Background and purpose: Inhibition of cholesteryl ester transfer protein (CETP) with torcetrapib in humans increases plasma high density lipoprotein (HDL) cholesterol levels but is associated with increased blood pressure. In a phase 3 clinical study, evaluating the effects of torcetrapib in atherosclerosis, there was an excess of deaths and adverse cardiovascular events in patients taking torcetrapib. The studies reported herein sought to evaluate off-target effects of torcetrapib. Experimental approach: Cardiovascular effects of the CETP inhibitors torcetrapib and anacetrapib were evaluated in animal models. Key results: Torcetrapib evoked an acute increase in blood pressure in all species evaluated whereas no increase was observed with anacetrapib. The pressor effect of torcetrapib was not diminished in the presence of adrenoceptor, angiotensin II or endothelin receptor antagonists. Torcetrapib did not have a contractile effect on vascular smooth muscle suggesting its effects in vivo are via the release of a secondary mediator. Treatment with torcetrapib was associated with an increase in plasma levels of aldosterone and corticosterone and, in vitro, was shown to release aldosterone from adrenocortical cells. Increased adrenal steroid levels were not observed with anacetrapib. Inhibition of adrenal steroid synthesis did not inhibit the pressor response to torcetrapib whereas adrenalectomy prevented the ability of torcetrapib to increase blood pressure in rats. Conclusions and implications: Torcetrapib evoked an acute increase in blood pressure and an acute increase in plasma adrenal steroids. The acute pressor response to torcetrapib was not mediated by adrenal steroids but was dependent on intact adrenal glands.

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The establishment rate of warm-season turf and forage grasses propagated by sprigs or cuttings is of economic importance by determining not only how quickly an area may be utilized but also by influencing the extent of weed invasion. We monitored 'Tifton 85' bermudagrass [Cynodon dactylon (L.) Pers.] vegetative growth response to the application of ethephon (2-chloroethylphosphonic acid), an ethylene-producing compound, and how this treatment affected subsequent vegetative establishment. Responses of established Tifton 85 plants to ethephon treatment when compared with untreated plants included a 22% reduction in plant height, node swelling, bud swelling at the crown, terminal leaf necrosis, chlorotic striping of young developing leaves, and a 118% and 101% increase in leaf/stem fresh and dry weight ratios, respectively. Swelling of ethephon-induced buds appeared to be due to a transient arrest in sprouting. Swelled buds finally sprouted 9 d following ethephon treatment. In glasshouse experiments, vegetative cuttings taken from ethephon treated plants produced 112% more roots under a range of water stress conditions 8 d after cutting removal, and produced 10-fold higher number of tillers at 6 d after planting in soil than untreated cuttings. Tiller production in the soil establishment study was not statistically different between ethephon treated and untreated plants after 21 d. These glasshouse results indicated that it may be feasible to develop ethephon treatments that improve establishment rate and subsequent stand quality of Tifton 85 bermudagrass in field/commercial applications. M ANY ECONOMICALLY DESIRABLE warm-season grasses must be established via vegetative propagation. This includes many bermudagrass forage and turf cultivars and stargrasses (Cynodon sp.), St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze], and pangolagrass (Digitaria eriantha Stent.

The effect of accelerated aging (AA) and seed priming on specific seed enzymes was studied in soybeans. Aging seeds for 48 and 96 h at 41°C and 100% humidity reduced germination from 92% to 68% and 0%, respectively. Malate dehydrogenase (MDH) glutamate dehydrogenase (GDH), and esterase were assayed in extracts from dry and imbibing seeds. Malate dehydrogenase activity was the least affected by AA treatments. Certain GDH isozyme activity was reduced by 17% after 48 h of AA and almost completely lost after 96 h. Imbibing for 24 h increased GDH activity in 48 h-accelerated-aged seeds but not the 96 h-aged seeds. Two esterase isozymes in dry seeds showed a 77% loss of activity after 48 h of AA. This treatment increased the total esterase activity, with the greatest activity observed after 96 h of AA. This was due to the appearance of a diffuse high molecular weight (HMW) region of activity observed on native polyacrylamide gels and specifically induced in the embryonic axes. Imbibing 48-h-accelerated-aged seeds for 48 h caused a reappearance of the two esterase enzymes lost during aging. The HMW esterase staining region also appeared after imbibing unaged seeds for 24 h. Seed priming, caused a response similar to imbibition for each enzyme except the HMW esterase activity. Priming 48-h-accelerated-aged seeds reduced the HMW esterase activity. This was not observed during imbibition of aged seeds and indicates the first identification of a specific enzymatic response unique to a seed priming treatment.

Experiments were performed to determine if RAPD profiles developed using total DNA isolated from soybean seed could be affected by the physiological state or the quality of the seed. RAPD profiles were developed using template DNA isolated from a single seed lot of soybean (Glycine max L. cv. Kirby). High quality seeds were used to produce four populations varying in either quality or physiological state: untreated control seed ambient temperature and humidity storage for 12 months, accelerated aging at 41°C and 100% relative humidity for 48 h, and controlled hydration (seed priming). One hundred and eighty-eight primers were used to create separate RAPD profiles from total DNA isolated from each set of seed and from soybean leaf tissue. Sixteen polymorphisms from 14 primers were identified as a result of seed treatments. Six primers showed nine polymorphisms in RAPD profiles of ambient-stored seed DNA, while four and two primers produced polymorphisms in reactions using accelerated aged or primed-seed template DNA, respectively. Two primers showed a polymorphic fragment in vegetative DNA not observed in any of the seed DNA samples. Ten of the observed polymorphisms were due to the appearance of a DNA fragment in response to a specific seed treatment while six were the result of the treatment-induced loss of a DNA fragment. The six polymorphisms resulting from the loss of a major fragment were all due to ambient-temperature seed storage. Results were reproducibly obtained from multiple DNA isolations using three separate DNA isolation procedures involving either multiple seed or a single seed as the template source. Therefore, genetically identical seed can consistently display RAPD polymorphisms as a response to the environmental exposure.

No abstract

-The moisture content of peanut kernel (Arachis hypogaea L.) at digging ranges from 30 to 50% on a wet basis (w.b.). The seed moisture content must be reduced to 10.5% or below before seeds can be graded and marketed. After digging, peanuts are cured on a window sill for two to five days then mechanically separated from the vine. Heated air is used to further dry the peanuts from approximately 18 to 10% moisture content w.b. Drying is required to maintain peanut seed and grain quality. Traditional dryers pass a high temperature and high humidity air stream through the seed mass. The drying time is long because the system is inefficient and the high temperature increases the risk of thermal damage to the kernels. New technology identified as heat pipe technology (HPT) is available and has the unique feature of removing the moisture from the air stream before it is heated and passed through the seed. A study was conducted to evaluate the performance of the HPT system in drying peanut seed. The seeds inside the shells were dried from 17.4 to 7.3% in 14 hours and 11 minutes, with a rate of moisture removal of 0.71% mc per hour. This drying process caused no reduction in seed quality as measured by the standard germination, accelerated ageing and field emergence tests. It was concluded that the HPT system is a promising technology for drying peanut seed when efficiency and maintenance of physiological quality are desired.Index terms: Arachis hypogaea, quality, vigor, germination, conditioning. SECAGEM DE SEMENTES DE AMENDOIM COM AR À TEMPERATURA AMBIENTE EBAIXA UMIDADE RELATIVA RESUMO -O grau de umidade da semente de amendoim no momento do arranquio da planta varia de 30 a 50% em base úmida (b.u.). Após o arranquio, as plantas são secadas em média por dois a cinco dias, quando, então, as vagens são separadas mecanicamente das plantas. Na seqüência, ar aquecido é utilizado para secar a semente de amendoim na vagem a 10,5% de umidade b.u. ou menos, antes de ser classificada, armazenada e comercializada. A secagem é requerida para manter a qualidade da semente e do grão de amendoim. Secadores tradicionais operam com fluxo de ar com altas temperatura e umidade relativa, através da massa de sementes. O período de secagem é longo porque o sistema tradicional de secagem é ineficiente e a alta temperatura aumenta o risco de dano térmico à semente. Nova tecnologia, identificada como "heat pipe technology" (HPT), está disponível e tem como característica remover a umidade do ar antes dele ser aquecido e passado através da massa de sementes. No presente estudo sementes dentro das vagens foram secadas de 17,4 para 7,3% de umidade b.u. em 14 horas e 11 minutos, com taxa de remoção da umidade de 0,71% por hora de secagem. O processo de secagem "HPT" não causou redução na qualidade fisiológica da semente, avaliada pelos testes de germinação, envelhecimento acelerado e emergência no campo. Concluiu-se que o sistema "HPT" é uma tecnologia promissora para a secagem da semente de amendoim, principalmente quando eficiência e ma...

-Under subtropical and tropical environments soybean seed (Glycine max (L.) Merrill) are harvested early to avoid deterioration from weathering. Careful after-harvest drying is required and is an important step in maintaining the physiological quality of the seed. Soybean seed should be harvested when the moisture content is in a range of 16-20%. Traditional drying utilizes a high temperature air stream passed through the seed mass without dehumidification. The drying time is long because the system is inefficient and the high temperature increases the risk of thermal damage to the seed. New technology identified as heat pipe technology (HPT) is available and has the unique feature of removing the moisture from the air stream before it is passed through the seed mass at the same environmental temperature. Two studies were conducted to evaluate the performance of HPT for dry soybean seed. In the first study the seeds were dried from 17.5 to 11.1% in 2 hours and 29 minutes and in the second sudy the seeds were dried from 22.6 to 11.9% in 16 hours and 32 minutes. This drying process caused no reduction in seed quality as measured by the standard germination, tetrazolium-viability, accelerated aging and seedling vigor classification tests. The only parameter that indicated a slight seed quality reduction was tetrazolium vigor in the second study. It was concluded that the HPT system is a promising technology for drying soybean seed when efficiency and maintenance of physiological quality are desired.