Potential biochemical, genetic and molecular markers of deterioration advancement in seeds of oilseed rape (Brassica napus L.)

Abstract

Seed aging occurs relatively fast in crops and it is a process that delays germination as well as reducing its rate and even causing total loss of seed viability. Hence, it is a problem for seed banks, farmers and seed companies that deal with seed storage. The purpose of the research was to unravel genetic, biochemical and molecular events accompanying natural oilseed rape (Brassica napus L.) seed aging and thus to find potential markers of seed deterioration advancement, in order to facilitate the checking of seed quality and the ability to quickly take measures to protect them from dying. In this study, it is shown that low seed vigour is characterised by low intensity of DNA synthesis, which can quickly be measured by means of flow cytometry, changes in RNA quality, low sugar levels, increased proline content and superoxide dismutase activity, decreased ascorbate peroxidase activity, as well as abscisic acid content. Furthermore, it is demonstrated that the expression of BnRSH1 and BnRSH3, encoding for enzymes responsible for metabolism of the effectors of the stringent response (guanosine tetra- and pentaphosphate) that function in chloroplasts to regulate transcription, translation and metabolites levels, is downregulated in seeds of low vigour. Besides indicating potential markers of oilseed rape seed quality, we also propose a mechanism of seed dormancy regulation via the abscisic acid-stringent response module.