Changes in RNA and Protein Metabolism Associated with Alterations in the Germination Efficiency of Sunflower Seeds

Abstract

Precise knowledge of seed quality after harvest and during storage is of particular importance for seed producers. We analysed different sunflower seed lots (Helianthus annuusL.) characterized by extremes of germination ability. We used RNA analysis to study possible changes in gene expression in seeds unable to germinate. Total RNA content was very small in dry seeds showing a low germination ability. Capacity for total RNA synthesis at the onset of imbibition was also reduced in these seeds. In addition, correlations were found between these parameters and germination ability at 19 °C. We demonstrated a high correlation between the amount of total RNA in the dry seed, the capacity of RNA synthesis at the onset of imbibition and the seed moisture content at the time of the harvest. The ability of dry seed mRNAs to be translatedin vitrowas also reduced and seven polypeptides, from stored mRNAs, were characteristic of the cotyledons from high germinability seeds. Germination can thus be affected at several levels including membrane, enzymatic and nucleic acid deteriorations.