About Lesson
Physiology of germination
- Water uptake:
- Seed germination starts with the imbibition of water by dry seed coat
- Various hydrophilic groups such as –NH2, – OH, –COOH, etc. of protein, polysaccharides (polymeric carbohydrates) etc. found in the seed coat attract water and thus swelling occurs
- Due to imbibition of water, the seed coat becomes:
a) More permeable to water and oxygen
b) Less resistance to outward growth of embryo
- Respiration:
- The water uptake is accompanied by increase in respiration rate of embryo
- Initially there may be anaerobic respiration but it is soon replaced by aerobic one due to availability of oxygen
- Mobilization of reserve materials followed by de novo synthesis of different metabolism:
- As germination proceeds, there is mobilization of reserve materials to provide:
a) Building blocks for the development of embryo
b) Energy for the biosynthesis process
c) Nucleic acids for control of protein synthesis and overall embryonic development