TY - JOUR
T1 - UDP-glucose pyrophosphorylase is rate limiting in vegetative and reproductive phases in arabidopsis thaliana
AU - Park, Jong In
AU - Ishimizu, Takeshi
AU - Suwabe, Keita
AU - Sudo, Keisuke
AU - Masuko, Hiromi
AU - Hakozaki, Hirokazu
AU - Nou, Ill Sup
AU - Suzuki, Go
AU - Watanabe, Masao
N1 - Funding Information:
This work was supported by the Japan Society for Promotion of Science (JSPS) [Grants-in-Aid for Special Research on Priority Areas (Nos. 18075003, 18075012, 20380002 and 20678001 to M.W., and No. 21024006 to T.I.), Grant-in-Aid for Creative Scientific Research (No. 16G3016 to M.W.)]; Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea [Technology Development Program for Agriculture and Forestry, to I.-S.N.]; JSPS [Research Fellowship of the Young Scientists to J.-I.P., K.S. and H.H.].
PY - 2010/6
Y1 - 2010/6
N2 - UDP-glucose pyrophosphorylase (UGPase) is an important enzyme in the metabolism of UDP-glucose, a precursor for the synthesis of carbohydrate cell wall components, such as cellulose and callose. The Arabidopsis thaliana genome contains two putative genes encoding UGPase, AtUGP1 and AtUGP2. These genes are expressed in all organs. In order to determine the role of UGPase in vegetative and reproductive organs, we employed a reverse genetic approach using the T-DNA insertion mutants, atugp1 and atugp2. Despite a significant decrease in UGPase activity in both the atugp1 and atugp2 single mutants, no decrease in normal growth and reproduction was observed. In contrast, the atugp1/atugp2 double mutant displayed drastic growth defects and male sterility. At the reproductive phase, in the anthers of atugp1/atugp2, pollen mother cells developed normally, but callose deposition around microspores was absent. Genes coding for enzymes at the subsequent steps in the cellulose and callose synthesis pathway were also down-regulated in the double mutant. Taken together, these results demonstrate that the AtUGP1 and AtUGP2 genes are functionally redundant and UGPase activity is essential for both vegetative and reproductive phases in Arabidopsis. Importantly, male fertility was not restored in the double knockout mutant by an application of external sucrose, whereas vegetative growth was comparable in size with that of the wild type. In contrast, an application of external UDP-glucose recovered male fertility in the double mutant, suggesting that control of UGPase in carbohydrate metabolism is different in the vegetative phase as compared with the reproductive phase in A. thaliana.
AB - UDP-glucose pyrophosphorylase (UGPase) is an important enzyme in the metabolism of UDP-glucose, a precursor for the synthesis of carbohydrate cell wall components, such as cellulose and callose. The Arabidopsis thaliana genome contains two putative genes encoding UGPase, AtUGP1 and AtUGP2. These genes are expressed in all organs. In order to determine the role of UGPase in vegetative and reproductive organs, we employed a reverse genetic approach using the T-DNA insertion mutants, atugp1 and atugp2. Despite a significant decrease in UGPase activity in both the atugp1 and atugp2 single mutants, no decrease in normal growth and reproduction was observed. In contrast, the atugp1/atugp2 double mutant displayed drastic growth defects and male sterility. At the reproductive phase, in the anthers of atugp1/atugp2, pollen mother cells developed normally, but callose deposition around microspores was absent. Genes coding for enzymes at the subsequent steps in the cellulose and callose synthesis pathway were also down-regulated in the double mutant. Taken together, these results demonstrate that the AtUGP1 and AtUGP2 genes are functionally redundant and UGPase activity is essential for both vegetative and reproductive phases in Arabidopsis. Importantly, male fertility was not restored in the double knockout mutant by an application of external sucrose, whereas vegetative growth was comparable in size with that of the wild type. In contrast, an application of external UDP-glucose recovered male fertility in the double mutant, suggesting that control of UGPase in carbohydrate metabolism is different in the vegetative phase as compared with the reproductive phase in A. thaliana.
KW - Arabidopsis thaliana
KW - Callose synthesis
KW - Carbohydrate metabolism
KW - Male sterility
KW - UDP-glucose
KW - UGPase
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U2 - 10.1093/pcp/pcq057
DO - 10.1093/pcp/pcq057
M3 - Article
C2 - 20435647
AN - SCOPUS:77953607619
VL - 51
SP - 981
EP - 996
JO - Plant and Cell Physiology
JF - Plant and Cell Physiology
SN - 0032-0781
IS - 6
ER -