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Title: Comparative effects of glyphosate and atrazine in chloroplast ultrastructure of wheat and downy brome. [Triticum aestivum; Bromus tectorum]

Abstract

Developing and mature leaves of winter wheat (Triticum aestivum L. var. Daws) and the weed species downy brome (Bromus tectorum L.) were subjected to 10 mM (foliar application) and 1 mM (root application) herbicide solutions. Glyphosate (N-(phosphonomethyl) glycine) and atrazine (2-chloro-4-(ethyl-amino)-6-(isopropylamino)-s-triazine) were prepared in a carrier composed of 5% soybean oil concentrate, 35% acetone and 60% water. Penetration experiments with /sup 3/H-labelled herbicides assessed what percentage of herbicide entered leaves, and microautoradiography was used to determine qualitatively how much herbicide was present in the sections viewed with TEM. Tissue was excised at 4, 18, 62 and 200 hours, and then either freeze-substituted or fixed chemically. Ultrastructural effects of each herbicide on chloroplasts from leaves of newly-germinated seedlings and of well-tillered plants are depicted and discussed. Temporal differences in response of chloroplasts to each herbicide are noted.

Authors:
; ; ;
Publication Date:
Research Org.:
Dept. of Agriculture-ARS, Pullman, WA
OSTI Identifier:
5897337
Report Number(s):
CONF-8707108-
Journal ID: CODEN: PPYSA; TRN: 87-037639
Resource Type:
Conference
Resource Relation:
Journal Name: Plant Physiol., Suppl.; (United States); Journal Volume: 83:4; Conference: Annual meeting of the American Society of Plant Physiologists, St. Louis, MO, USA, 19 Jul 1987
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; 60 APPLIED LIFE SCIENCES; HERBICIDES; ABSORPTION; BIOLOGICAL EFFECTS; AUTORADIOGRAPHY; CHLOROPLASTS; LEAVES; ROOT ABSORPTION; SEEDLINGS; TRACER TECHNIQUES; TRANSMISSION ELECTRON MICROSCOPY; TRITIUM COMPOUNDS; WEEDS; WHEAT; CELL CONSTITUENTS; CEREALS; ELECTRON MICROSCOPY; GRASS; ISOTOPE APPLICATIONS; LABELLED COMPOUNDS; MICROSCOPY; PESTICIDES; PLANTS; UPTAKE; 560300* - Chemicals Metabolism & Toxicology; 553006 - Agriculture & Food Technology- Other Agricultural Applications- (1987-)

Citation Formats

Auge, R.M., Gealy, D.R., Ogg, A.G., and Franceschi, V.R.. Comparative effects of glyphosate and atrazine in chloroplast ultrastructure of wheat and downy brome. [Triticum aestivum; Bromus tectorum]. United States: N. p., 1987. Web.
Auge, R.M., Gealy, D.R., Ogg, A.G., & Franceschi, V.R.. Comparative effects of glyphosate and atrazine in chloroplast ultrastructure of wheat and downy brome. [Triticum aestivum; Bromus tectorum]. United States.
Auge, R.M., Gealy, D.R., Ogg, A.G., and Franceschi, V.R.. Wed . "Comparative effects of glyphosate and atrazine in chloroplast ultrastructure of wheat and downy brome. [Triticum aestivum; Bromus tectorum]". United States. doi:.
@article{osti_5897337,
title = {Comparative effects of glyphosate and atrazine in chloroplast ultrastructure of wheat and downy brome. [Triticum aestivum; Bromus tectorum]},
author = {Auge, R.M. and Gealy, D.R. and Ogg, A.G. and Franceschi, V.R.},
abstractNote = {Developing and mature leaves of winter wheat (Triticum aestivum L. var. Daws) and the weed species downy brome (Bromus tectorum L.) were subjected to 10 mM (foliar application) and 1 mM (root application) herbicide solutions. Glyphosate (N-(phosphonomethyl) glycine) and atrazine (2-chloro-4-(ethyl-amino)-6-(isopropylamino)-s-triazine) were prepared in a carrier composed of 5% soybean oil concentrate, 35% acetone and 60% water. Penetration experiments with /sup 3/H-labelled herbicides assessed what percentage of herbicide entered leaves, and microautoradiography was used to determine qualitatively how much herbicide was present in the sections viewed with TEM. Tissue was excised at 4, 18, 62 and 200 hours, and then either freeze-substituted or fixed chemically. Ultrastructural effects of each herbicide on chloroplasts from leaves of newly-germinated seedlings and of well-tillered plants are depicted and discussed. Temporal differences in response of chloroplasts to each herbicide are noted.},
doi = {},
journal = {Plant Physiol., Suppl.; (United States)},
number = ,
volume = 83:4,
place = {United States},
year = {Wed Apr 01 00:00:00 EST 1987},
month = {Wed Apr 01 00:00:00 EST 1987}
}

Conference:
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  • The ability of downy brome to successfully infest crop lands is partially due to its prolific nature. To better understand its reproductive biology, studies investigating (1) effects of temperature and photoperiod on flowering, (2) prevention of downy brome seed information with herbicides, and (3) effects of drought on reproduction, were conducted. Seedling vernalization was more effective than seed vernalization in promoting downy brome flowering. Vernalizing imbibed downy brome caryopses at 3 C for 0 to 30 days did not induce rapid flowering. Downy brome seedlings were exposed to six photoperiod/temperature treatments. After transfer to long days, plants from the shortmore » da/3 C treatment flowered within 30 days. DPX-Y6202 and fluazifop-butyl were tested for their ability to prevent seed formation in downy brome. Fluazifop-butyl prevented seed formation over a wider range of application rates and growth stages than did DPX-Y6202. Seed production was prevented most readily by herbicide applications made early in the reproductive cycle. Translocation of radiolabel was greater with /sup 14/C-fluazifop-butyl than with /sup 14/C-DPX-Y6202, particularly into developing spikelets. Microautoradiographic techniques were used to identify mechanisms involved in the prevention of downy brome seed formation by these herbicides. Tissue localization of both herbicides was similar. The highest concentration of radiolabel was found in developing pollen grains, suggesting that the herbicides prevented seed formation by interrupting pollen development or function. Water stress reduced apparent photosynthesis and increased diffusive resistance of flag leaves.« less
  • A spring wheat cultivar (Triticum aestivum, cv. Albis) was field-grown near Bern (Switzerland) in open-top chambers or non-chambered plots and exposed to O/sub 3/ daily during the growing period to study effects on physiological parameters associated with senescence of flag leaves. Seasonal 8-hr/d mean O/sub 3/-concentration used were 0.020 (charcoal-filtered, F), 0.035 (non-filtered, NF) and 0.103 ..mu..1/1 (O/sub 3/ added from 9am to 5pm, NF+O/sub 3/) inside, and 0.038 ..mu..1/1 outside the chambers. In leaves exposed to NF+O/sub 3/ chlorophyll loss started 10 d before anthesis and was more rapid than in leaves treated with F or NF. Adaxial andmore » abaxial stomatal conductances were highest in the NF treatment, and about 15% and 80% lower in F and NF+O/sub 3/, respectively. Synthesis of ethylene and 1-aminocyclopropane-1-carboxylic acid (free and conjugated ACC) was stimulated in the F and NF treatment between 10 and 20 d after anthesis. Exposure to NF+O/sub 3/ led to strong inhibition of ethylene and ACC synthesis after anthesis. The results suggest that ambient levels of O/sub 3/ at this site have little effect on these parameters, but that chronic exposure to elevated O/sub 3/ levels is inhibitory to senescence processes of flag leaves, e.g. synthesis of ACC and ethylene.« less
  • Cell and chloroplast development were characterized in young Triticum aestivum cv Hereward leaves grown at ambient (350 {mu}L L{sup {minus}1}) or at elevated (650 {mu}L L{sup {minus}1}) CO{sub 2}. In elevated CO{sub 2}, cell and chloroplast expansion was accelerated by 10 and 25%, respectively, in the first leaf of 7-d-old wheat plants without disruption to the leaf developmental pattern. Elevated CO{sub 2} did not affect the number of chloroplasts in relation to mesophyll cell size or the linear relationship between chloroplast number or size and mesophyll cell size. No major changes in leaf anatomy or in chloroplast ultrastructure were detectedmore » as a result of growth in elevated CO{sub 2}, but there was a marked reduction in starch accumulation. In leaf sections fluorescently tagged antisera were used to visualize and quantitate the amount of cytochrome f, the {alpha}- and {beta}-subunits of the coupling factor 1 in ATP synthase, D1 protein of the photosystem II reaction center, the 33-kD protein of the extrinsic oxygen-evolving complex, subunit II of photosystem I, and ribulose-1,5-biphosphate carboxylase/oxygenase. A significant finding was that in 10 to 20% of the mesophyll cells grown in elevated CO{sub 2} the 33-kD protein of the extrinsic oxygen-evolving complex of photosystem II and cytochrome f were deficient by 75%, but the other proteins accumulated normally. 29 refs., 6 figs., 2 tabs.« less
  • Two cultivars of wheat (Triticum aestivum L. cvs Sonoita and Yecoro Rojo) were grown to maturity in a Phytotron B chamber within four sub-chambers which imposed two CO/sub 2/ levels (350 or 1000 ppm) at either ambient (21%) or low oxygen (5%). Techniques of growth analysis were used to characterize changes in plant carbon budgets imposed by the gas regimes. Large increases in leaf area were seen in the low oxygen treatments, due primarily to a stimulation of tillering. No necrosis was observed in roots developing at 5% oxygen but rather root development increased dramatically. Flowering was much delayed inmore » the low oxygen, 350 ppm carbon dioxide regime and the spikes which did develop did not mature. While one cultivar (Sonoita) did not respond to CO/sub 2/ enrichment (1000 ppm) at ambient oxygen in terms of increases in leaf area and head number, carbon dioxide enrichment overcame the low oxygen effect on flowering in both cultivars. The results demonstrate a previously unknown interaction between carbon dioxide enrichment and low oxygen as they affect reproduction and may help elucidate the nature of low-oxygen-induced infertility.« less