.1.4 If hormones are active at low concentrations, why do synthetic hormones such as 2,4-D accumulate in plant cells?

1 answer

Synthetic hormones such as 2,4-D (2,4-dichlorophenoxyacetic acid) can accumulate in plant cells for several reasons, despite being active at low concentrations:

1. Uptake mechanisms: Plants have mechanisms to actively take up various molecules, including synthetic hormones, from the surrounding soil or environment. Once taken up, these hormones can accumulate in plant cells.

2. Persistence: Synthetic hormones like 2,4-D can be more resistant to degradation compared to natural hormones. They may resist degradation processes such as enzymatic breakdown or microbial activity, allowing them to persist in plant cells for longer periods and accumulate over time.

3. Binding affinity: Synthetic hormones can have a higher binding affinity to hormone receptors in plant cells than natural hormones. This means that even at low concentrations, they can bind strongly to receptors and have a potent effect on plant growth and development, leading to their accumulation.

4. Feedback regulation: In natural hormone signaling pathways, there are feedback mechanisms that regulate hormone levels in plant cells. These mechanisms ensure that hormone concentrations remain within a specific range to maintain balanced growth processes. However, synthetic hormones may not be as effectively regulated by these feedback mechanisms, resulting in their accumulation if present in excess.

It is important to note that the accumulation of synthetic hormones in plant cells can have unintended consequences, such as disrupting normal plant physiology or affecting non-target organisms in the environment.