Seed birth to death: dual functions of reactive oxygen species in seed physiology.
BACKGROUND
Reactive oxygen species (ROS) are considered to be detrimental to seed viability. However, recent studies have demonstrated that ROS have key roles in seed germination particularly in the release of seed dormancy and embryogenesis, as well as in protection from pathogens.


METHODS
This review considers the functions of ROS in seed physiology. ROS are present in all cells and at all phases of the seed life cycle. ROS accumulation is important in breaking seed dormancy, and stimulating seed germination and protection from pathogens. However, excessive ROS accumulation can be detrimental. Therefore, knowledge of the mechanisms by which ROS influence seed physiology will provide insights that may not only allow the development of seed quality markers but also help us understand how dormancy can be broken in several recalcitrant species.


CONCLUSIONS
Reactive oxygen species have a dual role in seed physiology. Understanding the relative importance of beneficial and detrimental effects of ROS provides great scope for the improvement and maintenance of seed vigour and quality, factors that may ultimately increase crop yields.
ICAR-Directorate of Seed Research, Maunath Bhanjan, Uttar Pradesh 275103, India.
S P
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Jeevan Kumar
ICAR-Directorate of Seed Research, Maunath Bhanjan, Uttar Pradesh 275103, India, srprasad1989@yahoo.co.in.
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Rajendra Prasad
Microbial and Downstream Processing Laboratory, Department of Agricultural and Food Engineering, Indian Institute of Technology, Kharagpur 721 302, India.
Rintu
R
Banerjee
Research Program-Dry Land Cereals, International Crops Research Institute for Semi-Arid Tropics (ICRISAT), Patancheru 502324, India and.
Chakradhar
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Thammineni
D057445:Plant Dormancy / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012639:Seeds / Q000254:growth & development / Q000502:physiology*; D015398:Signal Transduction
D017382:Reactive Oxygen Species
Reactive oxygen species (ROS); embryogenesis; germination; programmed cell death (PCD); seed dormancy; seed physiology; signalling