Tomato roots

Parasorbic acid (Figure 2) was isolated from fruits of Sorbus aucuparia. Germination of mustard seed Sinapis alba) was affected adversely by parasorbic acid at 3.5 X 10-3 M and growth of excised tomato roots was inhibited at approximately 8.5 X 10 4 M (25). The acid also antagonized indoleacetic acid (IAA) in the Avena assay. Cornman 29,30) reported that parasorbic acid slowed down mitosis. Metaphase stages were observed to accumulate, but abnormalities were not detected. 

The possible involvement of polygalacturonic acid-containing molecules in the defence reactions of tomato root cells against Fusarium oxysporum was suggested about 20 years ago by their accumulation at penetration sites. Since papillae are held to serve as a resistance mechanism to fungal penetration, it was assumed that the interrelation between pectin and other polymers - such as lignin - may contribute to enhancing the hardness of these newly formed structures (Benhamou et al., 1990). 

Benhamou N. Chamberland H. Pauze F.J. (1990) Implication of pectic components in cell surface interactions between tomato root cells and Fusarium oxysporum f. sp. radicis-lycopersici / / Plant Physiol. V. 92. P. 995-1003. 

Colonization of tomato root tissues by FORL is associated with striking modifications of host cell walls, as it has been shown by ultrastructural studies which have been carried out describing the penetration of the fimgus through... 

P. Imas, B. Bar-Yosef, U. Kakafi, and R. Ganmore-Neumann, Phosphate induced carboxylate and proton release by tomato roots. Plant Soil /9/ 35 (1997). 

Most plant species are able to absorb and assimilate nitrate, ammonium, urea, and amino acids as nitrogen sources, but the response to a particular form of nitrogen varies from species to species (114). For example, optimal growth of tomato roots occurs in soil with a ratio of nitrate to ammonium of 3 1 and is inhibited if the ammonium concentration is too high (115). By contrast, white spruce has a strong preference for ammonium (116), whereas some arctic sedges prefer amino acids (117). 

To clarify the nature and activity of these toxins, rhizome exudates (washings), compounds isolated from rhizomes (dhurrin, taxiphyllin, p-hydroxybenzaldehyde), and structurally similar compounds were tested against radish and tomato root growth and growth of nine species of bacteria. Figures 4 and 5 show the results of the radish and tomato bioassay of pure compounds. Dhurrin and toxiphyllin showed little activity in these assays, whereas j>-hydroxybenzaldehyde was active in the radish bioassay. 

Figure 5. Regression analysis of tomato root growth inhibition with concentration (pPK)a-(T) g-Hydroxybenzaldehyde, y=41.39e (-) prunasin, y=38-51eD ° (A) g-Phydroxymandelonitrile, y=...

Figure 7. Tomato root growth bioassay of water leachates and...

Tomato root growth bloassay of leaf extracts. Three hundred mg samples of fully expanded leaves were taken from each plant studied. Each sample was ground with a Polytron1 in 30 ml of distilled water and the extract was filtered. Five ml aliquots of each extract were pipetted onto three layers of germination paper in a 10 by 10 by 1.5 cm plastic petri dish. Distilled water was used as a control treatment. Twelve tomato seeds were placed in a 3x4 array in each dish, and incubated at 20C for 168 hours, prior to root measurement. The experimental design was a completely randomized design with five replications (dishes) per treatment except the control which had 10 replications. The experiment was repeated each week for 9 weeks. 

Root elongation bloassay of root exudates. Only prickly sida root exudate significantly affected radish or tomato root elongation (Table II). It significantly inhibited radish root elongation and significantly stimulated tomato root elongation. 

Table II. Radish and tomato root growth bloassay of root exudates...

Dropkin, V.H. and Boone, W.R. (1966) Analysis of host-parasite relations of root-knot nematodes by single larva inoculations of excised tomato roots. 

Observations Table 1 shows the activity of the antioxidant enzymes of tomato roots after 72 h of exposure of allelochemical stress caused by S. deppei. Catalase (CAT) activity increases by 1.5 fold Ascorbate Peroxidase (APX) decreases 2.3 fold Glutathione reductase (GR) activity does not change with the treatment and Superoxide dismutase (SOD) decreases 1.3 fold. 

Observations Figure 2 shows confocal images of 48 h tomato roots exposed to S. deppei aqueous leachate and then stained with DCFDA. A higher fluorescence is observed in treated-root hairs. 

Fig. 9.4 Effect of soil solarization on root galling in tomato plants in soil infested by the root-knot nematode Meloidogyne incognita in plastic greenhouse in Sothem Italy. On the left a tomato root from solarized soil, on the right a root from nonsolarized soil, deformed by large galls...

Lycopersicon esculentum L. Fan Qie (Tomato) (root, leaf) Protein, vitamin A, thiamine, nicotinic acid, riboflavin.50 Relieve toothache, insecticide, laxative. 

Fe reduction. Sections of roots can then be viewed under the microscope and the stain located. Bell et al. (1988) have evaluated the use of ferricyanide and the use of nitro-BT, [2,2 -di-/>-nitro-phenyl-5,5 -diphenyl]-3,3 -(3,3 -dimethoxy-4,4 -biphenylene)-di-tetrazolium chloride. With ferricyanide, iron-stressed tomato plants were mainly stained on the younger roots hairs located on the laterals or primary root tip. Nitro-BT is thought to compete with Fe(III) at the same transmembrane ferric reduction site (Sijmons and Bienfate, 1983). A purple diformazan precipitate is produced on reduction. Although the roots were stained in a similar way to those incubated with ferricyanide, Bell et al. (1988) point out that further research is required to determine if nitro-BT reduction completes with ferric reduction at the same site in the tomato. The iron-stress redox activity has been shown to be localised on the plasma membrane in tomato roots (Buckout et al., 1989), and electron microscopic examination (see next section) of the roots stained with Prussian blue indicated that the PB had accumulated between the plasma membrane and the cell walls of the root hairs and epidermal cells (Wergin et al., 1988). 

Proteomic Techniques for the Study of Allelopathic Stress Produced by Some Mexican Plants on Protein Patterns of Bean and Tomato Roots... 

A. sedillense aqueous extract only inhibited the radicle growth of bean 25% but tomato radicle growth 60%. In bean root, A. sedillense aqueous extract increased the expression of 16 proteins (Table 14.1, Figs. 14.1A and 14.1B). In treated-tomato roots, 14 proteins were modified. Twelve proteins increased (1-8, 10-11, 13-14), one was detected only in this treatment (9), and another one was repressed (12) (Table 14.1 and Figs. 14.1C and 14.1D). 

D-PAGE of cytoplasmic proteins from bean and tomato roots (A) bean control (B) bean treated with A. sedillense aqueous extract (C) tomato control (D) tomato treated with A. sedillense aqueous extract (From Romero-Romero, M. T. et al. 2002, J. Chem. Ecol. 28, 601-613. With permission). 

In treated tomato roots 12 proteins were modified 10 were decreased (1-4 6-9 11 and 12) and 2 were increased (5 and 10) (Fig. 14.4, Table 14.3). Protein 5 (37.5 kDa) was N-terminal microsequenced, and 23 amino acids were obtained. Protein search showed 95% similarity to the glutathione S-transferases (EC 2.5.1.18) (GST), class-phi from Solanum commersonii, pir T07906 (Seppanen, 1997 direct submission) 90% similarity with GST from Hyoscyamus muticus, pir PQ0744 6 and 69% with GST from Nicotiania tabacum, P4644021 (Fig. 14.4). 

C. acuminata aqueous extract modified 12 proteins in tomato roots, decreasing the majority of them. The 23 amino acids of the N-terminal of protein 5 of tomato (37.5 kDa, 100% increase) showed 95% similarity to the glutathione S-transferases of other Solanaceae. In plants, GSTs play roles in normal cellular metabolism, as well as in the detoxification of a wide variety of toxic compounds. GSTs have been involved in numerous stress responses, including pathogen... 

There must be a susceptible plant. For example, a tomato plant is susceptible to damping-off disease when it is a small seedling, but is resistant to this disease when it is growing luxuriantly in midsummer. Club root fungi in the soil can attack cabbage roots, but cannot infect tomato roots. 

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