Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2011-4-18
pubmed:abstractText
• Downregulation of hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) in alfalfa (Medicago sativa) reduces lignin levels and improves forage quality and saccharification efficiency for bioethanol production. However, the plants have reduced stature. It was previously reported that HCT-down-regulated Arabidopsis have impaired auxin transport, but this has recently been disproved. • To address the basis for the phenotypes of lignin-modified alfalfa, we measured auxin transport, profiled a range of metabolites including flavonoids and hormones, and performed in depth transcriptome analyses. • Auxin transport is unaffected in HCT antisense alfalfa despite increased flavonoid biosynthesis. The plants show increased cytokinin and reduced auxin levels, and gibberellin levels and sensitivity are both reduced. Levels of salicylic, jasmonic and abscisic acids are elevated, associated with massive upregulation of pathogenesis and abiotic stress-related genes and enhanced tolerance to fungal infection and drought. • We suggest that HCT downregulated alfalfa plants exhibit constitutive activation of defense responses, triggered by release of bioactive cell wall fragments and production of hydrogen peroxide as a result of impaired secondary cell wall integrity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1469-8137
pubmed:author
pubmed:copyrightInfo
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.
pubmed:issnType
Electronic
pubmed:volume
190
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
627-39
pubmed:meshHeading
pubmed-meshheading:21251001-3,3'-Diaminobenzidine, pubmed-meshheading:21251001-Acyltransferases, pubmed-meshheading:21251001-Adaptation, Physiological, pubmed-meshheading:21251001-Biological Transport, pubmed-meshheading:21251001-Colletotrichum, pubmed-meshheading:21251001-Down-Regulation, pubmed-meshheading:21251001-Gene Expression Profiling, pubmed-meshheading:21251001-Gene Expression Regulation, Plant, pubmed-meshheading:21251001-Gibberellins, pubmed-meshheading:21251001-Indoleacetic Acids, pubmed-meshheading:21251001-Lignin, pubmed-meshheading:21251001-Medicago sativa, pubmed-meshheading:21251001-Models, Biological, pubmed-meshheading:21251001-Phenols, pubmed-meshheading:21251001-Phenotype, pubmed-meshheading:21251001-Plant Leaves, pubmed-meshheading:21251001-Plant Proteins, pubmed-meshheading:21251001-Plant Stems, pubmed-meshheading:21251001-RNA, Antisense, pubmed-meshheading:21251001-RNA, Messenger, pubmed-meshheading:21251001-Signal Transduction, pubmed-meshheading:21251001-Stress, Physiological, pubmed-meshheading:21251001-Triazoles
pubmed:year
2011
pubmed:articleTitle
Selective lignin downregulation leads to constitutive defense response expression in alfalfa (Medicago sativa L.).
pubmed:affiliation
Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't