Trehalose accumulation in rice plants confers high tolerance levels to different abiotic stresses. Proc Natl Acad Sci USA

Departments of Molecular Biology and Genetics, Plant Biology, and Horticulture, Cornell University, Ithaca, NY 14853, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 01/2003; 99(25):15898-903. DOI: 10.1073/pnas.252637799
Source: PubMed

ABSTRACT Trehalose is a nonreducing disaccharide of glucose that functions as a compatible solute in the stabilization of biological structures under abiotic stress in bacteria, fungi, and invertebrates. With the notable exception of the desiccation-tolerant "resurrection plants," trehalose is not thought to accumulate to detectable levels in most plants. We report here the regulated overexpression of Escherichia coli trehalose biosynthetic genes (otsA and otsB) as a fusion gene for manipulating abiotic stress tolerance in rice. The fusion gene has the advantages of necessitating only a single transformation event and a higher net catalytic efficiency for trehalose formation. The expression of the transgene was under the control of either tissue-specific or stress-dependent promoters. Compared with nontransgenic rice, several independent transgenic lines exhibited sustained plant growth, less photo-oxidative damage, and more favorable mineral balance under salt, drought, and low-temperature stress conditions. Depending on growth conditions, the transgenic rice plants accumulate trehalose at levels 3-10 times that of the nontransgenic controls. The observation that peak trehalose levels remain well below 1 mgg fresh weight indicates that the primary effect of trehalose is not as a compatible solute. Rather, increased trehalose accumulation correlates with higher soluble carbohydrate levels and an elevated capacity for photosynthesis under both stress and nonstress conditions, consistent with a suggested role in modulating sugar sensing and carbohydrate metabolism. These findings demonstrate the feasibility of engineering rice for increased tolerance of abiotic stress and enhanced productivity through tissue-specific or stress-dependent overproduction of trehalose.

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Available from: Leon Kochian, Aug 22, 2015
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    • "Moreover, numerous study have revealed that synthesis of sugar alcohols enhanced via over expression of different sets of genes. For instance, trehalose is synthesized by otsA (trehalose- 6-phosphate synthase), otsB (trehalose-6-phosphate phosphatase), and AtTPS1 and AtTPS2 (trehalose-6- phosphate synthase (Garg et al. 2002; Baea et al. 2005), mannitol, sorbitol and ononitol via action of mt1D (D-mannitol-1-phosphate dehydrogenase), S6PDH (sorbitol-6-phosphate dehydrogenase), OemaT1 (mannitol-1) and imt1 (D-myo-inositolmethyltransferase ) under stress conditions (Sheveleva et al. 1997; Abebe et al. 2003; Gao et al. 2001). "
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    ABSTRACT: Abiotic stresses collectively are responsible for crop losses worldwide. Among various abiotic stresses, drought and salinity are the most destructive. Different strategies have been adopted for the management of these stresses. Being complex traits, conventional breeding approaches have shown less success in improving salinity and drought stress tolerance. Roles of compatible solutes in salinity and drought stress tolerance have been studied extensively. At physiological level, osmotic adjustment is an adaptive mechanism involved in drought and/or salinity tolerance and permits the maintenance of turgor pressure under stress conditions. Increasing evidences from series of in vivo and in vitro studies involving physiological, biochemical, genetic, and molecular approaches strongly suggest that osmolytes such as ammonium compounds (polyamines, glycinebetaine, b-alanine betaine, dimethyl-sulfonio propionate and choline-o-sulfate), sugars and sugar alcohols (fructan, trehalose, mannitol , D-ononitol and sorbitol) and amino acids (proline and ectoine) perform important function in adjustment of plants against salinity and drought stresses. Thus, aim of this review is to expose how to osmoprotectants detoxify adverse effect of reactive oxygen species (ROS) and alleviate drought and salinity stresses. An understanding of the relationship between these two sets of parameters is needed to develop measures for mitigating the damaging impacts of salinity and drought stresses.
    Reviews in Environmental Science and Bio/Technology 07/2015; 14(3). DOI:10.1007/s11157-015-9372-8 · 2.26 Impact Factor
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    • "Recently, interest in the role of trehalose has increased because it has been shown to improve the performance of plants under abiotic stress such as drought, reduced nutrition, low temperature or salinity (Chang et al., 2013, 2014; Iordachescu and Imai, 2008). Garg et al. (2002) demonstrated that elevated trehalose accumulation in rice also conferred high tolerance to salt and drought stress. In addition, results have indicated the important role of trehalose under stressful conditions in mutation experiments (Avonce et al., 2004; Suzuki et al., 2008). "
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    ABSTRACT: Arbuscular mycorrhizal fungi (AMF) are known to improve plants stress tolerance by increasing water absorption and trehalose accumulation. However, the relationship between trehalose and AMF water transport and their role in the mycorrhizal rice water strategy at low temperature has not been established. Different temperature and exogenous trehalose treatment experiments were performed on potted non-mycorrhizal and mycorrhizal rice. The results showed that AMF enhanced rice root water uptake at both normal and low temperatures. At low temperature, the AMF aquaporin (GintAQPF) expression levels were increased and higher rice aquaporin (OsPIPs) expression levels were exhibited in mcyorrhizal rice than non-mycorrhizal rice. The increased trehalose biosynthesis gene transcripts, such as OsTPS1, OsTPS2 and OsTPP1 in mycorrhizal rice roots generated more trehalose than in non-mycorrhizal rice at either normal or low temperature. Application of exogenous trehalose demonstrated that trehalose could regulate AMF and rice water absorption by inducing the expression of GintAQPF and several OsPIPs and create better plant growth conditions. Consequently, we hypothesized that one of the mechanisms by which AMF improve plant resistance to low temperature was AMF-enhanced trehalose accumulation, which could induce AMF and host plants aquaporin expression that then maintain better water relations in mycorrhizal plants at low temperatures.
    Applied Soil Ecology 12/2014; 84:185–191. DOI:10.1016/j.apsoil.2014.07.010 · 2.21 Impact Factor
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    • "Transgenic plants carrying mtlD convert mannitol 1-phosphate to mannitol via nonspecific phosphatases [13]. Overexpression of the genes involved in the biosynthesis of osmolytes, such as mannitol [8] [14], trehalose [15], and many more in various transgenic plants showed increased abiotic-stress tolerance. The mtlD gene has been transferred to several crop species like wheat [16], eggplant [17], sorghum [18], and Maize [19] resulting in enhanced plant height, fresh and dry biomass weight, increase in salinity, and/or drought tolerance [20] [21]. "
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    ABSTRACT: In the changing global environmental scenarios, water scarcity and recurrent drought imposes huge reductions to the peanut (Arachis hypogaea L.) crop yield. In plants, osmotic adjustments associated with efficient free radical scavenging ability during abiotic stress are important components of stress tolerance mechanisms. Mannitol, a compatible solute, is known to scavenge hydroxyl radicals generated during various abiotic stresses thereby conferring tolerance to water-deficit stress in many plant species. However, peanut plant is not known to synthesize mannitol. Therefore, bacterial mtlD gene coding for mannitol 1-phosphate dehydrogenase under the control of constitutive promoter CaMV35S was introduced and overexpressed in the peanut cv. GG 20 using Agrobacterium tumefaciens-mediated transformation. A total of eight independent transgenic events were confirmed at molecular level by PCR, Southern blotting, and RT-PCR. Transgenic lines had increased amount of mannitol and exhibited enhanced tolerance in response to water-deficit stress. Improved performance of the mtlD transgenics was indicated by excised-leaf water loss assay and relative water content under water-deficit stress. Better performance of transgenics was due to the ability of the plants to synthesize mannitol. However, regulation of mtlD gene expression in transgenic plants remains to be elucidated.
    The Scientific World Journal 10/2014; 2014. DOI:10.1155/2014/125967 · 1.73 Impact Factor
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