Dormancy in cereals (not too much, not so little): about the mechanisms behind this trait.

RODRÍGUEZ M.V.; BARRERO J.M.; CORBINEAU F.; GUBLER F.; BENECH-ARNOLD R.L.

SEED SCIENCE RESEARCH

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2015 vol. 25 p. 99 - 119

0960-2585

As in other cultivated species, dormancy can be seenas a problem in cereal production, either due to itsshort duration or to its long persistence. Indeed, cerealcrops lacking enough dormancy at harvest can beexposed to pre-harvest sprouting damage, while along-lasting dormancy can interfere with processesthat rely on rapid germination, such as malting or theemergence of a uniform crop. Because the ancestorsof cereal species evolved under very diverseenvironments worldwide, different mechanisms havearisen as a way of sensing an appropriate germinationenvironment (a crucial factor for winter or summerannuals such as cereals). In addition, different species(and even different varieties within the same species)display diverse grain morphology, allowing somestructures to impose dormancy in some cereals butnot in others. As in seeds from many other species, theantagonism between the plant hormones abscisic acidand gibberellins is instrumental in cereal grains forthe inception, expression, release and re-induction ofdormancy. However, the way in which this antagonismoperates is different for the various species andinvolves different molecular steps as regulatory sites.Environmental signals (i.e. temperature, light qualityand quantity, oxygen levels) can modulate thishormonal control of dormancy differently, dependingon the species. The practical implications of