Chapter 9: Strategies For Engineering Stress Tolerance by Shahril Efzueni Rozali https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu BTC653: Plant Biotechnology en-us 2020-04-20 01:08:01 UTC 2020-04-21 04:42:35 UTC hello@padlet.com Causes yiunteng https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516306641 Air pollution, heavy metals, soil salinity, drought, high light intensity and high temperature, biotic stress.]]> 2020-04-20 02:47:24 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516306641 Oxidative stress in plants yiunteng https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516307454 Oxidative stress is defined as an imbalance between production of free radicals and reactive metabolites, so-called oxidants or reactive oxygen species (ROS), and their elimination by protective mechanisms, referred to as antioxidants.]]> 2020-04-20 02:48:14 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516307454 ROS family yiunteng https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516310049 -Superoxide (-O2-)
-Hydrogen peroxide (H2O2)
-Hydroxyl radical (-OH)
-Singlet oxygen (O2)]]> 2020-04-20 02:50:45 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516310049 Main sites of ROS production in plant cells yiunteng https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516315877 Mitochondria
Chloroplasts
Membranes]]> 2020-04-20 02:56:18 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516315877 ROS damage causes yiunteng https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516317562 -Reaction with macromolecules
-Damage to cellular membrane; hydroxyl radicals triggering chain reaction of lipids peroxidation.
-Oxidative damage to proteins. Involve specific amino acid modifications, fragmentation of peptide change, aggregation of crosslinked reaction products and increase to proteolysis.
-DNA base degradation, single stranded breakage, and crosslinking to protein.
-The end result is deletions, mutations, and other damaging effects.]]> 2020-04-20 02:58:00 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516317562 seb180005 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516331292 Oxidative stress is a complex chemical and physiological phenomenon encompasses both biotic and abiotic stresses in higher plants and develops as a result of overproduction and accumulation of reactive oxygen species (ROS). ]]> 2020-04-20 03:11:58 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516331292 seb180005 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516333846 The generation of ROS is caused by soil salinity, heavy metals, biotic stress, drought, air pollutants, high temperature and high light intensity.]]> 2020-04-20 03:14:41 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516333846 seb180003 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516335448 Oxidative stress is the secondary effect of many types of stress consist of pathogen attack to water-deficit stress that arises from production of free radicals and subsequent ensuing cascade of reactions. Induced damage to cells as a result of the formation of ROS.]]> 2020-04-20 03:16:14 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516335448 Answer seb180002 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516338771 Oxidative stress is a complex chemical and physiological phenomenon that accompanies virtually all biotic and abiotic stresses in higher plants and develops as a result of overproduction and accumulation of reactive oxygen species (ROS).Arises from production of free radicals and subsequent ensuingcascade of reactions.]]> 2020-04-20 03:19:30 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516338771 seb180005 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516338941 Superoxide radical (O•−2 ), singlet oxygen (1O2), hydrogen peroxide (H2O2) and hydroxyl radical (OH•)]]> 2020-04-20 03:19:41 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516338941 seb180002 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516340429 Air pollutants,soil salinity,heavy metals,biotic stress,air pollutants, drought and high light as well as temperature intensity causes the generation of ROS.]]> 2020-04-20 03:21:14 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516340429 seb180003 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516340465 The generation of ROS is caused by soil salinity, heavy metals, biotic stress, high light intensity and high temperature, drought and air pollutants.]]> 2020-04-20 03:21:17 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516340465 seb180002 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516342824 Superoxide (-O2-)
Hydrogen peroxide (H2O2)
Hydroxyl radical (˙OH)
Singlet Oxygen (O2)

]]> 2020-04-20 03:23:27 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516342824 seb180003 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516343191 Superoxide (˙O2-), hydrogen peroxide (H2O2) and hydroxyl radical (OH•)]]> 2020-04-20 03:23:50 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516343191 seb180005 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516343928 The main sites of ROS production are chloroplasts, mitochondria, peroxisome, apoplast, plasma membrane, cell walls and endoplasmic reticulum (ER).]]> 2020-04-20 03:24:22 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516343928 seb180003 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516346949 The main sites of ROS production are chloroplast, peroxisome, mitochondria and cytosol.]]> 2020-04-20 03:27:06 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516346949 seb180002 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516347455 Chloroplast 
Mitochondria
Peroxisomes
Apoplast
Plasma membrane
Cell walls
Endoplasmic reticulum]]> 2020-04-20 03:27:36 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516347455 seb180005 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516348853 The cellular damage involved reaction with macromolecules. For the damage to cellular membrane, hydroxyl radicals trigger chain reaction of lipid peroxidation. Besides, oxidative damage to proteins involve specific amino acid modifications, fragmentation of peptide chain, aggregation of crosslinked reaction products and increased to proteolysis. The oxidative damage to DNA included base degradation, single-stranded breakage and crosslinking to protein, causing deletions, mutations and other damaging genetic effects.]]> 2020-04-20 03:28:37 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516348853 masterekaphan https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516350246 Oxidative stress is a complex chemical and physiological phenomenon that accompanies both biotic and abiotic stresses in higher plants and develops as result of overproduction and accumulation of reactive oxygen species (ROS).]]> 2020-04-20 03:29:57 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516350246 seb180002 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516351683 Cellular damage caused by ROS is:
- Reaction with macromolecules
-Damage to cellular membrane hydroxyl radicals triggering chain
reaction of lipid peroxidation
-Oxidative damage to proteins – involve specific amino acid
modifications, fragmentation of peptide chain, aggregation of
crosslinked reaction products and increased to proteolysis
-DNA – base degradation, single-stranded breakage, and crosslinking
to protein
-Results in deletions, mutations, other damaging genetic effects]]> 2020-04-20 03:31:16 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516351683 masterekaphan https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516354560 The generation of ROS is caused by air pollutants, soil salinity, heavy metals. biotic stress, drought, high light intensity and high temperature.]]> 2020-04-20 03:34:01 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516354560 seb180003 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516354960 The cellular damage caused by ROS involves the reaction with macromolecules. The damage to cellular membrane due to hydroxyl radicals triggering chain reaction of lipid peroxidation. Oxidative damage to proteins involve specific amino acid modifications, fragmentation of peptide chain, aggregation of
crosslinked reaction products and increased to proteolysis. DNA–base degradation, single-stranded breakage, and crosslinking to protein results in deletions, mutations, other damaging genetic effects.]]> 2020-04-20 03:34:24 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516354960 seb180005 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516355749 Superoxide Dismutase(SOD), Catalase(CAT), Ascorbate Peroxidase(APX),
Monodehydroascorbate reductase(MDHAR), Dehydroascorbate
reductase(DHAR), Glutathione Reductase(GR) and Guaiacol
Peroxidase(GPX)]]> 2020-04-20 03:35:08 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516355749 masterekaphan https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516357133 Superoxide radical (O.-2), singlet oxygen (1O2), hydrogen peroxide (H2O2) and hydroxyl radical (OH.)]]> 2020-04-20 03:36:28 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516357133 seb180002 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516357286 Superoxide Dismutase (SOD)
Ascorbate peroxidase (APX)
Catalase (CAT)
Monoadehydroascorbate reductase (MDHAR)
Dehydroascorbate reductase (DHAR)
Glutathione reductase (GR)
Guaiacol peroxidase (GPX)

]]> 2020-04-20 03:36:36 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516357286 seb180005 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516358279 Aacorbic Acid (AA), Reduced glutathione (GSH), α-tocopherol, carotenoids, phenolics, flavonoids and amino acid cum osmolyte
proline.]]> 2020-04-20 03:37:34 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516358279 Main sites of ROS production masterekaphan https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516359593 - Chloroplast
- Miitochondria
- peroxisome
- apoplast
- plasma membrane
- endoplasmic reticulum]]> 2020-04-20 03:38:44 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516359593 yiunteng https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516360310 -GO, glycolate oxidase
-3PGA,3-phosphoglycerate
-RuBisCo, ribulose
1,5-bisphosphate carboxylase/oxygenase
-RuBP, ribulose
1,5-bisphosphate
-SOD,superoxide dismutase
-XO, xanthine oxidase
-CAT, catalase 
-APX,ascorbate peroxidase.]]> 2020-04-20 03:39:27 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516360310 seb180003 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516360340
  • Superoxide Dismutase(SOD), Catalase(CAT)
  • Ascorbate Peroxidase(APX)
  • Monodehydroascorbate reductase (MDHAR)
  • Dehydroascorbate reductase (DHAR)
  • Glutathione Reductase (GR)
  • Guaiacol Peroxidase(GPX)
    • ]]>     2020-04-20 03:39:29 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516360340     seb180002 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516360780 Ascorbic acid (AA)
    Reduced Glutathione (GSH)
    Alpha Tocopherol
    Carotenoids
    Flavonoids
    Proline]]>     2020-04-20 03:39:50 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516360780     seb180003 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516362556
  • Ascorbic acid (AA)
  • Reduced Glutathione (GSH)
  • α-tocopherol
  • carotenoids
  • phenolics
  • flavonoids 
  • proline.

    • ]]>     2020-04-20 03:41:03 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516362556     masterekaphan https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516363195 Superoxide Dismutase (SOD),
    Catalase (CAT), 
    Ascorbate Peroxidase (APX),
    Monodehydroascorbate reductase
    (MDHAR),
    Glutathione Reductase (GR) and
    Guaiacol Peroxidase (GPX)

    ]]>     2020-04-20 03:41:39 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516363195     seb180005 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516363263
  • SOD - Under environmental stresses,SOD forms the first line of defense against ROS-induced damages. The SOD catalyzes the removal of O•−2 by dismutating it into O2 and H2O2. This removes the possibility of OH• formation by the Haber-Weiss reaction.
  • CAT - A tetrameric heme-containing enzyme responsible for catalyzing the dismutation of H2O2 into H2O and O2. CAT is unique amongst antioxidant enzymes in not requiring a reducing equivalent. Stressful conditions demand greater energy generation and expenditure of the cell.
    This is fulfilled by increased catabolism which generates H2O2. CAT removes the H2O2 in an energy efficient way.
  • APX- An integral component of the Ascorbate-Glutathione (ASC-GSH) cycle. APX performs dismutation of H2O2
    in the cytosol and the chloroplast. The APX reduces H2O2 to H2O and DHA,using Ascorbicacid(AA) as a reducing agent.
  • GSH - A low molecular weight thioltripeptide (γ-glutamyl-cysteinyl-glycine) with high reductive potential. A central cysteine residue with nucleophilic character
    is the source of its reducing power. GSH scavenges H2O2, 1O2, OH • and O•−2 and protects the different biomolecules by forming adducts (glutathiolated) or by reducing them in presence of ROS or organic free radicals and generating GSSG as a by-product. GSH also helps
    in the formation of phytochelatins via phytochelatin synthase, which helps to chelate heavy metal ions and thus scavenges another potential source of ROS formation in plants.
    • ]]>     2020-04-20 03:41:43 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516363263     yiunteng https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516364629 -Ascorbic acid (AA)
    -Reduced Glutathione (GHS)
    -Alpha - Tocopherol
    -Carotenoids
    -Flavonoids
    -Proline]]>     2020-04-20 03:43:02 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516364629     seb180002 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516365829 SOD: Under environmental stresses, SOD forms the first line of defense against ROS-induced damages. The SOD catalyzes the removal of O−2 by dismutating it into O2 and H2O2. This removes the possibility of OH formation by the Haber-Weiss reaction.
    CAT: CAT is a tetrameric heme-containing enzyme responsible for catalyzing the dismutation of H2O2 into H2O and O2. 
    APX: APX is an integral component of the Ascorbate-Glutathione (ASC-GSH) cycle. While CAT predominantly scavenges H2O2 in the peroxisomes, APX performs the same function in the cytosol and the chloroplast. The APX reduces H2O2 to H2O and DHA, using Ascorbic acid (AA) as a reducing agent.
    GSH: GSH scavenges H2O2, 1O2, OH, and O−2 and protects the different biomolecules by forming adducts (glutathiolated) or by reducing them in presence of ROS or organic free radicals and generating GSSG as a by-product. GSH also plays a vital role in regenerating AA to yield GSSG. The GSSG thus generated is converted back to GSH, either by de novo synthesis or enzymatically by GR. GSH also helps in the formation of phytochelatins via phytochelatin synthase]]>     2020-04-20 03:44:07 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516365829     masterekaphan https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516367608 Ascorbic Acid (AA), Reduced glutathione (GSH), alpha tocopherol , carotenoids, phenolics, flavonoids and aminoacidcumosmolyte proline.]]> 2020-04-20 03:45:52 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516367608 seb180003 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516371027
  • SOD: Under environmental
    stresses, SOD forms the first line of defense against ROS-induced damages. The SOD catalyzes the removal of O2•− by dismutating it into O2 and H2O2. This removes the possibility of OH• formation by the Haber-Weiss reaction.
  • CAT: A tetrameric heme-containing enzyme responsible for catalyzing the dismutation of H2O2 into H2O and O2. It is
    unique amongst antioxidant enzymes in not requiring a reducing equivalent.
  • APX: While CAT predominantly scavenges H2O2 in the peroxisomes, APX performs the same function in the cytosol and the chloroplast. The APX reduces H2O2 to H2O
    and DHA, using Ascorbic acid (AA) as a reducing agent.
  • GSH: GSH scavenges H2O2, 1O2, OH, and O−2 and protects the different biomolecules by forming adducts (glutathiolated) or by reducing them in presence of ROS or organic free radicals and generating GSSG as a by-product. GSH also plays a vital role in regenerating AA to yield GSSG. The GSSG thus generated is converted back to GSH, either by de novo synthesis or enzymatically by GR. GSH also helps in the formation of phytochelatins via phytochelatin synthase.
    • ]]>     2020-04-20 03:48:31 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516371027     yiunteng https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516372892 -SOD: Under environmental
    stresses, SOD forms the first line of defense against ROS-induced
    damages. The SOD catalyzes the removal of O•−2 by dismutat-
    ing it into O2 and H2O2. This removes the possibility of OH• formation by the Haber-Weiss reaction.
    -CAT: a tetrameric heme-containing enzyme responsible for catalyzing the dismutation of H2O2 into H2O
    and O2. This is necessary since stressful conditions demand greater energy generation and expenditure of the cell. This is fulfilled by increased catabolism which generates H2O2. CAT removes the H2O2 in an energy efficient way. 
    -APX: APX reduces H2O2 to H2O
    and DHA, using Ascorbic acid (AA) as a reducing agent in cytosol and chloroplast.
    -GSH: GSH scavenges H2O2, 1O2, OH•, and O•−2 and protects the different biomolecules by forming adducts (glutathiolated) or by reducing them in presence of ROS or organic free radicals and generating GSSG as a by-product. GSH also plays a vital role in regenerating AA to yield GSSG.]]>     2020-04-20 03:50:17 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516372892     masterekaphan https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516373852 The cellular damage caused by ROS involves the reaction with macromolecules. The damage of cellular membrane due to hydroxyl radicals triggering chain reaction of lipid peroxidation. Oxidative damage to proteins involve specific amino acid modifications, fragmentation of peptide chain, aggregation of crosslinked reaction products and increased to proteolysis. DNA-based degradation, single stranded breakage, and crosslinking to protein results in deletions, mutations, other damaging genetic materials.]]> 2020-04-20 03:51:13 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516373852 seb180002 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516377248 2 Strategies for engineering tolerance to oxidative stress in plants are:
    -Increase level of enzymes that remove ROS
    -Increase level of antioxidant compounds that react with ROS]]>     2020-04-20 03:54:18 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516377248     seb180002 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516379195 Strategy 1: Expression of enzymes involved in scavenging ROS:

    SODs catalyse the reaction – superoxide radical combines with two hydrogen ions – form oxygen and hydrogen peroxide
    Broad family of SOD enzymes requiring different metal ions for activity. Predominating different cellular components e.g. transgenic tobacco – containing each class of enzymes – withstand oxidative stress
    Not clear – protective effect is due to the removal of superoxide by the
    enzyme, or the hydrogen peroxide product enhances stress tolerance by inducing other stress-related genes
    Cu/Zn-SOD, Mn/SOD and Fe-SOD genes together in alfalfa – increase
    winter hardiness

    Strategy 2: Production of antioxidants enzymes
    Actions of enzymatic antioxidants ascorbate peroxidase – catalyzed the ascorbate to scavenge ROS glutathione peroxidase – using glutathione (GSH) to reduce H2O2,
    producing GSSG glutathione reductase – reduce GSSG to glutathione (GSH), provide resistance to oxidative stress resulting from paraquat treatment.
    Glutathione synthase – increasing cellular concentration of gluthatione.

    ]]>     2020-04-20 03:56:11 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516379195     Two strategies for engineering tolerance masterekaphan https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516383030 1) Increase level of enzymes that remove ROS
    2) Increase level of antioxidant compounds that react with ROS]]>     2020-04-20 03:59:50 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516383030     seb180003 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516383058
  • Increase level of enzymes that remove ROS
  • Increase level of antioxidant compounds that react with ROS
    • ]]>     2020-04-20 03:59:52 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516383058     seb180005 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516387064
  • Expression of enzymes involved in scavenging ROS
  • Production of antioxidants enzymes
    • ]]>     2020-04-20 04:03:33 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516387064     seb180005 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516388757
  • SODs catalyse the reaction of superoxide radical combines with two hydrogen ions to form oxygen and hydrogen peroxide. Broad family of SOD enzymes is requiring different metal ions for activity and predominating different cellular components. For instance, transgenic tobacco containing each class of enzymes is capable to withstand oxidative stress. Cu/Zn-SOD, Mn/SOD and Fe-SOD genes together in alfalfa shown an increase in winter hardiness.
  • Production of antioxidants enzymes such as ascorbate peroxidase catalyzed the ascorbate to scavenge ROS. Besides, glutathione peroxidase using glutathione (GSH) to reduce H2O2, producing GSSG. Moreover, glutathione reductase reduce GSSG to glutathione (GSH), provide resistance to oxidative stress resulting from paraquat treatment. In addition, glutathione synthase increase cellular concentration of gluthatione.

    • ]]>     2020-04-20 04:05:22 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516388757     seb180003 https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516390246 Strategy 1: Expression of enzymes involved in scavenging ROS
    • SODs catalyse the reaction in which the superoxide radical combines with two hydrogen ions to form oxygen and hydrogen peroxide. Broad family of SOD enzymes 
      require different metal ions for activity and predominate different cellular components. For an example, transgenic tobacco containing each class of enzymes is able withstand
      oxidative stress. 
    Strategy 2: Production of antioxidants enzymes
    • Ascorbate peroxidase catalyzed the ascorbate to scavenge ROS. Glutathione peroxidase using glutathione (GSH) to reduce H2O2,
      producing GSSG. Glutathione reductase reduce GSSG to glutathione (GSH), provide
      resistance to oxidative stress resulting from paraquat treatment. Glutathione synthase increasing cellular concentration of
      gluthatione.

    ]]>     2020-04-20 04:06:51 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516390246     yiunteng https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516424558 Increase expression of enzyme involved in scavenging ROS.

    Increase production of antioxidants enzymes]]>     2020-04-20 04:40:27 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516424558     yiunteng https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516427369 1. Expression of enzyme involved in scavenging ROS.
    -SODs catalyse the reaction
    -Superoxide radical combines with two hydrogen ions 
    -Form oxygen and hydrogen peroxide.

    2. Production of antioxidant enzymes
    ascorbate peroxidase – catalyzed the ascorbate to scavenge ROS

    glutathione peroxidase – using glutathione (GSH) to reduce H2O2,
    producing GSSG

    glutathione reductase – reduce GSSG to glutathione (GSH), provide
    resistance to oxidative stress resulting from paraquat treatment.

    Glutathione synthase – increasing cellular concentration of
    gluthatione.]]>     2020-04-20 04:43:18 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516427369     masterekaphan https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516554747 - SOD: Under environmental stresses, SOD forms the first line of defense against ROS- induced damages. The SOD catalyzes the removal of O2- by dismutating it onto O2 and H2O2. This remove the possibility of OH- formation by the Haber-Weiss reaction.
    - CAT- A tetrametric heme-containing enzyme responsible for catalyzing the dismutation for H2O2 into H2O and O2. It is unique among antioxidants enzymes in not requiring a reducing equivalent.
    - APX- While CAT predominatly scavenges H2O2 in the peroxisomes, APX performs the same function in the cytosol and the chloroplast. The APX reduces  H2O2 to H2O and DHA, using Ascorbic acid as a reducing agent.
    - GSH- GSH scavenges H2O2, 1O2, OH and O-2 and protects the different molecules by forming adducts or by reducing them in presence of ROS or organic free radicals and generating GSSG as a by-product.



    ]]>     2020-04-20 06:32:14 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516554747     masterekaphan https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516817073 In strategy 1, SODS catalyse the reaction of superoxide radial combines with two hydrogen ions to form oxygen and hydrogen peroxide. Broad family of SOD enzymes is requiring different metal ion for activity and presominating different cellular components. For instance, transgenic tobacco containing each class of enzyme is capable to withstand oxidative stress.
    In strategy 2, production of antioxidants enzymes such as ascorbate peroxidase catalyzed the ascorbate to scavenge ROS. Besides, glutathione peroxidase using GSH to reduce H2O2 producing GSCC. Moreover, glutathione reductase reduce GSCC to GSH, provide resistance to oxidative stress resulting from paraquat treatment. ]]>     2020-04-20 08:36:02 UTC https://padlet.com/shahrilefzueni/3l8st92laz9qi3iu/wish/516817073