In Arabidopsis thaliana, the invertase inhibitors AtC/VIF1 and 2 exhibit distinct target enzyme specificities and expression profiles.
Plant cell wall (CWI) and vacuolar invertases (VI) play important roles in carbohydrate metabolism, stress responses and sugar signaling. Addressing the regulation of invertase activities by inhibitor proteins (C/VIF, cell wall/vacuolar inhibitor of fructosidase), we have identified two C/VIFs from Arabidopsis thaliana. AtC/VIF1 showed specific inhibition of VI activity, whereas AtC/VIF2 inhibited both, CWI and VI. Expression analysis revealed that expression of AtC/VIF1 was restricted to specific organs, AtC/VIF2, however, was weakly expressed throughout plant development. Promoter::GUS transformants confirmed pronounced differences of tissue/cell type-specific expression between both isoforms. Growth of an AtC/VIF1 T-DNA KO mutant was unaffected, but VI activity and hexose content were slightly increased.
Heidelberg Institute of Plant Sciences (HIP), Im Neuenheimer Feld 360, D-69120 Heidelberg, Germany.
Manuela
M
Link
Thomas
T
Rausch
Steffen
S
Greiner
D017360:Arabidopsis / Q000737:chemistry / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D004791:Enzyme Inhibitors / Q000378:metabolism*; D017353:Gene Deletion; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D006601:Hexoses / Q000032:analysis / Q000737:chemistry; D009928:Organ Specificity; D018515:Plant Leaves / Q000737:chemistry / Q000235:genetics; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D043324:beta-Fructofuranosidase / Q000037:antagonists & inhibitors* / Q000378:metabolism
D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D004791:Enzyme Inhibitors; D006601:Hexoses; D020033:Protein Isoforms; D018749:RNA, Plant; C036483:T-DNA; D043324:beta-Fructofuranosidase