The weakening of endosperm cell walls is mediated by mannanases secreted from the aleurone layer of germinating barley seeds

Cereal seeds (wheat, rice, maize, barley...) constitute the first world crop. The molecular physiology of development and germination of these seeds is essential for feeding properly an increasing population (approx. 10.000 millions in 2050) in the actual context of climate change.

In this work, we have characterized the gene family encoding endo-ß-mannanases of barley (HvMAN1-6). The HvMAN1 transcripts are particularly abundant in the aleurone cells during germination, although mannans are localized to the walls of endosperm cells. This situation suggest that HvMAN1, with a peptide signal, could be secreted from the aleurone to the starchy endosperm where catalyzes the hydrolysis of mannans that besides their structural function could serve as reserve compounds during seed post-germination.