Germination, survival and growth of the coleoptile of rice under combined NaC1 and anoxia when submerged

Budiastuti Kurniasih

    Research output: ThesisDoctoral Thesis

    Abstract

    [Truncated abstract] In many tidal lowland and coastal areas, direct seeded rice is often exposed to flooding in saline water. Understanding the physiological adaptations of submerged (non-transpiring) rice seedlings in these unfavorable conditions will provide new information on salt tolerance mechanism under submergence. In aerated salinity, submerged rice seeds germinated and tolerated at least 200 mM NaCl. Na+ and Cl- were used by seedlings as osmotica, by maintaining tissue concentrations approximately similar to those in the external medium during the quasi-steady state. With less organic solutes available and decreases of Na+ and Cl- concentrations with time, osmotic pressure in roots was probably maintained by restricted growth (i.e. less volume expansion). At 200 mM NaCl, supplemental Ca2+ at 5 and 10 mM alleviated~24% of the growth inhibition in roots, but had no effects in shoots. The different responses of shoots and roots to the different addition of Ca2+ might be due to the increase of K+/Na+ ratio in roots but not in shoots. In a combination of NaCl and anoxia, intact rice seedlings tolerated at least 100 mM, whereas excised coleoptile tips tolerated only 50 mM NaCl. In this energy starvation, Na+ and Cl- concentrations in shoots of intact seedlings were~30% less than concentrations in shoots of seedlings submerged in aerated solutions. In anoxic intact seedlings, an increase of ethanol production at 50 mM NaCl compared to that in 0.3 mM NaCl indicated that more energy was required for cell maintenance. Despite a 25% shoot growth inhibition, anoxic rice seedlings were able to survive at 100 mM NaCl by maintaining K+/Na+ ratio and also turgor pressure.
    LanguageEnglish
    QualificationDoctor of Philosophy
    StateUnpublished - 2013

    Fingerprint

    coleoptiles
    hypoxia
    germination
    rice
    seedlings
    shoots
    growth retardation
    calcium
    submergence
    energy
    ethanol production
    turgor
    osmotic pressure
    salt tolerance
    saline water
    solutes
    starvation
    lowlands
    salinity
    seeds

    Cite this

    @phdthesis{a83305b51cc342de89a727ed61c9f4e4,
    title = "Germination, survival and growth of the coleoptile of rice under combined NaC1 and anoxia when submerged",
    abstract = "[Truncated abstract] In many tidal lowland and coastal areas, direct seeded rice is often exposed to flooding in saline water. Understanding the physiological adaptations of submerged (non-transpiring) rice seedlings in these unfavorable conditions will provide new information on salt tolerance mechanism under submergence. In aerated salinity, submerged rice seeds germinated and tolerated at least 200 mM NaCl. Na+ and Cl- were used by seedlings as osmotica, by maintaining tissue concentrations approximately similar to those in the external medium during the quasi-steady state. With less organic solutes available and decreases of Na+ and Cl- concentrations with time, osmotic pressure in roots was probably maintained by restricted growth (i.e. less volume expansion). At 200 mM NaCl, supplemental Ca2+ at 5 and 10 mM alleviated~24{\%} of the growth inhibition in roots, but had no effects in shoots. The different responses of shoots and roots to the different addition of Ca2+ might be due to the increase of K+/Na+ ratio in roots but not in shoots. In a combination of NaCl and anoxia, intact rice seedlings tolerated at least 100 mM, whereas excised coleoptile tips tolerated only 50 mM NaCl. In this energy starvation, Na+ and Cl- concentrations in shoots of intact seedlings were~30{\%} less than concentrations in shoots of seedlings submerged in aerated solutions. In anoxic intact seedlings, an increase of ethanol production at 50 mM NaCl compared to that in 0.3 mM NaCl indicated that more energy was required for cell maintenance. Despite a 25{\%} shoot growth inhibition, anoxic rice seedlings were able to survive at 100 mM NaCl by maintaining K+/Na+ ratio and also turgor pressure.",
    keywords = "Anoxia, Ion uptake, NaC1 salinity, Ethanol production, Rice germination, Energy consumption, Seedling growth",
    author = "Budiastuti Kurniasih",
    year = "2013",
    language = "English",

    }

    Germination, survival and growth of the coleoptile of rice under combined NaC1 and anoxia when submerged. / Kurniasih, Budiastuti.

    2013.

    Research output: ThesisDoctoral Thesis

    TY - THES

    T1 - Germination, survival and growth of the coleoptile of rice under combined NaC1 and anoxia when submerged

    AU - Kurniasih,Budiastuti

    PY - 2013

    Y1 - 2013

    N2 - [Truncated abstract] In many tidal lowland and coastal areas, direct seeded rice is often exposed to flooding in saline water. Understanding the physiological adaptations of submerged (non-transpiring) rice seedlings in these unfavorable conditions will provide new information on salt tolerance mechanism under submergence. In aerated salinity, submerged rice seeds germinated and tolerated at least 200 mM NaCl. Na+ and Cl- were used by seedlings as osmotica, by maintaining tissue concentrations approximately similar to those in the external medium during the quasi-steady state. With less organic solutes available and decreases of Na+ and Cl- concentrations with time, osmotic pressure in roots was probably maintained by restricted growth (i.e. less volume expansion). At 200 mM NaCl, supplemental Ca2+ at 5 and 10 mM alleviated~24% of the growth inhibition in roots, but had no effects in shoots. The different responses of shoots and roots to the different addition of Ca2+ might be due to the increase of K+/Na+ ratio in roots but not in shoots. In a combination of NaCl and anoxia, intact rice seedlings tolerated at least 100 mM, whereas excised coleoptile tips tolerated only 50 mM NaCl. In this energy starvation, Na+ and Cl- concentrations in shoots of intact seedlings were~30% less than concentrations in shoots of seedlings submerged in aerated solutions. In anoxic intact seedlings, an increase of ethanol production at 50 mM NaCl compared to that in 0.3 mM NaCl indicated that more energy was required for cell maintenance. Despite a 25% shoot growth inhibition, anoxic rice seedlings were able to survive at 100 mM NaCl by maintaining K+/Na+ ratio and also turgor pressure.

    AB - [Truncated abstract] In many tidal lowland and coastal areas, direct seeded rice is often exposed to flooding in saline water. Understanding the physiological adaptations of submerged (non-transpiring) rice seedlings in these unfavorable conditions will provide new information on salt tolerance mechanism under submergence. In aerated salinity, submerged rice seeds germinated and tolerated at least 200 mM NaCl. Na+ and Cl- were used by seedlings as osmotica, by maintaining tissue concentrations approximately similar to those in the external medium during the quasi-steady state. With less organic solutes available and decreases of Na+ and Cl- concentrations with time, osmotic pressure in roots was probably maintained by restricted growth (i.e. less volume expansion). At 200 mM NaCl, supplemental Ca2+ at 5 and 10 mM alleviated~24% of the growth inhibition in roots, but had no effects in shoots. The different responses of shoots and roots to the different addition of Ca2+ might be due to the increase of K+/Na+ ratio in roots but not in shoots. In a combination of NaCl and anoxia, intact rice seedlings tolerated at least 100 mM, whereas excised coleoptile tips tolerated only 50 mM NaCl. In this energy starvation, Na+ and Cl- concentrations in shoots of intact seedlings were~30% less than concentrations in shoots of seedlings submerged in aerated solutions. In anoxic intact seedlings, an increase of ethanol production at 50 mM NaCl compared to that in 0.3 mM NaCl indicated that more energy was required for cell maintenance. Despite a 25% shoot growth inhibition, anoxic rice seedlings were able to survive at 100 mM NaCl by maintaining K+/Na+ ratio and also turgor pressure.

    KW - Anoxia

    KW - Ion uptake

    KW - NaC1 salinity

    KW - Ethanol production

    KW - Rice germination

    KW - Energy consumption

    KW - Seedling growth

    M3 - Doctoral Thesis

    ER -