TITLE: Normal generation of Torelli
QUESTION [5 upvotes]: The only normal generators of the Torelli group of a closed surface I can find is Powell's 1977 paper (where the presentation is a bit complicated and given essentially without proof). Is there any more enlightening or smaller presentation? I would also be interested in such a result for $\mbox{Aut}(\pi_1(F_g))$ (as opposed to $\mbox{Out}(\pi_1(F_g))$.
EDIT Actually, it seems that in the 1980 paper of Dennis Johnson he seems to show that Torelli is normally generated by a single element, which improves the Powell result.

REPLY [5 votes]: For the Torelli group of a surface, I gave a much easier and more geometric proof in my paper
MR2302503 (2008c:57049) 
Putman, Andrew(1-CHI)
Cutting and pasting in the Torelli group. (English summary) 
Geom. Topol. 11 (2007), 829–865. 
This proof was simplified quite a bit by Hatcher and Margalit in their paper "Generating the Torelli group" (to appear in L'Enseignement Mathématique).
For $\text{Aut}(F_n)$, modern proofs can be found in the paper 
MR2336078 (2008k:57029) 
Bestvina, Mladen(1-UT); Bux, Kai-Uwe(1-VA); Margalit, Dan(1-UT)
Dimension of the Torelli group for Out(Fn). (English summary) 
Invent. Math. 170 (2007), no. 1, 1–32. 
and in my paper "The complex of partial bases for $F_n$ and finite generation of the Torelli subgroup of $Aut(F_n)$" with Matt Day.