Root phenotypes of dwarf and "overgrowth" SLN1 barley mutants, and implications for hypoxic stress tolerance

Jorge Moriconi, Lukasz Kotula, Guillermo E. Santa-Maria, Timothy D. Colmer

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Gibberellins are central to the regulation of plant development and growth. Action of gibberellins involves the degradation of DELLA proteins, which are negative regulators of growth. In barley (Hordeum vulgare), certain mutations affecting genes involved in gibberellin synthesis or coding for the barley DELLA protein (Sln1) confer dwarfism. Recent studies have identified new alleles of Sln1 with the capacity to revert the dwarf phenotype back to the taller phenotypes. While the effect of these overgrowth alleles on shoot phenotypes has been explored, no information is available for roots. Here, we examined aspects of the root phenotypes displayed by plants with various Slnl gene alleles, and tested responses to growth in an O-2-deficient root-zone as occurs during soil waterlogging. One overgrowth line, bearing the Sln1d.8 allele carrying two amino acid substitutions (one in the amino terminus and one in the GRAS domain of the encoded DELLA protein), displays profound and opposite effects on shoot height and root length. While it stimulates shoot height, it severely compromises root length by a reduction of cell size in zones distal to the root apex. In addition, Sln1d.8 plants counteract the negative effect of the original mutation on the formation of adventitious roots. Interestingly, plants bearing this allele display enhanced resistance to flooding stress in a way non-related with increased root porosity. Thus, various Slnl gene alleles contribute to root phenotypes and can also influence plant responses to root-zone O-2 deficiency stress.

Original languageEnglish
Pages (from-to)60-70
Number of pages11
JournalJournal of Plant Physiology
Volume234
DOIs
Publication statusPublished - 2019

Cite this

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title = "Root phenotypes of dwarf and {"}overgrowth{"} SLN1 barley mutants, and implications for hypoxic stress tolerance",
abstract = "Gibberellins are central to the regulation of plant development and growth. Action of gibberellins involves the degradation of DELLA proteins, which are negative regulators of growth. In barley (Hordeum vulgare), certain mutations affecting genes involved in gibberellin synthesis or coding for the barley DELLA protein (Sln1) confer dwarfism. Recent studies have identified new alleles of Sln1 with the capacity to revert the dwarf phenotype back to the taller phenotypes. While the effect of these overgrowth alleles on shoot phenotypes has been explored, no information is available for roots. Here, we examined aspects of the root phenotypes displayed by plants with various Slnl gene alleles, and tested responses to growth in an O-2-deficient root-zone as occurs during soil waterlogging. One overgrowth line, bearing the Sln1d.8 allele carrying two amino acid substitutions (one in the amino terminus and one in the GRAS domain of the encoded DELLA protein), displays profound and opposite effects on shoot height and root length. While it stimulates shoot height, it severely compromises root length by a reduction of cell size in zones distal to the root apex. In addition, Sln1d.8 plants counteract the negative effect of the original mutation on the formation of adventitious roots. Interestingly, plants bearing this allele display enhanced resistance to flooding stress in a way non-related with increased root porosity. Thus, various Slnl gene alleles contribute to root phenotypes and can also influence plant responses to root-zone O-2 deficiency stress.",
keywords = "Adventitious roots, DELLAs, Gibberellins, Flooding, Overgrowth, Waterlogging, Tolerance, NEAR-ISOGENIC LINES, ADVENTITIOUS ROOTS, SUBMERGENCE TOLERANCE, ION CONCENTRATIONS, GIBBERELLIN, GROWTH, ARABIDOPSIS, OXYGEN, RESPONSES, AUXIN",
author = "Jorge Moriconi and Lukasz Kotula and Santa-Maria, {Guillermo E.} and Colmer, {Timothy D.}",
year = "2019",
doi = "10.1016/j.jplph.2019.01.009",
language = "English",
volume = "234",
pages = "60--70",
journal = "Journal of Plant Physiology",
issn = "0176-1617",
publisher = "Elsevier",

}

Root phenotypes of dwarf and "overgrowth" SLN1 barley mutants, and implications for hypoxic stress tolerance. / Moriconi, Jorge; Kotula, Lukasz; Santa-Maria, Guillermo E.; Colmer, Timothy D.

In: Journal of Plant Physiology, Vol. 234, 2019, p. 60-70.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Root phenotypes of dwarf and "overgrowth" SLN1 barley mutants, and implications for hypoxic stress tolerance

AU - Moriconi, Jorge

AU - Kotula, Lukasz

AU - Santa-Maria, Guillermo E.

AU - Colmer, Timothy D.

PY - 2019

Y1 - 2019

N2 - Gibberellins are central to the regulation of plant development and growth. Action of gibberellins involves the degradation of DELLA proteins, which are negative regulators of growth. In barley (Hordeum vulgare), certain mutations affecting genes involved in gibberellin synthesis or coding for the barley DELLA protein (Sln1) confer dwarfism. Recent studies have identified new alleles of Sln1 with the capacity to revert the dwarf phenotype back to the taller phenotypes. While the effect of these overgrowth alleles on shoot phenotypes has been explored, no information is available for roots. Here, we examined aspects of the root phenotypes displayed by plants with various Slnl gene alleles, and tested responses to growth in an O-2-deficient root-zone as occurs during soil waterlogging. One overgrowth line, bearing the Sln1d.8 allele carrying two amino acid substitutions (one in the amino terminus and one in the GRAS domain of the encoded DELLA protein), displays profound and opposite effects on shoot height and root length. While it stimulates shoot height, it severely compromises root length by a reduction of cell size in zones distal to the root apex. In addition, Sln1d.8 plants counteract the negative effect of the original mutation on the formation of adventitious roots. Interestingly, plants bearing this allele display enhanced resistance to flooding stress in a way non-related with increased root porosity. Thus, various Slnl gene alleles contribute to root phenotypes and can also influence plant responses to root-zone O-2 deficiency stress.

AB - Gibberellins are central to the regulation of plant development and growth. Action of gibberellins involves the degradation of DELLA proteins, which are negative regulators of growth. In barley (Hordeum vulgare), certain mutations affecting genes involved in gibberellin synthesis or coding for the barley DELLA protein (Sln1) confer dwarfism. Recent studies have identified new alleles of Sln1 with the capacity to revert the dwarf phenotype back to the taller phenotypes. While the effect of these overgrowth alleles on shoot phenotypes has been explored, no information is available for roots. Here, we examined aspects of the root phenotypes displayed by plants with various Slnl gene alleles, and tested responses to growth in an O-2-deficient root-zone as occurs during soil waterlogging. One overgrowth line, bearing the Sln1d.8 allele carrying two amino acid substitutions (one in the amino terminus and one in the GRAS domain of the encoded DELLA protein), displays profound and opposite effects on shoot height and root length. While it stimulates shoot height, it severely compromises root length by a reduction of cell size in zones distal to the root apex. In addition, Sln1d.8 plants counteract the negative effect of the original mutation on the formation of adventitious roots. Interestingly, plants bearing this allele display enhanced resistance to flooding stress in a way non-related with increased root porosity. Thus, various Slnl gene alleles contribute to root phenotypes and can also influence plant responses to root-zone O-2 deficiency stress.

KW - Adventitious roots

KW - DELLAs

KW - Gibberellins

KW - Flooding

KW - Overgrowth

KW - Waterlogging

KW - Tolerance

KW - NEAR-ISOGENIC LINES

KW - ADVENTITIOUS ROOTS

KW - SUBMERGENCE TOLERANCE

KW - ION CONCENTRATIONS

KW - GIBBERELLIN

KW - GROWTH

KW - ARABIDOPSIS

KW - OXYGEN

KW - RESPONSES

KW - AUXIN

U2 - 10.1016/j.jplph.2019.01.009

DO - 10.1016/j.jplph.2019.01.009

M3 - Article

VL - 234

SP - 60

EP - 70

JO - Journal of Plant Physiology

JF - Journal of Plant Physiology

SN - 0176-1617

ER -