Main Metabolism Research Articles

Effect of metalliferous dusts from dressing works on the growth, development, main metabolic processes and yields of winter wheat In situ and under controlled conditions

The effect of air pollutants (containing mainly iron oxide) emitted by dressing works (treating iron ore) on growth, the metabolic processes and yields of winter wheat were studied in situ and under controlled conditions. Air pollutants were deposited mostly on leaves and were not removed by rain to any great extent. The ‘stubborn’ pollution on plants reduced the total pigment content of the leaves almost immediately after pollution; futhermore, the biosynthesis of various pigments continued to be reduced with the advance of the vegetative period. Respiratory rate was also found to increase in polluted plants. The dark-coloured dust layers had a damaging effect so that radiation, heat, water utilisation and transpiration values were considerably reduced. The contaminated plants developed smaller ears with a reduced number of spikelets and flowers. The seed yield was considerably reduced as a consequence of biochemical disorders and reduced fertilisation.

The effect of cement dust pollution on growth and metabolism of Helianthus annuus

The experimental described in this paper was intended to establish the effect of dust on growth and development—and on the main metabolic processes and yield—of sunflower. Helianthus annuus cv. GK 70 was sown as a test plant on the experimental plots of the Agricultural University of Keszthely. Cement dust was applied to the plant leaves in quantities based on the emission values of the Duna Cement Kiln. The effect of cement dust applied at 30 g m −2 per month was relatively slight. After 130 days height was reduced by 4·%5 compared with control plants. At 100 days the following percentage changes were found: total leaf area, 3·1%; stomatal resistance, 10%; photosynthetic pigment content, −5·7%; respiration rate, ∮10·9%; catalase activity, −22%.

Metabolism of gibberellin A29 in seeds of Pisum sativum cv. Progress No. 9; Use of [2H] and [3H]GAs, and the identification of a new GA catabolite

The metabolism of GA29 in maturing seeds of Pisum sativum cv. Progress No. 9 was further investigated, and the utility of (2)H-labelled GAs in conjuction with GC-MS is illustrated. Using [2α-(2)H1]GA29 as an internal standard, endogenous GA29 was shown to reach a maximal level (ca. 10 μg/seed) 27 days from anthesis, and to decline to ca. 1.6 μg/seed in mature seeds. In a time-course feed the metabolism of [2α-(2)H1] [2α-(3)H1]GA29 applied to 27 day old seeds, and of endogenous GA29, was compared from the (1)H:(2)H ratios in the recovered GA29. Although both [2α-(2)H1] [2α-(3)H1]GA29 and endogenous GA29 were metabolised to the same limited extent to a putative conjugate, in the main metabolic process endogenous GA29 was preferentially converted to an untraceable (i.e. unlabelled) metabolite. In contrast, endogenous GA29 and [1β,3α-(2)H2] [1β,3α-(3)H2]GA29, derived from [1β,3α-(2)H2] [1β,3α-(3)H2]GA20 in a time-course feed, were metabolised in an identical manner. In the latter case isotope loss precluded identification of the metabolite. The structure (8) has been assigned to a GA catabolite present in maturing seeds and seedlings of pea. The isotope data are consistent with this compound being the hitherto untraced metabolite of GA29 in pea.