NATURAL AGING - POLY(A) POLYMERASE IN GERMINATING EMBRYOS OF TRITICUM-DURUM WHEAT

The viability of seeds is associated with ageing and storage conditions. A loss of viability is accompanied by slow germination, reduced growth, and a decline in protein and poly(A)(+)RNA synthesis. This paper reports on the activity of poly(A) polymerase in dry and germinating embryos of Triticum durum Desf. cv. Cappelli caryopses of different ages and viability. The enzyme was present as a single form during ageing and germination. The poly(A) polymerase was active at decreasing levels in all aged dry embryos, in parallel with loss of viability. Its activity strongly increased during the germination only in viable embryos. The observed increase was due to de novo synthesis of the enzyme. Poly(A) polymerase synthesis was low during germination of less viable embryos and absent in older ones. Reduced poly(A) polymerase activity in dry or germinated wheat embryos may cause a shortening of poly(A) chains in vitro and a decline in poly(A)(+)RNA synthesis. (C) 1995 Annals of Botany Compan