Provide the full names for the following abbreviations:
$(1)$ $PGRs$
$(2)$ $IAA$

(N/A) $(1)$ $PGRs$ stands for $\text{Plant Growth Regulators}$. These are small,simple molecules of diverse chemical composition that regulate plant growth and development.
$(2)$ $IAA$ stands for $\text{Indole-3-Acetic Acid}$. It is the most common naturally occurring auxin in plants,responsible for cell elongation and various developmental processes.