Nucleases activities during French bean leaf aging and dark-induced senescence.

摘要: Abstract During leaf senescence resources are managed, with nutrients mobilized from older leaves to new sink tissues. The latter implies a dilemma in terms of resource utilization, the should increase seed quality whereas delay improve yield. Increased knowledge about nutrient recycling during could lead advances agriculture and improved quality. Macromolecules include proteins nucleic acids. Although acids have been less well studied than protein degradation, they possible reservoirs nitrogen phosphorous. present study investigated nuclease activities gene expression patterns five members S1/P1 family French bean ( Phaseolus vulgaris L. cv.)Page: 2 senescence. An in-gel assay was used detect activity natural dark-induced senescence, single-stranded DNA (ssDNA) as substrate. results revealed two nucleases (glycoproteins), molecular masses 34 39 kDa senescent leaves. were higher at neutral an acidic pH. EDTA treatment inhibited nucleases, addition zinc resulted recovery these activities. Both able use RNA double-stranded (dsDNA) substrates, although their low when dsDNA In addition, ribonucleases 14 16 kDa, both which only utilize substrate, detected Two family, PVN2 PVN5 , expressed under experimental conditions, suggesting that genes involved glycoproteins similar conditions.