% of invasive woody plant species were introduced originally for ornamental and landscape use. Because many non-native ornamentals are commercially important and widely utilized for various purposes, completely banning their use and prohibiting their import are unpractical solutions. On the other hand, currently used methods to control the spread of non-native plants are ineffective, expensive, or environmentally problematic. Recent advances in plant molecular biology and plant genetic transformation may enable us to create sterile cultivars of these non-native ornamental crops of high commercial value. The use of sterile cultivars should reduce or eliminate the undesirable spread of some non-native invasive plants into natural areas.

Vegetative propagation by cuttings is critical to the horticultural industry, particularly the ornamental and fruit sections. This article briefly reviews the traditional approaches to improve root formation, specifically with hardwood cuttings. The focus of this review has been placed on the nontraditional strategies, including infection with Agrobacterium rhizogenes and genetic engineering with rol genes, or ro/B gene alone from A. rhizogenes and iaaM gene from auxin biosynthesis genes (iaaM, iaaH) from A. tumefaciens. Recent results with these new strategies have shown great potential in enhancing adventitious root formation in difficult-to-root woody species. The future perspective in understanding adventitious rooting mechanisms and new strategies for improving rooting are also discussed.

The spread of invasive plants is one of the most challenging ecological problems in the 21st Century, causing a $35 billion loss per year to the economy in the United States alone. More than 50% of all invasive plants and 85% of invasive woody species were introduced originally for ornamental and landscape use. Because many nonnative plants are commercially important and widely utilized for various purposes, completely banning their use and prohibiting their imports are unpractical solutions for control. On the other hand, the methods currently used to control the spread of nonnative plants are ineffective, expensive, or environmentally problematic. Recent advances in plant biotechnology may enable us to create sterile cultivars of these nonnative ornamental crops of commercial value. The use of sterile cultivars should reduce or eliminate the undesirable spread of some nonnative invasive plants into natural areas.

Plants, once germinated or transplanted, will live and die in the same location their entire life. And for woody perennial plants, this circumstance exists for many years, even millennia. As a resu...