Reference "A genomics approach to the comprehensive analysis of the glutathione S-transferase gene family in soybean and maize"

Reference ID

7427

Title

A genomics approach to the comprehensive analysis of the glutathione S-transferase gene family in soybean and maize

Source

Plant physiology, 2000, vol. 124, pp. 1105-1120

Authors (5)

McGonigle-B	Keeler-S-J
Lau-S-M	Koeppe-M-K
O'Keefe-D-P

Abstract

By BLAST searching a large expressed sequence tag database for glutathione S-
transferase (GST) sequences we have identified 25 soybean (Glycine max) and 42
maize (Zea mays) clones and obtained accurate full-length GST sequences. These
clones probably represent the majority of members of the GST multigene family in
these species. Plant GSTs are divided according to sequence similarity into
three categories: types I, II, and III. Among these GSTs only the active site
serine, as well as another serine and arginine in or near the "G-site" are
conserved throughout. Type III GSTs have four conserved sequence patches mapping
to distinct structural features. Expression analysis reveals the distribution of
GSTs in different tissues and treatments: Maize GSTI is overall the most highly
expressed in maize, whereas the previously unknown GmGST 8 is most abundant in
soybean. Using DNA microarray analysis we observed increased expression among
the type III GSTs after inducer treatment of maize shoots, with different genes
responding to different treatments. Protein activity for a subset of GSTs varied
widely with seven substrates, and any GST exhibiting greater than marginal
activity with chloro-2,4 dinitrobenzene activity also exhibited significant
activity with all other substrates, suggesting broad individual enzyme substrate
specificity.