Protoculture is an exceptionally powerful energy source, derived from a plant called the Flower of Life. A small amount is supposedly more raw energy than a controlled nuclear reaction. Robotech Wars were fought to find and control this important resource.
The Invid were the first to utilize protoculture, somehow using the pollen of the Flower directly to power their civilization. Later, the Tirolian scientist Zor discovered how to refine the pollen of the Flower, allowing other species to make use of the energy. Powered by the near limitless fuel of protoculture, the Tirolians developed robotechnology. With their new technology they conquered many alien civilizations, renaming themselves the Robotech Masters.
Zor became disgusted with his people's misuse of protoculture and robotechnology and decided to protect his people from themselves by taking away their power source, the Protoculture Matrix. The Robotech Masters' only fertile batch of the Flower of Life was kept in a massive starship. Zor stole all his research, the battle fortress itself, and folded into unknown space. The result was disastrous, with everyone aboard killed and the ship crash landing on the planet Earth.
Starting in July of 1999, when the alien ship crashed, humanity quickly reverse-engineered robotechnology. However the nature of Protoculture wasn't entirely entirely clear, though they did understand it's role as a power source. As a result many of the secrets of the space fortress were lost on them. Afraid that the original owners of the battle fortress would come looking for the ship, the United Earth Government rebuilt it as Super Dimension Fortress-1. They were correct as ten years later the Robotech Masters sent their shock troops, the Zentraedi, to reclaim it. This was the start of the First Robotech War.
The Robotech Wars
During the First Robotech War, the crew of the SDF-1 did not know of the existence of Protoculture until an encounter with the Zentraedi resulted in the capture of three crew members, Rick Hunter, Ben Dixon, and Lisa Hayes. Brought before Dolza, they were informed of it's existence by the Supreme Leader, though he did not share it's nature with them. It was also revealed that many of the Zentraedi also did not know of it's existence. When they returned to the SDF-1, Captain Gloval showed no knowledge of Protoculture. (Macross Saga: Blind Game, First Contact, The Big Escape)
After the end of the First Robotech War, the integration of the Zentraedi into human culture lead to Protoculture becoming common knowledge, though the exact intricacies of it weren't clear. In 2014, the SDF-1 was almost totally destroyed during the Malcontent Uprisings, its ruined shell embedded in the Earth. The Army of the Southern Cross, the replacement for the RDF, named the site SX Point 83 and forbade anyone from entering it. Deep within it, unbeknownst to humanity, the Flower of Life began to grow and spread.
Desperate to regain their energy source which was desperately running low, the Robotech Masters themselves led an assault on Earth. Additionally, they created a clone of Zor, called Zor Prime, to act as a subversive agent among the humans. A perfect copy of the original, Zor Prime had the same thoughts and opinions, and eventually turned against his creators. More importantly, he realized the presence of the Flower of Life would inevitably attract a threat even worse than the Robotech Masters: the Invid, a race of parasitic lifeforms who thrived off the Flower of Life, and had already devastated the galaxy in search of it. Attempting to end the danger of protoculture once and for all, Zor Prime exploded the Tirolian Mothership directly above SX Point 83. However, he underestimated the virility of the Flower of Life. Instead of disintegrating the spores, they were blown around the world. By the end of the Second Robotech War in June 2030, Earth had become a massive source of protoculture, and the Invid found them with ease.
A year later, the Third Robotech War began. Drawn to the incredible amount of the Flower of Life, the Invid easily conquered the planet and began harvesting the plant. In July of 2044, the main fleet of the REF arrived to retake the planet. While they expected to be joined by the SDF-3, which was in possession of the Protoculture Matrix, the ship never emerged from hyperspace. Faced with the threat of annihilation from the Neutron-S Missiles, the ominous implications of the REF's new "shadow technology", and a desperate plea from her daughter the Invid Regess decided to withdraw and seek out yet another new home. As the Invid left, they took the Protoculture on the planet's surface with them.
The Shadow Chronicles
Following the end of the Third Robotech War, the REF was in bad condition. Faced with a critical shortage of Protoculture, the only hope they had lay in the missing SDF-3. However, unbeknownst to all but the crew of the Icarus, the SDF-3 had been caught in a trap while testing one of the Neutron-S Missiles, and an unidentified ship had launched a bold attack trying to force them into a black hole created by the detonation of the weapon. While this effort was believed to have failed, the SDF-3 was missing in action once more, and humanity faced a new threat: the Haydonites. They had destroyed the Invid's homeworld long before, known at the time as the Children of the Shadow, and sought the destruction of all Protoculture and every species that used it.
- The Flower of Life could possibly be native to the Invid's original homeworld, though this has never been confirmed.