Two Faces of One Seed: Hormonal Regulation of Dormancy and Germination

Abstract

Seed plants have evolved to maintain the dormancy of freshly matured seeds until the appropriate time for germination. Seed dormancy and germination are distinct physiological processes, and the transition from dormancy to germination is not only a critical developmental step in the life cycle of plants but is also important for agricultural production. These processes are precisely regulated by diverse endogenous hormones and environmental cues. Although ABA (abscisic acid) and GAs (gibberellins) are known to be the primary phytohormones that antagonistically regulate seed dormancy, recent findings demonstrate that another phytohormone, auxin, is also critical for inducing and maintaining seed dormancy, and therefore might act as a key protector of seed dormancy. In this review, we summarize our current understanding of the sophisticated molecular networks involving the critical roles of phytohormones in regulating seed dormancy and germination, in which AP2-domain-containing transcription factors play key roles. We also discuss the interactions (crosstalk) of diverse hormonal signals in seed dormancy and germination, focusing on the ABA/GA balance that constitutes the central node.

Bacterial inoculants for enhanced seed germination of Spartina densiflora: Implications for restoration of metal polluted areas

“…These properties could help seed germination. For instance, auxins are clearly involved in maintaining seed dormancy (Miransari and Smith, 2014;Shu et al, 2016). But, although auxins seem not to be directly related to seed germination, they become crucial once the radicle has emerged (Kucera et al, 2005;Miransari and Smith, 2014).…”

The Arabidopsis DNA Methylome Is Stable under Transgenerational Drought Stress

“…Any effect of enhanced seed dormancy on other developmental phenotypes, in this study, would have been masked by the seed stratification treatment performed prior to experimentation. Although the potential adaptive advantage of increased seed dormancy was not tested directly in this study, it would not be inconsequential, as seed dormancy dictates the environment that progeny plants would germinate in, thus having a potentially critical impact on early growth (FinchSavage and Leubner-Metzger, 2006;Shu et al, 2016). Such a trait also has been suggested to be an advantage for progeny whose parents were affected by herbivory (Agrawal, 2002;Rasmann et al, 2012).…”

The Arabidopsis Polycomb Repressive Complex 1 (PRC1) Components AtBMI1A, B, and C Impact Gene Networks throughout All Stages of Plant Development

“…7A). After embryogenesis, plants undergo the transition from seed dormancy to germination that is antagonistically regulated by two hormones, ABA and gibberellins (GA; Shu et al, 2016). During seed maturation, endogenous ABA accumulates in the seed, inducing and maintaining seed dormancy.…”