Table I.

Frequency of different Mn-SOD activity classes among independent transgenic alfalfa plants expressing pMitSOD or pChlSOD

Class	pMitSOD	pChlSOD
	no. of plants
≤Control	8  (23)	7  (29)
1%–50% Increase	14  (40)	9  (38)
51%–100% Increase	11  (31)	7  (29)
>100% Increase	2  (6)	1  (4)

Mn-SOD activity in leaf extracts from N4 was 19% of total SOD activity as determined by activity staining of native polyacrylamide gels. Values in parentheses represent the frequencies as percentages of the total number of transgenic plants.