Peanut plants

Table 4 Release of Reducing Root Exudates (e.g., Phenolics) by Peanut Plants as Affected by Fe Nutritional Status and Short-Term (10 h) Supply of a mMl-containing nutrient solution...

V. Romheld, and H. Marschner, Mechanisms of iron uptake by peanut plants 1. Reduction, chelate splitting, and release of phenolics. Plant Physiol. 77 949 (1983). 

C]PCNB metabolism was studied in vivo with 30-day-old peanut plants grown in nutrient solution that contained 17.6 ppm [I CjPCNB. Plant tissue was extracted with cold 80t methanol 48 hr after final exposure to PCNB. The extracts were made aqueous and partitioned against chloroform at pH 5.5 and against ethyl ether at pH 2. Water-soluble, chloroform-soluble, and ether-soluble metabolites were isolated by various chromatographic methods and identified by mass spectrometry and/or by synthesis. The details of these studies have been published previously (, X ... 

Precursor-product relationships were also studied in peanut plants treated with C-labeled metabolites and harvested 1 to 21 days later (, 7). 

Water-soluble residues. Peanut plants treated with [ C]PCNB for H8 hr and harvested after a 48 hr post-treatment incubation, absorbed all but 1.2 of the The roots contained... 

Figure 3. Distribution of C in plant tissues as a function of solubility. Barley, corn, cotton, peanut cell cultures, and soybeans were treated with V C] PCNB for 3 days. Lake water rich in blue green algae was treated for 9 h. Peanut plants were treated for 2 days and subjected to a 2-day post-treatment incubation.

Figure 6. Ether-soluble metabolites isolated from the roots of peanut plants treated with FCNB. This represents 13.7% of the C isolated from the roots.

Insoluble residue accounted for only 2% of the applied in peanut cell cultures harvested 14 days after treatment with, [) C]PCNB however, insoluble residue accounted for 37X of the isolated from the roots of peanut plants 33 days after treatment. When peanut cell cultures were treated with... 

Figure 12. Formation of 80% methanol-insoluble residues in peanut plants (root) and peanut cell suspension cultures treated with [ C] PCNB, S-[( C)PCF]Cys, and pentachlorothiophenol-UL- C...

The amount of chloroform-soluble C in the roots of peanut plants grown in hydroponics decreased greatly as a function of time. After 33 days, chloroform soluble C accounted for only 5 of the 14C in the roots. This was probably due to metabolism of the remaining PCNB, volatilization of some metabolites, translocation to foliar tissue, and additional metabolism of nonpolar metabolites to polar metabolites or Insoluble residue. Because of volatility, it is possible that chloroform-soluble... 

Polar methylene chloride-soluble residues. Polar methylene chloride-soluble residues were found In most of the plant tissues treated with [ C]PCNB (Figure 14). These products were only Identified In peanut IT). The polar methylene chloride-soluble metabolites from peanut, S-(PCP)Cys, S-(PCP)ThloAcetate, and S-(PCP)ThloLactate, were probably produced from S-(PCP)GSH by the pathway shown In Figure 15. Intact peanut plants treated with S-[( C)PCP]Cys and harvested 20 days later yielded S-(( C)-PCP]ThloAcetate In T.3% yield however, S-(( C)PCP]ThloLactate was not detected. An S-substltuted 2-thloacetlc acid metabolite has also been reported In the metabolism of EPTC In the rat ( 1 ). 

Figure 14. Methylene chloride- or chloroform-soluble residues were isolated from plant tissues treated with V C] PCNB. All tissues were treated for 3 days except lake water which is rich in blue green algae (9 h), peanut plants (2-day treatment/2-day post-treatment), and peanut cell cultures (1 day).

Therefore, a similar pathway appears to operate in certain mammals. When S-(PCP)ThioAcetate was introduced into peanut plants, pentachlorothioanlsole was not formed. However, other metabolites were detected, possibly glucose and amino acid conjugates similar to those reported for 2,4-D (17). 

The cysteine conjugates appeared to be key metabolil es, occupying pivotal positions in the pathway. S-(Pentachloro-phenyl)cysteine was not demonstrated in vitro, but it was a minor metabolite in peanut plants. This anomoly appeared to be due to the kinetics of the various reactions. A cysteine conjugate was clearly shown to be a key intermediary metabolite in the metabolism of the GSH conjugate of atrazine in sorghum (Figure 1). 

How does pathogen infestation affect odor emissions and does it interfere with emissions induced by insect herbivores So far, only one study has specifically looked at this cross-effect (Cardoza et al, 2002). It showed that insect feeding (beet armyworm, S. exigua) and fungus infection (white mold, Sclerotium rolfsii) resulted in distinctly different odor blends in peanut plants, whereas plants that were simultaneously infested by these two antagonists released a mix of both blends. 

Cardoza, Y. J., Alborn, H. T. and Tumlinson, J. H. (2002). In vivo volatile emissions from peanut plants induced by simultaneous fungal infection and insect damage. Journal of Chemical Ecology 28 161-174. 

Peanut Oil (Unhydrogenated) is a pale-yellow oil obtained from the kernel of the peanut plant Arachis hypogaea L. (Fam. Fabaceae) by mechanical expression or solvent extraction. It is refined, bleached, and deodorized to substantially remove free fatty acids, phospholipids, color, odor and flavor components, and miscellaneous other non-oil materials. It is a liquid at 21° to 27°, but solidifies to a gel-like consistency at 2° to 4°. It is free from visible foreign matter at 21° to 27°, but sometimes clouds at temperatures above 21°. 

The stability of oils is very important in pharmaceuticals since nonpolar drugs (for example, contraceptive steroids and neuroleptic tranquillisers) are often formulated in oily injection vehicles for intramuscular or depot injection. Injections of this type can be given, for example, once a month, and the drug exerts its pharmacological effect as it leaches out of the injection site into the bloodstream. Oils used as injection vehicles include arachis oil, from the peanut plant, olive oil, castor oil and ethyl oleate, the ethyl ester of the 18-carbon fatty acid oleic acid (Figure 8.16). 

At least two well-documented cases of plant xenobiotic metabolism to N-O-glucosides have been reported (, ). Oxamyl insecticide was converted to an N-0-glucoslde in tobacco, young peanut plants, alfalfa, and the fruit of orange and tomato ( ) (Equation 6). This... 

Carboxln fungicide was metabolized to malonanlllc acid and the glucoslde of -hydroxymalonanlllc acid In the fruit of peanut plants and In peanut cell suspension cultures ( 12 1 ) (Equation 29). Both... 

D, which Is structurally similar to MCPA, appeared to be Inco-porated into lignin (255). This was in sharp contrast to MCPA metabolism in wheat. Carboxln (aniline-l4C) metabolism in peanut cell suspension culture and the fruit of whole peanut plants is an example of tissue variation. In peanut cell suspension culture, only 2.7% of the carboxln was incorporated Into bound residue, but In the fruit of whole plants, 21% Incorporation into bound residue was observed (121). The metabolism of metrlbuzln In tomato and soybean Is an excellent example of species variation. In tomato, metrlbuzln was rapidly metabolized to N-glucosldes and only 2% was Incorporated into bound residue, but In soybean, metrlbuzln was metabolized slowly by homoglutathione conjugation and 20-30% of the metrlbuzln was incorporated into bound residue (46.95). 

Chung, I.M., M.R. Park, J.C. Chun, and S.J. Yun. 2003. Reserveratrol accumulation and reserveratrol synthase gene expression in response to abiotic stress and hormones in peanut plants. PZawf 5cZ. 164 103-109. 

Peanut plants that grow with adequate moisture overlap the row middles during the latter third of the growing season in such a fashion that the soil surface under, and between, the rows is shaded from direct sunlight. It has been shown that the mean geocarposphere temperature under these conditions (approximately 24°C) is not affected greatly by ambient temperatures (1, ). ... 

Peanut plants grown under severe drought stress, during the latter 4-6 weeks of the growing season, recede so as to partially expose the soil surface to direct sunlight, which causes an increase in geocarposphere temperature. Thus, the two major requirements (dry soil and elevated geocarposphere temperature) for preharvest afla-toxin contamination are achieved. 

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