Plant & Cell Physiology Research Highlights

Abstract

We began the new year with a Special Focus Issue on Seed Biology (Volume 53:1), featuring a selection of reviews and original research articles on seed maturation, dormancy and germination in a range of plant species. Following on from the creation of SEEDNET – a comprehensive genome-wide network model designed to identify genes involved in the cellular phase transition from dormancy to germination (Bassel et al. 2011) – Endo et al. (2012) described the transcriptional changes occurring in endosperm that are triggered by seed imbibition. Amongst the genes preferentially expressed in imbibed endosperm tissue were those related to cell wall modifications, cellular transport, defence responses and flavonol biosynthesis; while vacuolation was found to be a germination-associated trait. Whole seed germination physiology was the subject of a metabolic study by Bai et al. (2012). The work aimed to uncover variability between four different Arabidopsis accessions under laboratory conditions that mimicked naturally recurring diurnal hydration–dehydration cycles of precipitation, dew formation and dehydration. The authors found that glycolysisand TCA cyclerelated metabolites responded consistently to cyclic changes across all ecotypes. By contrast, amino acid content was less predictable and therefore requires further elucidation. Also in this Special Focus Issue, the roles of natural chemical compounds and hormones such as Myrigalone A, giberellic acid, abscisic acid and jasmonate were implicated in co-ordinating a range of processes during late stages of seed of development, including endosperm rupture and pre-harvest sprouting behaviour (Fernandez-Arbaizar et al. 2012; Oracz et al. 2012; Rodriguez et al. 2012).