Os10g0528300

Os10g0528300 is Oryza sativa Indica Group mRNA for glutathione S-transferase (gstu4 gene).

Annotated Information

Function

Three glutathione S-transferases (GSTs: OsGSTU3, OsGSTU4 and OsGSTU12) that belong to the plant-specific tau class were markedly overexpressed in roots following Cd（Cadmium） exposure.GSTs have been reported to be involved in the direct quenching of Cd ions, forming GSH–Cd complexes (Adamis et al., 2004).The RT-PCR product levels of the osgstu3 and osgstu4 genes in rice roots increase in response to salicylic acid,jasmonic acid and the auxina-naphthalene acetic acid, as well as heavy metals. Heavy metals were found to rapidly and markedly induce osgstu4 and osgstu3 in Oryza sativa. Stress responses of osgstu4 and osgstu3 suggest involvement in the detoxification of heavy metals or stress metabolites in rice roots. Osgstu4 and osgstu3 were induced by heavy metals and hypoxic stress and were differentially responsive to salt stress in rice roots, and suggested that reactive oxygen species and redox changes are involved in the complex stress response regulation of osgstu4 and osgstu3 expression.These results suggest that OsGSTU4 can be used as a good candidate for the generation of stress-tolerant crop plants.This gene is associated gene that was consistently induced in response to drought, salt, ABA, and osmotic stress.The precise nature of the in vivo reactions catalyzed by many GSTs remains uncertain. In many cases, it is not clear whether their primary function is as a conjugase, a peroxidase, or both.

Expression

Many evidences show crosstalk between various developmental processes and environmental stimuli. The relationship between tissue-developmental stage-specific expression pattern and stress responses of few GST genes.OsGSTU4is preferentially expressed in the root and stages of seed development and was also found to be highly up-regulated by plant hormones, abiotic stress, arsenate stress and biotic stress conditions. The osgstu4 and osgstu3 genes and deduced proteins exhibited all hallmarks of GSTU proteins and genes: a single intron, an auxin response and the three conserved amino acids that form the plant GST signature motif [30]. Osgstu4 and osgstu3 were not constitutively expressed in the root or in the shoot of rice seedlings,but were induced by a speci¢c set of environmental stresses, which strongly suggests stress-related functions. Salt stress, which imposes osmotic and ion-toxic e¡ects, and dehydration by partial removal of the growth solution (data not shown) rapidly induced osgstu3 in rice roots, which indicated a water de¢cit response. Salt stress caused a late induction ofosgtu4(Fig. 4), rather due to secondary stress e¡ects, and partial dehydration did not induce osgstu4 (data not shown). Consistently, the plant hormone ABA, which regulates many primary water de¢cit responses,induced osgstu3but notosgstu4(Fig. 5). Hypoxic stress, imposed by seedling submergence, inducedosgstu4andosgstu3 in the seedling roots (Fig. 4), concomitant with a marked induction of rice alcohol dehydrogenase 1 [34]. A hypoxic stress response has so far not been reported for plant GSTs,which often are associated with oxidative stress. However,the observation that the early dehydration-induced Atgstf4 (erd13) gene was expressed when whole plants were transferred to liquid medium [18] may indicate a hypoxic stress response as well. Heavy metals were found to rapidly and markedly induce osgstu4 and osgstu3at concentrations as low as 20WM Cd and 30WMZn(Fig. 5A),which is generally considered a typical heavy metal response. Plants respond to heavy metals with a variety of detoxi¢cation pathways as well as responses to secondary stress e¡ects. The observed stress responses ofosg stu4 andosgstu3suggest involvement in the detoxi¢cation of heavymetals or stress metabolites in rice roots.

Evolution

Previous research identified a total of 79 GST genes in the rice genome and classified them in various families. On the basis of protein sequence alignment and

evolutionary relationship, fifty two (52) GST genes were included in tau, 17 in phi, 4 in zeta, two in DHAR, two in EF1G and one each in theta and tetrachlorohydroquinone dehalogenase (TCHQD) classes.

Phylogenetic relationship among rice and Arabidopsis GST proteins and their classification. The unrooted tree was constructed based on multiple sequence alignment of full-length protein sequences using ClustalX program by neighbor-joining method with 1000 bootstrap replicates. The numbers at the nodes represent bootstrap values (≥ 500) from 1000 replicates. All the rice and Arabidopsis GST proteins grouped into seven classes. The bar indicates 0.1 substitutions per site. The cluster of Tau class GST genes present only in rice is indicated in box.

Labs working on this gene

Department of Biology, Faculty of Science, University of Ottawa

References

Jain, M., C. Ghanashyam, and A. Bhattacharjee. "Comprehensive Expression Analysis Suggests Overlapping and Specific Roles of Rice Glutathione S-Transferase Genes During Development and Stress Responses." BMC Genomics 11 (2010): 73.

Jo, H. J., J. J. Lee, and K. H. Kong. "A Plant-Specific Tau Class Glutathione S-Transferase from Oryza Sativa with Very High Activity against 1-Chloro-2,4-Dinitrobenzene and Chloroacetanilide Herbicides." [In English]. Pesticide Biochemistry and Physiology 101, no. 3 (Nov 2011): 265-69.

Lee, K., D. W. Bae, S. H. Kim, H. J. Han, X. Liu, H. C. Park, C. O. Lim, S. Y. Lee, and W. S. Chung. "Comparative Proteomic Analysis of the Short-Term Responses of Rice Roots and Leaves to Cadmium." [In English]. Journal of Plant Physiology 167, no. 3 (2010): 161-68.

Moons, A. "Osgstu3 and Osgtu4, Encoding Tau Class Glutathione S-Transferases, Are Heavy Metal- and Hypoxic Stress-Induced and Differentially Salt Stress-Responsive in Rice Roots." FEBS Lett 553, no. 3 (Oct 23 2003): 427-32.

Sharma, R., A. Sahoo, R. Devendran, and M. Jain. "Over-Expression of a Rice Tau Class Glutathione S-Transferase Gene Improves Tolerance to Salinity and Oxidative Stresses in Arabidopsis." PLoS One 9, no. 3 (2014): e92900.