Tuffleroot

Tuffleroot is a rare flowering plant that originated on Planet Vegeta. These roots were used by the Tuffles as a weapon to extinguish the Saiyan race. However, many of these roots were very rare to come across, meaning the Saiyans still emerged victorious during the great war. The roots only fully affect pure Saiyans and don't cause harm to hybrids. Tuffleroots play a vital role in Dragon Ball Super, as they are used by Lord Binder to weaken and kill Goku and Vegeta. 
Saiyan's cannot handle the effects of the Tuffleroot. The root reacts with the Saiyan's great-ape bio-structure hidden within and infects it with a very powerful poison. This poison drains the Saiyan's energy and eventually kills them (if exposed for long enough). Although, Lord Binder kills Goku and Vegeta, whilst they were drained. 
The Super Saiyan God/Super Saiyan Blue transformations only multiply the root's abilities. 
== Origin ==
Tuffleroot were grown especially to eradicate the Saiyans on Planet Plant. However, these roots require specific conditions to grow. An old legend for-tolled that there was only six Tuffleroots during the war. These roots were considered the highest-risk the Saiyans feared during the war. Lord Binder, a war-lord who came into power after the destruction of Lord Frieza and King Cold, successfully created a Tuffleroot using old remains. 
Binder traveled to Earth disguised as an alien in need. He then exposes the Tuffleroot to Goku and Vegeta, causing them to instantly fall unwell. Furthermore, Binder kills Goku and Vegeta.