Small RNA and transcriptional activity during development and abscission of generative organs in yellow lupine

Yellow lupin (Lupinus luteus L., Taper c.) is an important legume crop, however, formation and development of its flowers and pods is often affected by abscission of these organs. Excessive abscission of L. luteus flowers and pods represents the important economical drawback. Shedding primarily concerns flowers from the upper part of the inflorescence. Moreover, the fate of upper flowers seems to be determined during organ development before anthesis. Abscission the pods occurs mainly in the early stages of their development. Detachment of generative organs in L. luteus takes place in abscission zone (AZ) located at the basis of pedicels. During plant growth cells in AZ become competent to respond to specific signals, thus initiating organ separation. Organs development and abscission are complex controlled but the knowledge about molecular mechanism are still not completed. By controlling the activity of their target genes, small non-coding RNAs (microRNAs and siRNAs) play a significant role in regulation almost all developmental processes in plants but their contribution to the regulation of generative organ development and abscission in yellow lupine has not been studied. The aim of the study was comparison of transcriptional activity between developing flower from upper and lower parts of raceme, growing seeds and pod walls, abscised and non-abscised pods and flower pedicels in order to type the differential expressed small ncRNAs and their target genes which could be a strong evidence of their key roles in the studied processes.