THE LIPOXYGENASE ISOZYMES IN SOYBEAN [GLYCINE MAX(L) MERR] LEAVES - CHANGES DURING LEAF DEVELOPMENT, AFTER WOUNDING, AND FOLLOWING REPRODUCTIVE SINK REMOVAL
Dm. Saravitz et Jn. Siedow, THE LIPOXYGENASE ISOZYMES IN SOYBEAN [GLYCINE MAX(L) MERR] LEAVES - CHANGES DURING LEAF DEVELOPMENT, AFTER WOUNDING, AND FOLLOWING REPRODUCTIVE SINK REMOVAL, Plant physiology, 107(2), 1995, pp. 535-543
The levels of individual lipoxygenase isozymes in soybean [Glycine max
(L.) Merr.] leaves were assessed during leaf development, after mecha
nical wounding, and in response to reproductive sink removal. Native i
soelectric focusing followed by immunoblotting was employed to examine
individual lipoxygenase isozymes. In leaves of all ages, two distinct
classes of lipoxygenase isozymes were detected. One class of lipoxyge
nase isozymes had nearly neutral isoelectric points (pls) ranging from
pH 6.8 to 7.2. The other class of lipoxygenase isozymes had acidic pl
s ranging from pH 4.7 to 5.6. During leaf development, all of the neut
ral lipoxygenase isozymes and most of the acidic isozymes were present
in greatest abundance in the youngest leaves examined and declined in
amount as leaf age increased. However, four acidic lipoxygenase isozy
mes (pl = 4.70, 4.80, 4.90, 4.95) were more abundant in intermediate-a
ge leaves than in either the youngest or oldest leaves examined. Follo
wing mechanical wounding of leaves, these same four acidic isozymes al
so increased in abundance both locally and systemically in leaves from
wounded plants. Unlike the specific effects of wounding on the lipoxy
genase isozymes in leaves, reproductive sink removal stimulated a gene
ral increase in most of the acidic lipoxygenase isozymes in leaves.