Grafting has been used in agriculture for over 2000 years. Disease resistance and environmental tolerance are highly beneficial traits that can be provided through use of grafting, although the mechanisms, in particular for resistance, have frequently been unknown. As information emerges that describes plant disease resistance mechanisms, the proteins, and nucleic acids that play a critical role in disease management can be expressed in genetically engineered (GE) plant lines. Utilizing transgrafting, the combination of a GE rootstock with a wild-type (WT) scion, or the reverse, has the potential to provide pest and pathogen resistance, impart biotic and abiotic stress tolerance, or increase plant vigor and productivity. Of central importance to these potential benefits is the question of to what extent nucleic acids and proteins are transmitted across a graft junction and whether the movement of these molecules will affect the efficacy of the transgrafting approach. Using a variety of specific examples, this review will report on the movement of organellar DNA, RNAs, and proteins across graft unions. Attention will be specifically drawn to the use of small RNAs and gene silencing within transgrafted plants, with a particular focus on pathogen resistance. The use of GE rootstocks or scions has the potential to extend the horticultural utility of grafting by combining this ancient technique with the molecular strategies of the modern era.

FtsZ1 and FtsZ2 are phylogenetically distinct homologues of the tubulin-like bacterial cell division protein FtsZ that play major roles in the initiation and progression of plastid division in plant cells. Both proteins are components of a mid-plastid ring, the Z-ring, which functions as a contractile ring on the stromal surface of the chloroplast IEM (inner envelope membrane). FtsZ1 and FtsZ2 have been shown to interact, but their in vivo biochemical properties are largely unknown. To gain insight into the in vivo biochemical relationship between FtsZ1 and FtsZ2, in the present study we investigated their molecular levels in wild-type Arabidopsis thaliana plants and endogenous interactions in Arabidopsis and pea. Quantitative immunoblotting and morphometric analysis showed that the average total FtsZ concentration in chloroplasts of 3-week-old Arabidopsis plants is comparable with that in Escherichia coli. FtsZ levels declined as plants matured, but the molar ratio between FtsZ1 and FtsZ2 remained constant at approx. 1:2, suggesting that this stoichiometry is regulated and functionally important. Density-gradient centrifugation, native gel electrophoresis, gel filtration and co-immunoprecipitation experiments showed that a portion of the FtsZ1 and FtsZ2 in Arabidopsis and pea chloroplasts is stably associated in a complex of approximately 200-245 kDa. This complex also contains the FtsZ2-interacting protein ARC6 (accumulation and replicatioin of chloroplasts 6), an IEM protein, and analysis of density-gradient fractions suggests the presence of the FtsZ1-interacting protein ARC3. Based on the mid-plastid localization of ARC6 and ARC3 and their postulated roles in promoting and inhibiting chloroplast FtsZ polymer formation respectively, we hypothesize that the FtsZ1-FtsZ2-ARC3-ARC6 complex represents an unpolymerized IEM-associated pool of FtsZ that contributes to the dynamic regulation of Z-ring assembly and remodelling at the plastid division site in vivo.

Vitamin C (l-ascorbate, AsA) is an essential nutrient required in key metabolic functions in humans and must be obtained from the diet, mainly from fruits and vegetables. Given its importance in human health and plant physiology we sought to examine the role of the ascorbate recycling enzymes monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) in tomato (Solanum lycopersicum), an economically important fruit crop. Cytosolic-targeted tomato genes Mdhar and Dhar were cloned and over-expressed under a constitutive promoter in tomato var. Micro-Tom. Lines with increased protein levels and enzymatic activity were identified and examined. Mature green and red ripe fruit from DHAR over-expressing lines had a 1.6 fold increase in AsA content in plants grown under relatively low light conditions (150 µmol m−2 s−1). Conversely, MDHAR over-expressers had significantly reduced AsA levels in mature green fruits by 0.7 fold. Neither over-expressing line had altered levels of AsA in foliar tissues. These results underscore a complex regulation of the AsA pool size in tomato.

Agricultural biotechnology and, specifically, the development of genetically modified (GM) crops have been controversial for several reasons, including concerns that the technology poses potential negative environmental or health effects, that the technology would lead to the (further) corporatization of agriculture, and that it is simply unethical to manipulate life in the laboratory. GM crops have been part of the agricultural landscape for more than 15 years and have now been adopted on more than 170 million hectares (ha) in both developed countries (48%) and developing countries (52%). On the basis of this substantial history and data spanning many years, the economic and environmental impacts of GM crops can now be summarized with some certainty, and the analysis indicates that, on balance, many benefits have accrued from the adoption of GM crops. There continue to be many ethical issues that are being debated, and many are being resolved through institutional interventions. The future of agricultural productivity would be better served if the genetic modification debate were less polarized and were focused on the potential for complementarity of GM technologies within a diversified farming system framework.

This Federal Register notice announces the policy of the federal agencies involved with the review of biotechnology research and products. As certain concepts are new to this policy, and will be the subject of rulemaking, the public is invited to comment on these aspects which are specifically identified herein. DATE: Comments must be received on or before August 25, 1986. Public Participation: The Domestic Policy Council Working Group on Biotechnology through the Office of Science and Technology Policy is seeking advice on certain refinements published herein to the previously published proposed coordinated framework for regulation of biotechnology. These new aspects include the Biotechnology Science Coordinating Committee's (BSCC's) definitions for an "ontogenetic organism (new organism)" and for "pathogen." These definitions are critical to the coordinated framework for the regulation of biotechnology because they establish the types of the organisms subject to certain kinds of review. The interagency coordination mechanism, the Biotechnology Science Coordinating Committee (BSCC), discussed in more detail in section C, of this Preamble, came into being while the agencies were still in process of refining their regulatory proposals. Consequently, the BSCC was able to play a helpful role in the formulation of two basic principles: (1) Agencies should seek to adopt consistent definitions of those genetically engineered organisms subject to review to the extent permitted by their respective statutory authorities; and, (2) agencies should utilize scientific reviews of comparable rigor. The regulatory framework anticipates that future scientific developments will lead to further refinements. Experience with earlier basic scientific research has shown that as the science progressed and became better understood by the public, regulatory regimens could be modified to reflect more complete understanding of the potential risks involved. Similar evolution is anticipated in the regulation of commercial products as scientists and regulators learn to predict more precisely particular product use that require greater or lesser controls or even exemption from any federal review. This framework has sought to distinguish between those organisms that require a certain level of federal review and those that do not. This follows a traditional approach to regulation. Within agriculture, for example, introductions of new plants, animals and microorganisms have long occurred routinely with only some of those that are not native or are pathogenic requiring regulatory approval. It should be noted that microorganisms play many essential and varied roles in agriculture and the environment and that for decades agricultural scientists have endeavored to exploit their advantages through routine experimentation and introduction into the environment; and as a rule these agricultural and environmental introductions have taken place without harm to the environment. B. The Coordinated Framework for the Regulation of Biotechnology General Comments...

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SummaryThe Public Intellectual Property Resource for Agriculture (PIPRA) was founded in 2004 by the Rockefeller Foundation in response to concerns that public investments in agricultural biotechnology benefiting developing countries were facing delays, high transaction costs and lack of access to important technologies due to intellectual property right (IPR) issues. From its inception, PIPRA has worked broadly to support a wide range of research in the public sector, in specialty and minor acreage crops as well as crops important to food security in developing countries. In this paper, we review PIPRA's work, discussing the failures, successes, and lessons learned during its years of operation. To address public sector's limited freedom-to-operate, or legal access to third-party rights, in the area of plant transformation, we describe PIPRA's patent 'pool' approach to develop open-access technologies for plant transformation which consolidate patent and tangible property rights in marker-free vector systems. The plant transformation system has been licensed and deployed for both commercial and humanitarian applications in the United States (US) and Africa, respectively.