Seeds undergo changes in both aba content and sensitivity. Seed dormancy is an adaptive trait that does not allow the germination of an intact viable seed under favorable environmental conditions. Reversal of rdo5 1, a homolog of rice seed dormancy 4. Role of abscisic acid in seed dormancy springerlink. Auxin controls seed dormancy through stimulation of abscisic acid signaling by inducing arfmediated abi3 activation in arabidopsis xiaodong liu a, hong zhang, yang zhaob, zhengyan fenga, qun lia, hongquan yangc, sheng luand, jianming lie, and zuhua hea,1 anational key laboratory of plant molecular genetics, institute of plant physiology and ecology and bshanghai center for plant stress. Although aba abscisic acid and gas gibberellins are known to be the primary phytohormones that antagonistically regulate seed dormancy. Pdf abscisic acid and the control of seed dormany and germination. Pdf abscisic acid aba is a plant hormone that regulates seed dormancy and germination. The control of seed dormancy by abscisic acid aba has been extensively studied, but the underlying mechanism is not fully understood. Nitrate releases seed dormancy in arabidopsis thaliana col0 seeds in part by reducing abscisic acid aba levels.
Control of seed germination by abscisic acid ncbi nih. Nitrate also reduced aba levels in dry seeds when provided to the mother plant during seed development endogenous. This figure highlights abscisic and gibberellic acid metabolism. Dormant seeds from fraxinus species require cold temperature afterripening prior to germination. Abscisic acid levels and seed dormancy plant physiology. Auxin controls seed dormancy through stimulation of abscisic acid. Plant hormone interactions during seed dormancy release and. Abscisic acid aba is commonly assumed to be the primary effector of seed dormancy, but conclusive evidence for this role is lacking. Abscisic acid aba inhibits endosperm rupture but not testa rupture. Ga, ethylene and brassinosteroids brs promote endosperm rupture and. This paper reports on the relationships occurring in red rice between aba and seed dormancy. The plant hormone abscisic acid aba is the major player in mediating the adaptation of the plant to stress. The transition from dormancy to germination in seeds is a key physiological process during the lifecycle of plants.
Seed dormancy is a mechanism that prevents a viable seed from germinating when placed in an ideal environment for germination. Abscisic acid controlled sex before transpiration in. Seed dormancy is an adaptive trait that improves survival of the next generation by optimizing the distribution of germination over time. Abscisic acid aba is a plant hormone that regulates seed dormancy and germination. Pdf seed dormancy is one of the most important adaptive mechanisms in plants, which pro. Induction and release of seed dormancy is mainly under the control of abscisic acid aba and gibberellic acid ga. Nitrate led to lower levels of aba in imbibed seeds when included in the germination media exogenous nitrate. Aba levels increase during stress but decrease when stress is relieved. Seeds undergo changes in both aba content and sensitivity during seed development and germination in response to internal and external cues. Here we report the characterization of two abarelated seed dormancy regulators in arabidopsis. Jan zeevaart 19302009 was a major contributor to our understanding of aba synthesis and homeostasis.
Abscisic acid and the control of seed dormancy and germination volume 20 issue 2 eiji nambara, masanori okamoto, kiyoshi tatematsu, ryoichi yano, mitsunori seo, yuji kamiya. Seed dormancy and the control of germination finch. Get a printable copy pdf file of the complete article 924k, or click on a page image below to browse page by. Mechanisms underlining seed dormancy and seed germination control in plants. A dynamic balance of synthesis and catabolism of two antagonistic hormones, abscisic acid aba and giberellins gas, controls the equilibrium between seed. On the role of abscisic acid in seed dormancy of red rice. Abscisic acid aba is an essential repressor of seed germination. Understanding molecular mechanisms of seed dormancy for. Abscisic acid and the control of seed dormany and germination article pdf available in seed science research 2002 june 2010 with 7,697 reads how we measure reads. Abscisic acid and the control of seed dormancy and. Kermode department of biological sciences, simon fraser university, 8888 university dr, burnaby, british columbia v5a 1s6, canada abstract seed dormancy is an adaptive trait that improves survival of the next generation by optimizing the distribution of germination over time. Odr1 for reversal of rdo5, an orthologue of the rice seed dormancy 4 sdr4, and the basic helixloophelix transcription factor bhlh57.
Auxin controls seed dormancy through stimulation of. Seeds undergo changes in both aba content and sensitivity during seed development and germination in response. Wed like to understand how you use our websites in order to improve them. Aba is essential for seed maturation and also enforces a period of seed dormancy. The arabidopsis abscisic acid catabolic gene cyp707a2. The sesquiterpene abscisic acid aba regulates key events during seed formation, such as the deposition of storage reserves, prevention of precocious germination, acquisition of desintroduction control of seed germination and growth is crucial to the survival of the next generation, and there are critical checkpoints at the transitions from dormancy to germination and from germination to growth. Abscisic acid transporters cooperate to control seed germination.
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