Pea seeds germination

PETRUZZELLI, L., KUNZ, C., WALDVOGEL, R., MEINS, F., JR., LEUBNER-METZGER, G., Distinct ethylene- and tissue-specific regulation of beta-1,3-glucanases and chitinases during pea seed germination., Planta, 1999, 209, 195-201. 

Using [ " C]malonyl-CoA as precursor, microsomal fractions from pea seeds, germinated for 24 h, are able to label arachidic and, sometimes, behenic acids. At a concentration of 10 M, both diallate and triallate inhibited labeling of these fatty acids it was only at 10 " M that a different pattern of labeled fatty acids was seen (Table 3.10). Thus, the rather selective... 

Various assay methods have been used to detect the presence of inhibitory substances. These include some of the classical tests used by investigators of growth-promoting substances—i.e., the various Avena coleoptile assays which utilize intact, decapitated, or isolated cylinders and the split pea stem test. Effects on seed germination and seedling shoot or root growth and development have also been measured in addition to other visible expressions of inhibition. Details of many of these tests have been compiled by Mitchell et al. (99). Tests have been carried out in Petri dishes, with various solution culture techniques, and by sand and soil culture. Effects so measured may or may not be similar to those obtained under field situations— i.e., the establishment of inhibition under controlled conditions pro-... 

FANG, T-Y., BAISTED, D.J., 2,3-Oxidosqualene cyclase and cycloartenol-S-adenosylmethionine methyltransferase activitites in vivo in the cotyledon and axis tissues of germinating pea seeds, Biochem. J., 1975,150, 323-328. 

Williams, R.J. and Leopold, A.C. Changes in glass transition temperatures in germinating pea seeds. Seed Sci. Res., 5,117,1995. 

Seed germination decreases phytate and Increases phytase activity (Table X). A 22% decrease in phytic acid occurs during 5 days of soybean germination (62). Phytase activity in soybeans Increased 227% compared to an Increase of 907-3756% in peas. 

Riboflavin-catalyzed photooxidation products of indole-3-acetic acid have an inhibitory effect on the growth of Schizosaccharomyces pombe. These products also affect E. coli and other bacteria, and inhibit the growth of tomato-root tips and the germination of pea seeds. Infrared spectroscopy has aided in the identification of these photooxidation products (Fukuyama and Moyed, 1964) as 3-hydroxymethyloxindole and 3-methyleneoxindole. Both are converted to 3-methyloxindole, which was also identified by infrared spectroscopy, and is a nontoxic substance. 

In vivo synthesis of AdoMet by plants was demonstrated by Davies (1966) who showed that washed discs of turnip storage tissue incubated with methionine accumulated AdoMet to a concentration of about 0.2 /amoles/g fresh weight. The methyl group of AdoMet was not metabolized at a detectable rate, and it was thought that most of the AdoMet was localized in the vacuole. In vivo turnover of AdoMet has been demonstrated in germinating pea seeds (Dodd and Cossins, 1969). These experiments were consistent also with the possibility that the sulfur moiety of the products of AdoMet metabolism was being returned (at least partially) to the AdoMet pool. 

The concentration of AdoMet is approximately 40 fiM in germinating pea seeds (Dodd and Cossins, 1968) and approximately 14-30 fiM in L. paucicostata (Table I and Fig. 5). These concentrations are within the range in which activity of threonine synthase is very sensitive to changes in AdoMet concentration (Madison and Thompson, 1976 Aarnes, 1978 Thoen et al., 1978). The concentration of AdoMet in L. paucicostata that had been grown in the presence of exogenous methionine (Fig. 5) was approximately 300 p,M. At this concentration, threonine synthase is almost maximally stimulated by AdoMet (Madison and Thompson, 1976 Thoen etal, 1978). 

Cotyledons of developing or germinating pea seeds contain two forms of glucan phosphorylase which are electrophoretically and immunologi-cally identical with the cytosolic (isozyme I) and the plastidic (enzyme III cf. 6) phosphorylase form from pea leaflets. For pea cotyledons the dual intracellular location of phosphorylase was ensured by indirect immunofluorescence. Using this technique, isozyme I was localized in the cytosol of parenchyma cells of cotyledons whereas the other isozyme was visualized in the stromal space of amyloplasts or proplastid-like organelles (data not shown). 

FIGURE 1. Effect of varying concentrations of polyadenylated RNA isolated from cotyledons of germinating pea seeds on the rate of in-vitro translation (total protein synthesis)... 

When pea seeds were germinated in the dark and exposed daily to a 1 hr heat-shock the morphology of the plantlets was altered in a remarkable way. Leaves were expanded, hooks opened, stems shortened and second leaves already visible by... 

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