To solve the problem, we need to identify the plant hormone responsible for the long-term storage of seeds.
1. Understanding the Role of Plant Hormones:
- Auxins: Promote cell elongation and are involved in phototropism and root formation.
- Ethylene: Involved in fruit ripening and leaf abscission.
- Gibberellins: Promote seed germination, stem elongation, and flowering.
- Abscisic acid (ABA): Induces seed dormancy and inhibits germination, which helps in **long-term storage of seeds**.
2. Function of Abscisic Acid:
Abscisic acid plays a crucial role in maintaining seed dormancy and preventing premature germination. This makes it vital for storing seeds over long periods.
Final Answer:
The hormone that helps in long-time storage of seeds is $ \text{Abscisic acid} $