Agnet Dec. 2/03 -- III
Chlorophyll
breakdown: Pheophorbide a oxygenase is a Rieske-type iron-sulfur protein,
encoded by the accelerated cell death 1 gene
Relative
fitness of glyphosate resistant creeping bentgrass cultivars in Kentucky
bluegrass
Successful
BIO-Europe 2003 reflects the upturn of the biotechnology industry
EPA extends
public comment period regarding voluntary cancellation request for certain
creosote and acid copper chromate uses
Office of
pesticide programs encourages use of electronic OCED formats for new submissions
Damaging
pine pest in scientists' sights
Helping
spuds help themselves: Boosting potatoes' natural ability to protect themselves
Light- and
pH-dependent structural changes in the PsbS subunit of photosystem II
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Chlorophyll
breakdown: Pheophorbide a oxygenase is a Rieske-type iron-sulfur protein,
encoded by the accelerated cell death 1 gene
December 1, 2003
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.2036571100
Adriana Pruinská *, Gaby Tanner *, Iwona Anders *, Maria Roca , and Stefan Hörtensteiner
*
*Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013
Bern, Switzerland; and Plant Genetics and Breeding Department, Institute of
Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, Ceredigion
SY23 3EB, United Kingdom
Communicated by J. Clark Lagarias, University of California, Davis, CA, October
10, 2003 (received for review August 27, 2003)
http://www.pnas.org/cgi/content/abstract/2036571100v1
Chlorophyll (chl) breakdown during senescence is an integral part of plant
development and leads to the accumulation of colorless catabolites. The loss of
green pigment is due to an oxygenolytic opening of the porphyrin macrocycle of
pheophorbide (pheide) a followed by a reduction to yield a fluorescent chl
catabolite. This step is comprised of the interaction of two enzymes, pheide a
oxygenase (PaO) and red chl catabolite reductase. PaO activity is found only
during senescence, hence PaO seems to be a key regulator of chl catabolism.
Whereas red chl catabolite reductase has been cloned, the nature of PaO has
remained elusive. Here we report on the identification of the PaO gene of
Arabidopsis thaliana (AtPaO). AtPaO is a Rieske-type iron-sulfur
cluster-containing enzyme that is identical to Arabidopsis accelerated cell
death 1 and homologous to lethal leaf spot 1 (LLS1) of maize. Biochemical
properties of recombinant AtPaO were identical to PaO isolated from a natural
source. Production of fluorescent chl catabolite-1 required ferredoxin as an
electron source and both substrates, pheide a and molecular oxygen. By using a
maize lls1 mutant, the in vivo function of PaO, i.e., degradation of pheide a
during senescence, could be confirmed. Thus, lls1 leaves stayed green during
dark incubation and accumulated pheide a that caused a light-dependent lesion
mimic phenotype. Whereas proteins were degraded similarly in wild type and lls1,
a chl-binding protein was selectively retained in the mutant. PaO expression
correlated positively with senescence, but the enzyme appeared to be
posttranslationally regulated as well.
Relative
fitness of glyphosate resistant creeping bentgrass cultivars in Kentucky
bluegrass
December 2003
ISB News Report
David S. Gardner and T. Karl Danneberger
http://www.isb.vt.edu/news/2003/news03.dec.html#dec0303
Creeping bentgrass is a widely used turfgrass species on golf course greens,
tees, and fairways in the northern United States. A disadvantage of creeping
bentgrass is its vulnerability to a wide range of pest problems. Annual
bluegrass is a serious weedy grass problem on creeping bentgrass putting
greens1. No herbicide chemistry is available to control, effectively and
selectively, annual bluegrass in creeping bentgrass.
Glyphosate, the active ingredient in Roundup® brand herbicides is a broad
spectrum herbicide that is toxic to plants, fungi, and bacteria2. Glyphosate
resistant crops have been developed by genetically engineering plants with a
gene that codes for an EPSP synthase protein with lower sensitivity to
glyphosate3. The Monsanto and Scotts Companies have collaborated in the
development of genetically engineered creeping bentgrass cultivars that are
resistant to glyphosate via the heterologous expression of a gene from the CP4
strain of Agrobacterium sp. encoding for a glyphosate resistant form of EPSP.
Adoption of glyphosate resistant creeping bentgrass could potentially simplify
and improve control of a wide array of invasive annual, biennial, and perennial
grass, broadleaf, and sedge species that can invade golf turf. The availability
of glyphosate as an over-the-top treatment on glyphosate resistant creeping
bentgrass could significantly reduce the need for many of these herbicides,
resulting in several important environmental, health, and safety benefits. It is
less likely to leach than most other turf herbicides. It has low toxicity to
mammals, birds, and fish, and it is one of the few commercially available
herbicides classified as "Category E" by the EPA (evidence of non-carcinogenicity
for humans) 4.
Concern over the release of transgenic varieties has arisen specifically with
the competitive ability of transformed varieties. Therefore, this study was
performed to determine whether the relative competitive growth of several
glyphosate resistant creeping bentgrass lines is equivalent to traditional
creeping bentgrass when transplanted into a mature and competing turf stand.
A field study was initiated on June 23, 2000, in Marysville, OH. Companion
studies were also conducted in New Jersey and Oregon. The Kentucky bluegrass
turf area was maintained for uniform turf coverage and surface drainage. Soil
cores (35 mm in diameter and 60 mm deep) were removed from the original turf
area on 60-90 cm centers with an auger bit. Bentgrass plugs were transplanted
directly into the core holes so that the crowns of the plant were at or slightly
below the soil surface and so that firm contact between the Jiffy pot media was
maintained with the field soil. The turf area was maintained under a regime
appropriate for the original dominant species following an initial establishment
phase to acclimate the bentgrass transplants. Bentgrass plant diameter was
measured in centimeters during the first week of each month of the growing
season. Mean plant diameter was calculated as an average of two perpendicular
measurements made on each tiller plot.
Growth of all the creeping bentgrass cultivars and lines was significantly
greater in Oregon as compared to New Jersey and Ohio (analysis not shown). The
increased growth recorded in Oregon may have been due to more favorable growing
conditions in Oregon, such as the Mediterranean climate and extended frost-free
period. Additionally, in Oregon the height of cut was ½ inch and bentgrass is
more tolerant of low clipping heights than either the Kentucky bluegrass or
perennial ryegrass turf. In both New Jersey and Ohio, the higher height of cut
may have favored the bluegrass over creeping bentgrass entries. Other factors
may also have contributed to the differences between locations, including soil
type and cultivars or species composition in the test plot.
At all locations, no differences between the reference, non-transformed, or
transformed lines were observed when monitoring disease incidence, insect
susceptibility, presence or absence of beneficial organisms, plant growth
characteristics, or aggressiveness characteristics on any date. No statistically
significant differences in growth were observed for any date at the Marysville,
Ohio, location (Table 2). The density of the Kentucky bluegrass stand as well as
competition from broadleaf weeds, such as dandelion and white clover, resulted
in more variation among replications of the same cultivar or line than were
observed between cultivars and lines.
ASR 368, ASR 333 and ASR 365 were all statistically equivalent to their
non-transformed parents and to commercial cultivars throughout the study period.
Transgenic creeping bentgrass lines that are resistant to glyphosate displayed
no additional increase in vegetative growth or relative fitness compared to
traditional non-transgenic creeping bentgrass when competing with other species
such as Kentucky bluegrass and perennial ryegrass maintained as turfgrass. The
results from three diverse environments (New Jersey, Oregon, and Ohio) indicate
that the expression of the gene for glyphosate tolerance conferred no
competitive advantage compared to non-transgenic creeping bentgrasses. These
results indicate that the relative fitness of transgenic lines of creeping
bentgrass is within the normal range of values for other commercially available
cultivars. Therefore, these transgenic lines would not be expected to have a
competitive advantage in vegetative growth over non-transformed creeping
bentgrass in either managed or unmanaged ecosystems. The variability in creeping
bentgrass growth observed in this study is less than that typically observed due
to differences in climate and cultural practices, such as mowing, irrigation,
and fertilization.
The results of this, and many other studies, are part of a petition that was
submitted to APHIS for review to deregulate Roundup Ready creeping bentgrass and
make it commercially available. The review process is quite lengthy and can take
18 months or longer to complete. If the review is favorable, Roundup Ready
Creeping Bentgrass could appear on the market sometime in late 2004 or 2005.
References
1. Turgeon AJ. (2002) Turfgrass Management. Prentice Hall, Inc. Englewood
Cliffs, NJ.
2. Gresshoff PM. (1979) Growth inhibition of glyphosate and reversal of its
action by phenylalanine and tyrosine. Aust. J. Plant Physiol. 6: 177-185.
3. Thompson GA et al. (1987) Expression in plants of a bacterial gene coding for
glyphosate resistance. Weed Sci. 35(1): 19-23.
4. Gustafson DI. (1989) Groundwater ubiquity score: a simple method for
assessing pesticide leachability. Environ. Toxic. and Chem. 8: 339-357.
David S. Gardner and T. Karl Danneberger
Department of Horticulture and Crop Science
The Ohio State University, Columbus, OH
gardner.254@osu.edu
Successful
BIO-Europe 2003 reflects the upturn of the biotechnology industry
November 17-19, 2003
Congress Center/Maritim Hotel, Frankfurt, Germany
WASHINGTON, DC and CARLSBAD, CA - This year's BIO-Europe 2003 9th Annual
International Partnering Conference set new standards and remains the undisputed
champion in the biotech partnering arena. Despite a still recovering biotech
industry, BIO-Europe 2003 attracted more than 1,200 attendees, again a
significant increase from last year. With over 3,300 individual partnering
meetings and 200 company presentations the event cemented its position as the
largest partnering meeting in the biotech and biopharmaceutical industry.
"Boehringer Ingelheim has been part of BIO-Europe since its very first
event eight years ago. It is truly an unprecedented platform for initiating
biotech partnerships and co-operations. Once again, the event met all our
expectations," said Jonathan Turner, Head of Business Development at
Boehringer Ingelheim GmbH.
"The presence of not only a huge number of biotech companies from all
around the world but also the high number of mid- and big sized pharma companies
was impressive and of enormous importance for us," added Mary Callan, VP of
Business Development at Morphotek. "We consider attendance at BIO-Europe an
absolute 'must'."
BIO-Europe along with BioSquare, which is held annually in the spring, are the
two key partnering conferences in Europe hosted by the Biotechnology Industry
Organization together with the E.B.D. Group. BioSquare 2004 will take place in
Basel, Switzerland, March 10 - 12, 2004, and will also be co-hosted by Biovision,
EuropaBio & the JBA.
EPA
extends public comment period regarding voluntary cancellation request for
certain creosote and acid copper chromate uses
December 1, 2003
US Environmental Protection Agency
http://www.epa.gov/oppfead1/cb/csb_page/updates/croesote-cca.htm
On September 29, 2003, EPA issued a notice of receipt of requests by creosote
and acid copper chromate registrants to voluntarily cancel certain pesticide
registrations and/or to amend to terminate certain uses of affected products.
Public comments in response to the voluntary cancellation request were due by
October 29, 2003. However, based on comments received, the Agency published a
notice in the November 26, 2003, Federal Register, extending the public comment
period to December 26, 2003. The Federal Register Notice can be found at
www.epa.gov/fedrgstr.
Office
of pesticide programs encourages use of electronic OCED formats for new
submissions
December 1, 2003
US Environmental Protection Agency
http://www.epa.gov/oppfead1/eds/oecdformatting.htm
The Office of Pesticide Programs (OPP) announces that it encourages registrants
to submit registration applications for new active ingredients of agricultural
pesticides (conventional, biochemical, or microbial) in electronic and “OECD
dossier” format. OPP also encourages registrants to submit any large volume(s)
of data in electronic format even if the dossier format is not used. Based on
experience with receipt and use of electronic and dossier submissions, OPP
believes there are significant efficiencies to the Program and to
registrants--reduced regulatory burdens to registrants making multinational data
submissions and review efficiencies to OPP staff evaluating these data
submissions.
OPP and regulatory agencies from member countries of the Organization for
Economic Cooperation and Development (OECD) have collaborated to harmonize many
of the processes and requirements of pesticide registration for the purpose of
greater efficiencies for industry and pesticide regulatory agencies. One of the
products of this collaboration is the standardized format for the compilation,
presentation, and content of the supporting data and information for an
application for registration of a new active ingredient for agricultural
pesticides. A dossier includes the necessary application forms, summaries of the
submitted studies and proposed use patterns, assessments of science disciplines,
and an overall risk assessment and proposed risk mitigation measures, as well as
the individual study reports. Regulatory agencies of a number of OECD countries,
including Canada, are accepting submissions in dossier format. Guidance for
preparing an application in OECD dossier format and OPP’s guidance for filing
electronic data submissions are available on the Web sites below.
OECD member countries are also developing guidance for preparing dossiers
specifically for pheromone and microbial pesticides. Until that guidance is
completed, registrants of these pesticides may choose to use the current
guidance. An OECD dossier for antimicrobial pesticides has not yet been
developed as harmonization efforts are currently focused on data requirements
and protocols for key studies. Also, OPP and Canada’s Pest Management
Regulatory Agency are collaborating to further harmonize the process for
assembling electronic submissions in dossier format. OPP will provide updates on
these projects in the future.
OPP encourages registrants to use electronic submissions of dossiers or any
studies with or without an OECD dossier in accordance with the following
guidance. Registrants who file electronic submissions should consult OPP’s
electronic submission guidance website at http://www.epa.gov/oppfead1/eds/edsgoals.htm.
OECD’s dossier guidance is available at
http://www.oecd.org/document/48/0,2340,en_2649_201185_2085104_1_1_1_1,00.html.
For questions about electronic submissions, contact Ms. Teresa Downs at
703/305-5363 or downs.teresa@epa.gov or Mr. Robert Schultz at 703/308-8186 or
schultz.robert@epa.gov.
Damaging
pine pest in scientists' sights
December 2, 2003
Australia CSRIO
Press Release, Ref 2003/2000
http://www.csiro.au/index.asp?type=mediaRelease&id=Praphid
CSIRO is a key player in a plan to control a tiny insect suspected of inflicting
losses of up to $24 million a year on the Australian forestry industry.
After it was first detected in the ACT in 1998 the Monterey pine aphid (Essigella
californica) took just two years to spread throughout Australia's major radiata
pine growing areas.
"Since the aphid appeared in parts of NSW, Victoria and South Australia,
severe and recurring defoliation of pine plantations has occurred," Dr
Barrie May of CSIRO Forestry and Forest Products says
"While no such result was reported in other states where the aphid has been
found, detailed assessments of its effect on experimental stands in the 'Green
Triangle' (a major pine growing region across SE SA and SW Victoria) and NE
Victoria show it has caused significant reductions in tree growth and that its
impact is not diminishing over time."
The first stage of the project is designed to establish beyond any doubt that
the Monterey pine aphid is responsible for the defoliation effect.
Over the next 13 months research to establish a more precise estimate of the
total losses involved will also be undertaken.
"This will provide a sound economic and scientific basis for a proposed
follow-up project which will evaluate the potential stand management, tree
breeding and biocontrol strategies required to manage a potentially serious
threat to Australia's pine timber industry," Dr May says.
CSIRO Forestry and Forest Products and its funding partner in the project - the
Forest and Wood Products Research and Development Corporation (FWPRDC - project
code number PN04.4002 ) - have enlisted the support of plantation growers,
research agencies and chemical manufacturers.
Other collaborators contributing to the project include; Auspine Ltd, Bayer
Environmental Science, Forest Science Centre, Forestry SA, and Green Triangle
Forest Products, Hancock Victorian Plantations and NSW State Forests.
Helping
spuds help themselves: Boosting potatoes' natural ability to protect themselves
December 2, 2003
ARS News Service
Agricultural Research Service, USDA
Jan Suszkiw
Potato and other plants have the means to defend themselves from hungry insects
and microbes that cause disease. But some plants don't mobilize these defenses
in time to do much good. Now, Agricultural Research Service scientists are
testing a way to snap such sluggish plants to attention and steel them for
battle.
In studies at Prosser, Wash., the scientists are spraying the plants with
salicylic acid, a substance familiar to many as an ingredient in aspirin. In
plants, it functions as a natural signaling compound that triggers a protective
response called "systemic acquired resistance," or SAR.
Plant scientists have known about SAR for years, but only recently have SAR-activating
products become available for use on crops including tomatoes, lettuce and
spinach. Healthier plants and reduced pesticide use are among the benefits
associated with activating SAR.
But according to Roy Navarre, a molecular biologist at the ARS Vegetable and
Forage Crops Research Unit in Prosser, little is known about such benefits in
potatoes, a crop that generates nearly $3 billion annually in U.S. farmgate
sales.
So, earlier this year, he and colleagues kicked off a project to find out.
Through lab and field studies, their objective is to determine which SAR
activators work best, in what parts of the potato plant, for how long, and at
what doses.
Scientists also test the activated plants' SAR defenses by inoculating the
plants with organisms such as late blight fungus, white mold, potato virus Y,
green peach aphid and Columbia root-knot nematode. Chemical fumigants are a
staple defense against the latter pest, but pumping them into the soil can cost
farmers $250 an acre.
Navarre is encouraged by the studies' early results, especially against
viruses, for which there is no direct method of control. Read more about
this research in this month's issue of Agricultural Research magazine,
available on the World Wide Web at:
http://www.ars.usda.gov/is/AR/archive/dec03/plant1203.htm
ARS is the U.S. Department of Agriculture's chief scientific research agency.
Light-
and pH-dependent structural changes in the PsbS subunit of photosystem II
December 1, 2003
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.2533072100
Elisabetta Bergantino, Anna Segalla, Alessia Brunetta, Enrico Teardo, Fernanda
Rigoni, Giorgio Mario Giacometti *, and Ildikò Szabò *
Department of Biology, University of Padua, Viale G. Colombo 3, 35121 Padua,
Italy
Edited by George H. Lorimer, University of Maryland, College Park, MD, and
approved October 15, 2003 (received for review May 21, 2003)
http://www.pnas.org/cgi/content/abstract/2533072100v1
In higher plants, the PsbS subunit of photosystem II (PSII) plays a crucial role
in pH- and xanthophyll-dependent nonphotochemical quenching of excess absorbed
light energy, thus contributing to the defense mechanism against photoinhibition.
We determined the amino acid sequence of Zea mays PsbS and produced an antibody
that recognizes with high specificity a region of the protein located in the
stroma-exposed loop between the second and third putative helices. By means of
this antiserum, the thylakoid membranes of various higher plant species revealed
the presence of a 42-kDa protein band, indicating the formation of a dimer of
the 21-kDa PsbS protein. Crosslinking experiments and immunoblotting with other
antisera seem to exclude the formation of a heterodimer with other PSII protein
components. The PsbS monomer/dimer ratio in isolated thylakoid membranes was
found to vary with luminal pH in a reversible manner, the monomer being the
prevalent form at acidic and the dimer at alkaline pH. In intact chloroplasts
and whole plants, dimer-to-monomer conversion is reversibly induced by light,
known to cause luminal acidification. Sucrose-gradient centrifugation revealed a
prevalent association of the PsbS monomer and dimer with light-harvesting
complex and PSII core complexes, respectively. The finding of the existence of a
light-induced change in the quaternary structure of the PsbS subunit may
contribute to understanding the mechanism of PsbS action during nonphotochemical
quenching.
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