RESUMO
Senescence is the final stage in the life history of a leaf, whereby plants relocate nutrients from leaves to other developing organs. Recent efforts have begun to focus on understanding the network-based molecular mechanism that incorporates various environmental signals and leaf age information and involves a complex process with the coordinated actions of multiple pathways. Here, we identified a novel participant, named LSR1 (Leaf Senescence Related 1), that involved in the regulation of leaf senescence. Loss-of-function lsr1-1 mutant showed delayed leaf senescence whereas the overexpression of LSR1 accelerated senescence. LSR1 encodes a lipid transfer protein, and the results show that the protein is located in chloroplast and intercellular space. The LSR1 may be involved in the regulation of leaf senescence by transporting lipids in plants.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Humanos , Lipídeos , Folhas de Planta/metabolismo , Senescência Vegetal , Plantas Geneticamente Modificadas/metabolismoRESUMO
Based on the color reaction of 2-(2-quinolinylazo)-5-diethylaminoaniline (QADEAA) with palladium(II) and the solid phase extraction of its colored complex with MCI-GEL reversed phase cartridge, a new method for the determination of trace palladium was established. In the presence of 0.2-2.0 mol x L(-1) of hydrochloric acid solution and CTMAB medium, QADEAA reacts with palladium(II) to form a stable 2:1 complex. The colored complex can be enriched by MCI-GEL reversed phase cartridge, and the retained chelates was then eluted by acetone. The eluant was determined by spectrophotometry at 615 nm. Beer's law is obeyed in the range of 0.01-1.5 mg x L(-1). This method was applied to the determination of palladium with good results.
