Roger J. Sauve

Proteome changes induced by aluminium stress in tomato roots

Growth inhibition in acid soils due to Al stress affects crop production worldwide. To understand mechanisms in sensitive crops that are affected by Al stress, a proteomic analysis of primary tomato root tissue, grown in Al-amended and non-amended liquid cultures, was performed. DIGE-SDS-MALDI-TOF-TOF analysis of these tissues resulted in the identification of 49 proteins that were differentially accumulated. Dehydroascorbate reductase, glutathione reductase, and catalase enzymes associated with antioxidant activities were induced in Al-treated roots. Induced enzyme proteins associated with detoxification were mitochondrial aldehyde dehydrogenase, catechol oxidase, quinone reductase, and lactoylglutathione lyase. The germin-like (oxalate oxidase) proteins, the malate dehydrogenase, wali7 and heavy-metal associated domain-containing proteins were suppressed. VHA-ATP that encodes for the catalytic subunit A of the vacuolar ATP synthase was induced and two ATPase subunit 1 isoforms were suppressed. Several proteins in the active methyl cycle, including SAMS, quercetin 3-O-methyltransferase and AdoHcyase, were induced by Al stress. Other induced proteins were isovaleryl-CoA dehydrogenase and the GDSL-motif lipase hydrolase family protein. NADPH-dependent flavin reductase and beta-hydroxyacyl-ACP dehydratase were suppressed.

Slow release versus water soluble Fertilization affects nutrient leaching and growth of potted chrysanthemum

Abstract In two experiments, ‘Charm’ and ‘Delano’ chrysanthemum [Dendranthema x grandiflorum (Ramat.) Kitamura] were grown in a peat‐based root medium using standard greenhouse cultural practices. Fertilization treatments included (1) alternate liquid fertilization (ALF): water‐soluble formulation of 15N‐4.3P‐24.9K (15–10–30) at 536 mgL‐1 N alternated with tap water irrigation; (2) Constant Liquid Fertilization (CLF): 15N‐4.3P‐24.9K(15–10–30)at268 mgL‐1 Napplied at each irrigation; (3) slow release resin‐coated fertilizer (SRR): slow release formulation of 12N‐4.3P‐14.1K(12–10–17); and (4) slow release tablets (SRT): slow release formulation of 14N‐1.7P‐4.9K (14–4–6). Irrigation volume and timing of application were arbitrary for all plants in the first experiment, but they were determined gravimetrically for each treatment in the second experiment. Irrigation volumes exceeded container capacity by 20 to 30% (leaching fractions of 0.2 to 0.3). Leachate had lower electrical conductivity and higher pH with ...

Aluminum induced proteome changes in tomato cotyledons

Cotyledons of tomato seedlings that germinated in a 20 μM AlK(SO4)2 solution remained chlorotic while those germinated in an aluminum free medium were normal (green) in color. Previously, we have reported the effect of aluminum toxicity on root proteome in tomato seedlings (Zhou et al.1). Two dimensional DIGE protein analysis demonstrated that Al stress affected three major processes in the chlorotic cotyledons: antioxidant and detoxification metabolism (induced), glyoxylate and glycolytic processes (enhanced), and the photosynthetic and carbon fixation machinery (suppressed).

IN VITRO REGENERATION OF THE TENNESSEE CONEFLOWER (ECHINACEA TENNESSEENSIS)

SummaryTennessee coneflower [Echinacea tennesseensis (Beadle) Small] was regenerated from flower stalks, leaf sections from flowering plants, and hypocotyls and cotyledons from seedlings. Murashige and Skoog medium (MS) supplemented with naphthaleneacetic acid (NAA) at 0.54 μM and thidiazuron (TDZ) at 22.7 μM yielded the most shoots per leaf explant. NAA and 6-benzylaminopurine concentrations for optimal shoot regeneration from leaf, flower stalk, cotyledon and hypocotyl explants in MS media were 0.54 and 24.6μM, respectively. All explant types generated shoots; however, those derived from leaves and flower stalks produced the highest number of shoots per explant and highest percentage of explants with shoots. Explants cultured on media containing high levels of NAA (5.4–27 μM) formed calluses but no adventitious shoot. Leaf explants responded to a wider range of NAA concentrations than the other explant types but shoots generated from flower stalks grew the fastest. While all cytokinins tested increased the number of shoots per explant, the number of shoots in media containing TDZ was increased by nearly threefold. Regenerated shoots from all explant types cultured on MS medium supplemented with 0.25 μM indole-3-butyric acid initiated roots within 4 wk; NAA was not effective for root induction. All vernalized plantlets developed into plants that were morphologically identical to the source material.

Genetic and phytochemical diversity assessment among eleven Hypericum accessions via AFLP and HPLC analyses

ABSTRACT Phytochemical profiles and DNA fingerprints were obtained from 11 species and cultivars of Hypericum (H. androsaemum, H. calycinum, H. frondosum var. “Sunbrust”, H. grandiflorum, H. inodorum, H. moseranum, H. olympicum, H. patulum var. “Sungold”, H. perforatum, H. perforatum var. “Anthos”, and H. perforatum var. “Topas”). Accessions were identified using amplified fragment length polymorphism (AFLP) and DNA fingerprints. Although each accession had a distinctive DNA fingerprint, correlations between structurally similar plants and their DNA profiles were apparent. DNA banding patterns between each accession genetic distances were analyzed and quantified using a dendogram software program. High performance liquid chromatography (HPLC) was used to quantify the content of chlorogenic acid, hyperforin, hypericin, pseudohypericin, and rutin in methanolic extracts of each Hypericum accession. Hypericum perforatum accessions and H. inodorum contained the highest concentration of marker phytochemicals, while H. calycinum, H. grandiflorum, and H. olympicum contained the lowest concentration. AFLP profiles of the plants were correlated with their levels of marker phytochemicals enabling true to type identification and marker-assisted breeding programs.

Isolation and culture of daylily mesophyll protoplasts

Mesophyll protoplasts were isolated from leaf tissues of a diploid daylily (Hemerocallisx‘Red Magic’) by enzymatic digestion with a solution containing 0.5% Pectolyase Y-23, 0.1% Cellulase R-10, 0.1% Driselase, 0.6 M sorbitol and half-strength MS inorganic salts. When cultured on MS medium supplemented with 0.5 mg/l NAA and 0.5 mg/l BA, the protoplasts underwent sustained division to produce multicellular colonies. The optimal plating density for cell division was 0.5 × 105 protoplasts/ml. The highest plating efficiency was obtained in cultures grown in media solidified with 0.2% Gelrite. Under these conditions, formation of colonies occurred from 14% of cultured protoplasts. Calli were recovered from 9 colonies only after the cultures were treated with a conditioned medium. Intact plants were regenerated from protoplast-derived calli through organogenesis.