Kamel Shaker

Prof. Dr. Kamel Shaker


Research Focus & Metrics

Academic Career Length

33Years (1994-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 May 2012 in Plant Physiology
Verified
Journal Article
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HKHarleen Kaur
Harleen Kaur
KSKamel Shaker
Kamel Shaker
NHNicolas Heinzel
Nicolas Heinzel
JRJohn Ralph
John Ralph
IGIvan Galis
Ivan Galis
IBIan T. Baldwin
Ian T. Baldwin
The organized lignocellulosic assemblies of cell walls provide the structural integrity required for the large statures of terrestrial plants. Silencing two CINNAMYL ALCOHOL DEHYDROGENASE (CAD) genes in Nicotiana attenuata produced plants (ir-CAD) with thin, red-pigmented stems, low CAD and sinapyl alcohol dehydrogenase activity, low lignin contents, and rubbery, structurally unstable stems when grown in the glasshouse (GH). However, when planted into their native desert habitat, ir-CAD plants produced robust stems that survived wind storms as well as the wild-type plants. Despite efficient silencing of NaCAD transcripts and enzymatic activity, field-grown ir-CAD plants had delayed and restricted spread of red stem pigmentation, a color change reflecting blocked lignification by CAD silencing, and attained wild-type-comparable total lignin contents. The rubbery GH phenotype was largely restored when field-grown ir-CAD plants were protected from wind, herbivore attack, and ultraviolet B exposure and grown in restricted rooting volumes; conversely, it was lost when ir-CAD plants were experimentally exposed to wind, ultraviolet B, and grown in large pots in growth chambers. Transcript and liquid chromatography-electrospray ionization-time-of-flight analysis revealed that these environmental stresses enhanced the accumulation of various phenylpropanoids in stems of field-grown plants; gas chromatography-mass spectrometry and nuclear magnetic resonance analysis revealed that the lignin of field-grown ir-CAD plants had GH-grown comparable levels of sinapaldehyde and syringaldehyde cross-linked into their lignins. Additionally, field-grown ir-CAD plants had short, thick stems with normal xylem element traits, which collectively enabled field-grown ir-CAD plants to compensate for the structural deficiencies associated with CAD silencing. Environmental stresses play an essential role in regulating lignin biosynthesis in lignin-deficient plants.

1 December 2010 in Phytochemistry Letters
Verified
Journal Article
Closed access
KSKamel Shaker
Kamel Shaker
NMNagy Morsy
Nagy Morsy
HZHeidi Zinecker
Heidi Zinecker
JIJohannes F. Imhoff
Johannes F. Imhoff
BSBernd Schneider
Bernd Schneider

1 January 2014 in BioMed Research International
Verified
Journal Article
Open access
PDF file
NSNagwa M. M. Shalaby
Nagwa M. M. Shalaby
Howaida Ibrahim Abd-AllaHowaida Ibrahim Abd-Alla
Howaida Ibrahim Abd-Alla
HAHanan Aly
Hanan Aly
MAMarzougah A. Albalawy
Marzougah A. Albalawy
KSKamel Shaker
Kamel Shaker
Jalloul BouajilaJalloul Bouajila
Jalloul Bouajila
Aim.Ducrosia anethifoliais used as flavoring additive. There have been little detailed phytochemical reports on this genus and the antidiabetic activity of this plant is not yet evaluated.Method. Structure of compounds was deduced by spectroscopic analyses. Preliminaryin vitroevaluation of the antidiabetic activity of crude extract and its furanocoumarins was carried out (α-amylase,α-glucosidase, andβ-galactosidase). Thein vivoactivity was investigated by measuring some oxidative stress markers. Biomarkers of liver injury and kidney were also determined.Results. Eight linear furanocoumarins, psoralen, 5-methoxypsoralen, 8-methoxypsoralen, imperatorin, isooxypeucedanin, pabulenol, oxypeucedanin methanolate, oxypeucedanin hydrate, and 3-O-glucopyranosyl-β-sitosterol, were isolated. All compounds were reported for the first time from the genusDucrosiaexcept pabulenol. The blood glucose level, liver function enzymes, total protein, lipid, and cholesterol levels were significantly normalized by extract treatment. The antioxidant markers, glucolytic, and gluconeogenic enzymes were significantly ameliorated and the elevated level of kidney biomarkers in the diabetic groups was restored. The compounds showed inhibitory activity in a concentration dependant manner. Imperatorin and 5-methoxypsoralen showed the most potent inhibiting power.Conclusion.D. anethifoliaextract showed hypoglycemic, hypolipidemic, and antioxidant effect as well as ameliorating kidney function. This extract and some linear furanocoumarins exhibited carbohydrate metabolizing enzymes inhibitory effect.

1 November 1995 in Phytochemistry
Verified
Journal Article
Closed access
MEM.HAni A. Elgamal
M.HAni A. Elgamal
KSKamel Shaker
Kamel Shaker
KPKarl Pöllmann
Karl Pöllmann
KSKarlheinz Seifert
Karlheinz Seifert

1 February 1997 in Phytochemistry
Verified
Journal Article
Closed access
KPKarl Pöllmann
Karl Pöllmann
SGStefan Gagel
Stefan Gagel
MEM.HAni A. Elgamal
M.HAni A. Elgamal
KSKamel Shaker
Kamel Shaker
KSKarlheinz Seifert
Karlheinz Seifert

17 August 2010 in Chemistry & Biodiversity
Verified
Journal Article
Closed access
PDF file
KSKamel Shaker
Kamel Shaker
MMMichael Müller
Michael Müller
MGM. Abdel Ghani
M. Abdel Ghani
HDHans‐Martin Dahse
Hans‐Martin Dahse
KSKarlheinz Seifert
Karlheinz Seifert