The appointment puts Annegret Kramp-Karrenbauer in pole position to take control of the party when Mrs Merkel eventually steps down or is forced from office.
Although Tauber is seen as a close associate of Merkel's, infighting within the CDU (Christian Democratic Union) led the chancellor to designate another party stalwart to draft the party's electoral platform past year. She also played a key role in Merkel's tough coalition negotiations with the centre-left Social Democrats.
After new SPD leader Martin Schulz appeared to pose a real challenge to Merkel in early 2017, AKK's effortless re-election was taken as the first sign that the CDU had nothing to fear.
After then-SPD leader Martin Schulz appeared to pose a real challenge to Dr Merkel early past year, Mrs Kramp-Karrenbauer's effortless re-election was taken as the first sign that the CDU had nothing to fear.
Pleased German Chancellor Angela Merkel's CDU CSU bloc gained 2.5 percentage points to reach 32 per cent and remains the biggest party in the country
By appointing the up-and-coming AKK to a top role in the CDU, Dr Merkel is in part responding to critics who have been calling for fresh faces to reinvigorate the party after it suffered its worst electoral result since 1949 in September.
Angela Merkel is speculated to pave the way for her "crown princess;" and to secure her legacy as chancellor, she has nominated the head of the state of Saarland, Annegret Kramp-Karrenbauer, to be the CDU's next secretary general.
Though Merkel has said she is available as chancellor for four years, the succession debate has been supercharged by the inclusion of a clause in a coalition deal with the Social Democrats (SPD) that envisages a review of the next government's progress after two years to assess whether any changes to its mission are needed.
But "to interpret her as a simple copy of Merkel would be a misunderstanding", Die Welt newspaper commented. Less than two years after that, she took over the party leadership.More news: West Brom stars could face community service after 'Taxi-gate'
AKK was also praised by the CDU's previous Saarland premier, Peter Mueller, who said "There's not a task you can't trust Annegret with".
He underwent surgery for his condition last month.
Merkel was elected general-secretary in 1998, a role that traditionally involves managing the party's campaigns and developing its political messages.
A consistent Catholic and a mother of three, the Saarland politician is seen as an appeal to the more conservative members of the CDU, who have long hoped for change, the Frankfurter Allgemeine Zeitung suggests.More news: JD Martinez to sign with Red Sox
The hard-fought coalition deal struck with Social Democrats must still be approved by the SPD's 460,000 members.
The outcome is considered wide open as the SPD's youth and left wings are fiercely opposed to another term governing in Merkel's shadow.More news: Record-breaker Kohli leads India to another easy win over SA