Os05g0138300
OsLti6b may act downstream of the signaling pathway involving rice orthologues of CBF1/DREB1b[1].
Contents
Annotated Information
Function
- Two closely related genes (OsLti6a, OsLti6b), which are induced by low temperature during seedling emergence were isolated from a cold tolerant temperate japonica rice cultivar[2].
- Oslti6 genes are part of a battery of cold stress defense-related genes regulated by a common switch. The products of the cold-inducible OsLti6a and OsLti6b genes may be involved in a mechanism that prevent extensive membrane destabilization during cold stress[2].
- Both OsLti6a and OsLti6b could functionally complement the phenotypes of membrane hyperpolarization and salt sensitivity resulting from deletion of PMP3 in yeast[3].
GO assignment(s): GO:0005554,GO:0016021
Mutation
OsLti6b transgenic plants[1]:
- The wilting ratio of the WT was 59/69 after 2 days of stress, and then increased to 65/66 after 3.5 days.
- When two sense plants were subjected to 3.5 days of cold temperatures, the wilting phenotype was observed in 32 out of 59 for Plant S6 and 23 out of 58 for Plant S7.
- These frequencies were much lower, and statistically different, than those recorded for the WT and NT plants.
- Leaf tissues of the line could be less damaged than those of WT and NT plants by the treatment. For the antisense line, no significant differences were detected between the transgenic and WT plants under the same conditions.
Expression
- Os05g0138300, annotated as hydrophobic protein RCI2A (Low temperature and salt responsive protein LTI6A), and Os08g0408500, a pathogenesis-related transcriptional factor and ERF domain containing protein, were both induced when rice varieties grown under salt stress, suggesting that these genes are involved in stress signalling in both species[4].
- OsLti6a and OsLti6b exhibit a genotype-specific expression signature characterized by early and late stress-inducible expression in tolerant and intolerant genotypes, respectively. The differences in temporal expression profiles are consistent with cultivar differences in cold-induced membrane leakiness and seedling vigor. The presence of CRT/DRE promoter cis-elements is consistent with the synchronized expression of OsLti6 genes with the Crepeat binding factor/drought responsive element-binding protein (CBF/DREB) transcriptional activator[2].
- The two cDNAs, OsLti6a and OsLti6b, exhibited tissue-specific differential expression with the former showing high expression only in shoots and the latter in both shoots and roots of cold stressed S3 seedlings[2].
- The transcript of OsLti6b is increased by cold, salt, drought, or ABA treatments. In situ hybridization indicated that this transcript is highly accumulated in the ovaries and stamens of cold-treated flowers, particularly in the anther walls and vascular tissues of the filaments. OsLti6b is highly expressed in CBF1/DREB1b transgenic rice[2].
- Overexpression of OsLti6b increased cold tolerance as revealed by seedling wilting rates and ion leakages of mature leaves, demonstrating that the extent of the tolerance correlates well with its expression level[1].
- In rice, OsLti6a and OsLti6b exhibit a genotype-specific expression signature characterized by early and late stress-inducible expression in tolerant and intolerant genotypes, respectively[3].
Localization
OsLti6a and OsLti6b genes have two potential transmembrane helices covering most of the polypeptide length without organellar localization signals, indicating that they are localized in the plasma membrane[2].
Evolution
- OsLti6a and OsLti6b encode small molecular weight polypeptides of 6.2 and 6.0 kDa, respectively, and which are 85% identical and 92% similar to each other. The genes are highly conserved across evolutionary kingdoms with orthologous copies in a number of plant species (monocots and dicots) as well as lower forms of eukaryotes[2].
- The OsLti6a and OsLti6b are most closely related to the Rare Cold Inducible genes, RCI2B and RCI2A, respectively. Both polypeptides are highly hydrophobic based on grand average hydropathicity values of 1.51 and 1.42, respectively[2].
Knowledge Extension
- Differential display is an effective tool for isolating cold-inducible genes in the reproductive organs of rice. Among those genes, OsLti6b has now been characterized from transgenic plants[1].
Labs working on this gene
- Department of Crop, Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR 72701, USA
- Faculty of Biological Resources Sciences, Chonbuk National University, Chonju 561-756, Korea
- Department of Biological Sciences, University of Maine, Orono, 5735 Hitchner Hall, ME 04469, USA
- Instituto de Química, Departamento de Bioquímica, Universidade de São Paulo, Brazil
- Department of Life Science, Sogang University, Seoul 121-742, Korea
- Department of Life Science, Pohang University of Science and Technology, Pohang 790-784, Korea
- College of Agronomy and Biotechnology, China Agricultural University, China
- Asian Natural Environmental Science Center (ANESC), the University of Tokyo, Japan, 3Alkali Soil Natural Environmental Science Center, Northeast Forestry University, China
References
- ↑ 1.0 1.1 1.2 1.3 Kim S H, Kim J Y, Kim S J, et al. Isolation of cold stress-responsive genes in the reproductive organs, and characterization of the OsLti6b gene from rice (Oryza sativa L.)[J]. Plant cell reports, 2007, 26(7): 1097-1110.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Morsy M R, Almutairi A M, Gibbons J, et al. The OsLti6 genes encoding low-molecular-weight membrane proteins are differentially expressed in rice cultivars with contrasting sensitivity to low temperature[J]. Gene, 2005, 344: 171-180.
- ↑ 3.0 3.1 Chang-Qing Z, Shunsaku N, Shenkui L, et al. Characterization of two plasma membrane protein 3 genes (PutPMP3) from the alkali grass, Puccinellia tenuiflora, and functional comparison of the rice homologues, OsLti6a/b from rice[J]. BMB reports, 2008, 41(6): 448-454.
- ↑ Casu R, Hotta C T, Souza G M, et al. Functional genomics: transcriptomics of sugarcane-current status and future prospects[J]. Genetics, Genomics and Breeding of Sugarcane, 2010: 167-191.
