Tryptophan boost caused by senescence occurred independently of cytoplasmic glutamine synthetase.
We examined to determine whether senescence-induced tryptophan levels are positively associated with levels of glutamine synthetase (GS1), the initial enzyme in tryptophan biosynthesis. We generated transgenic rice plants in which GS1 was suppressed by RNA interference technology. The transgenic line showed a dramatic decrease in GS1 protein and glutamine content, but the levels of tryptophan and mRNA of the key tryptophan biosynthetic genes upon senescence were comparable to those of the wild type.
Department of Biotechnology, Interdisciplinary Program of Graduate School for Bioenergy and Biomaterials, Bioenergy Research Center, Chonnam National University, Gwangju, Korea.
Sangkyu
S
Park
Kyungjin
K
Lee
Kiyoon
K
Kang
Young Soon
YS
Kim
Sungbeom
S
Lee
Soon-Jong
SJ
Kweon
Kyoungwhan
K
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D000375:Aging / Q000502:physiology*; D003600:Cytosol / Q000201:enzymology; D005974:Glutamate-Ammonia Ligase; D005973:Glutamine / Q000032:analysis; D012275:Oryza / Q000235:genetics; D030821:Plants, Genetically Modified; D034622:RNA Interference; D012333:RNA, Messenger / Q000032:analysis; D014364:Tryptophan / Q000032:analysis / Q000096:biosynthesis*
D012333:RNA, Messenger; D005973:Glutamine; D014364:Tryptophan; D005974:Glutamate-Ammonia Ligase