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Transgenic potato plants (Solanum tuberosum L. cv. Superior) with the ability to synthesize glycinebetaine (GB) in chloroplasts (referred to as SC plants) were developed via the introduction of the bacterial choline oxidase (codA) gene under the control of an oxidative stress-inducible SWPA2 promoter. SC1 and SC2 plants were selected via the evaluation of methyl viologen (MV)-mediated oxidative stress tolerance, using leaf discs for further characterization. The GB contents in the leaves of SC1 and SC2 plants following MV treatment were found to be 0.9 and 1.43 micromol/g fresh weight by HPLC analysis, respectively. In addition to reduced membrane damage after oxidative stress, the SC plants evidenced enhanced tolerance to NaCl and drought stress on the whole plant level. When the SC plants were subjected to two weeks of 150 mM NaCl stress, the photosynthetic activity of the SC1 and SC2 plants was attenuated by 38 and 27%, respectively, whereas that of non-transgenic (NT) plants was decreased by 58%. Under drought stress conditions, the SC plants maintained higher water contents and accumulated higher levels of vegetative biomass than was observed in the NT plants. These results indicate that stress-induced GB production in the chloroplasts of GB non-accumulating plants may prove useful in the development of industrial transgenic plants with increased tolerance to a variety of environmental stresses for sustainable agriculture applications.

Plants express resistance (R) genes to recognize invaders and prevent the spread of pathogens. To analyze nucleotide binding site, leucine-rich repeat (NB-LRR) genes, we constructed a fast pipeline to predict and classify the R gene analogs (RGAs) by applying in-house matrices. With predicted ~37,000 RGAs, we can directly compare RGA contents across entire plant lineages, from green algae to flowering plants. We focused on the highly divergent NBLRRs in land plants following the emergence of mosses. We identified entire loss of Toll/Interleukin-1 receptor, NB-LRR (TNL) in Poaceae family of monocots and interestingly from Mimulus guttatus (a dicot), which leads to the possibility of species-specific TNL loss in other sequenced flowering plants. Using RGA maps, we have elucidated a positive correlation between the cluster sizes of NB-LRRs and their numbers. The cluster members were observed to consist of the same class of NB-LRRs or their variants, which were probably generated from a single locus for an R gene. Our website (http://sol.kribb.re.kr/PRGA/), called plant resistance gene analog (PRGA), provides useful information, such as RGA annotations, tools for predicting RGAs, and analyzing domain profiles. Therefore, PRGA provides new insights into R-gene evolution and is useful in applying RGA as markers in breeding and or systematic studies.

Plants synthesize compatible solutes such as glycinebetaine (GB) in response to abiotic stresses. To evaluate the synergistic and protective effect of GB, transgenic potato plants expressing superoxide dismutase (SOD) and ascorbate peroxidase (APX) targeting to chloroplasts (referred to as SSA plants) were retransformed with a bacterial choline oxidase (codA) gene to synthesize GB in chloroplast in naturally occurring non-accumulator potato plants (including SSA) under the control of the stress-inducible SWPA2 promoter (referred to as SSAC plants). GB accumulation resulted in enhanced protection of these SSAC plants and lower levels of H(2)O(2) compared with SSA and non-transgenic (NT) plants after methyl viologen (MV)-mediated oxidative stress. Additionally, SSAC plants demonstrated synergistically enhanced tolerance to salt and drought stresses at the whole-plant level. GB accumulation in SSAC plants helped to maintain higher activities of SOD, APX and catalase following oxidative, salt and drought stress treatments than is observed in SSA and NT plants. Conclusively, GB accumulation in SSAC plants along with overexpression of antioxidant genes rendered the plants tolerant to multiple environmental stresses in a synergistic fashion.

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This article reports an unsteady two-dimensional Magneto-hydrodynamic (MHD) boundary layer flow of an incompressible electrically conducting fluid over a slippery stretching sheet surrounded in a porous medium. The Roseland boundary layer approximation with the radiative heat flux is employed within the current analysis. The influence of the velocity slip, thermal radiation, heat source, and buoyancy force is also considered within the current analysis, which makes significant effects on the flow field passages. The unsteady system of non-dimensional partial differential equations (PDEs) with corresponding boundary conditions are solved by implementing the explicit finite difference scheme. In the presence of pertinent parameters such as viscous dissipation, heat source or sink, Prandtl number, Grashof number, thermal radiation, magnetic field, and Darcy number, the accurate movement of the electrically conducting fluid over a slippery sheet is shown graphically in the form of velocity, temperature, skin friction coefficient, and Nusselt number. Unlike the other studies, wherein the system of PDEs is commonly transformed into a system of ordinary differential equations via the similarity transformations, the current study provides an efficient numerical procedure to solve a given system of PDEs without using the similarity transformations which exemplify the precise movement of an electrically conducting fluid over a slippery surface. It has been anticipated that the current boundary layer analysis would provide a platform for solving the system of the nonlinear PDEs of the other unsolved boundary layer models that are associated with the two-dimensional unsteady MHD flow over a slippery stretching surface embedded in a porous medium.

As back as the Industrial Revolution, anthropogenic activities namely, power generation from fossil fuels and deforestation activities have been continuously increasing the atmospheric concentration of GHGs beyond their natural limits resulting in an enhanced greenhouse effect, vis-à-vis, an increase in global temperature. The rise in temperature could be coupled with changes in rainfall pattern, rise in sea level, and frequency and severity of extreme events namely, cyclones and droughts etc. The sum of all these changes is referred to as climate change. Climate change affects economic development in many ways, especially the agrarian economies have always depended on vagaries of nature and climate. Change in temperature, precipitation averages and extreme climate events can alter yield, income, health, sociology and physical safety. Climate change is a global phenomenon and no country is immune to it. The disappearing of the Himalayan glaciers at a fast pace would increase the probability of extreme water flows, rendering it uncontrolled will bring heavy floods, loss of life, livestock, crops and infrastructural facilities in Pakistan, India, Nepal and Bangladesh. Climate change will affect all sectors of the economy not alone agricultural sector the most as well as health, forests, energy, coastal area, biodiversity and ecology all over the globe. In this connection, it will be pertinent to give the most recent events which have taken place across Asia.