The answer to whether a seed is alive is a firm yes, but its life exists in a state of suspended animation known as dormancy. A seed is a protective, self-contained biological package designed to house a miniature plant—the embryo—and its food supply. This unique biological strategy allows the plant to survive harsh conditions, effectively pausing its life cycle for days, months, or even centuries until the environment signals it is safe to emerge.
The State of Dormancy
Dormancy is a sophisticated mechanism where the seed maintains life while dramatically lowering its rate of activity to conserve energy. Most seeds that can be stored for long periods, known as orthodox seeds, achieve this by undergoing extreme desiccation, reducing their internal moisture content to below 10% of their dry weight. This low level of water fundamentally changes the cytoplasm from a fluid to a glassy, solid-like state, which severely restricts molecular movement and chemical reactions.
The reduction in water content halts most rapid biochemical processes, including respiration and cell division, preventing the embryo from consuming its stored reserves. While outwardly inert, the seed maintains a measurable, ultra-low level of metabolic activity dedicated to molecular maintenance and damage repair. This continuous process of fixing accumulated damage to DNA and proteins preserves the seed’s viability over time.
The Mechanics of Awakening
The transition from a dormant state to active growth, known as germination, begins when the seed absorbs water through a physical process called imbibition. This rapid uptake of water is the first external cue, causing the seed to swell and re-liquefying the glassy cytoplasm. The rehydration reactivates stored enzymes and initiates the synthesis of new ones, marking the awakening of the embryo.
Once activated, hydrolytic enzymes such as amylase, lipase, and protease begin to break down the stored food molecules—starch, lipids, and proteins—into simple sugars and amino acids. This fuel source is then transported to the embryonic axis, powering the restart of cellular respiration and cell division. The first visible sign of germination is the protrusion of the radicle, the embryonic root, which establishes the seedling’s connection to the soil for water and nutrient absorption.
Limits of Viability
A seed’s lifespan, or viability, is not indefinite and is governed by the species’ genetic makeup and the conditions under which it is stored. Deterioration is a continuous process of accumulated molecular damage that the seed’s repair mechanisms eventually fail to keep up with. Optimal storage involves low temperature and low moisture content, which minimizes metabolic activity and slows damage accumulation.
Most common crop seeds are viable for only a few years, but certain species possess extraordinary longevity. The oldest successfully germinated seed was a 2,000-year-old Judean date palm (Phoenix dactylifera) recovered from Masada, Israel. The sacred lotus (Nelumbo nucifera) also holds a record, with viable seeds recovered from China estimated to be around 1,300 years old.