Enhanced drought tolerance in Arabidopsis via genetic manipulation aimed at the reduction of glucosamine-induced ROS generation.
In animals, high glucose exerts some of its deleterious effects by activation of the hexosamine biosynthesis pathway (HBP), a branch of the glycolytic pathway that produces amino sugars (Daniels et al. in Mol Endocrinol 7:1041-1048, 1993; Du et al. in Proc Natl Acad Sci USA 97:12222-12226, 2000). Glucosamine (GlcN) is a naturally occurring amino sugar produced by amidation of fructose-6-phosphate. Previously, we observed that glucosamine (GlcN) inhibits hypocotyl elongation in Arabidopsis thaliana by a process involving the significant increase of reactive oxygen species. The present study investigated the relationship between GlcN-induced ROS generation and abiotic stress responses in Arabidopsis by generating two types of transgenic plant. Scavenging of endogenous GlcN by ectopic expression of E. coli glucosamine-6-phosphate deaminase (NagB) was observed to confer enhanced tolerance to oxidative, drought, and cold stress. Consistent with this result, overproduction of GlcN by the ectopic expression of E. coli glucosamine-6-phosphate synthase (GlmS) induced cell death at an early stage. Taken together, these data suggest that genetic manipulation of endogenous GlcN level can effectively lead to the generation of abiotic stress-tolerant transgenic crop plants.
Chu
Seung Hee
SH
College of Life Sciences and Biotechnology, Korea University, 1, 5-ka Anam-dong, Sungbuk-ku, Seoul, 136-713, Republic of Korea.
Noh
Ha-na
HN
Kim
Sooah
S
Kim
Kyoung Heon
KH
Hong
Suk-Whan
SW
Lee
Hojoung
H
D019747:Aldose-Ketose Isomerases / Q000235:genetics* / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D003080:Cold Temperature; D005944:Glucosamine / Q000378:metabolism* / Q000494:pharmacology; D018384:Oxidative Stress; D010788:Photosynthesis; D030821:Plants, Genetically Modified / Q000254:growth & development / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013312:Stress, Physiological / Q000235:genetics*; D014867:Water / Q000378:metabolism
D017382:Reactive Oxygen Species; D014867:Water; C020582:glucosamine-6-phosphate isomerase; D019747:Aldose-Ketose Isomerases; D005944:Glucosamine