In order to study of the effect of priming and salinity on physiological and chemical characteristics of wheat(Triticum aestivum L.), an experiment was carried out at the Experimental Farm of Shiraz University. Results showedthat primed plants significantly reduced its gas exchanges by accelerating senescence under a series of salt stress,which became more serious along with the increasing of s...

The expression of several Arabidopsis senescence-associated genes (SAGs) was found to be upregulated during leaf development of the onset of leaf death 9 mutant under standard growth conditions. Treatment of the mutant with ethylene resulted in a severe senescence response both phenotypically as well as on transcript level. A RNAi-based strategy to downregulate the expression of a SAG encoding ...

We analysed the level of polyamines (PAs) bound to thylakoids and the level and activity of thylakoid transglutaminases throughout barley leaf senescence, retarded by kinetin. The level of PAs bound to thylakoids changed in senescing barley leaves: bound putrescine (PU) and spermidine (SD) increased throughout senescence, whereas bound spermine (SM) decreased. Kinetin diminished the increase in...

Sequential and monocarpic senescence are observed at vegetative and reproductive stages, respectively. Both facilitate nitrogen (N) remobilization and control the duration of carbon (C) fixation. Genetic and environmental factors control N and C resource allocation to seeds. Studies of natural variation in Arabidopsis thaliana revealed differences between accessions for leaf senescence phenotyp...

It has been proposed that delayed leaf senescence can extend grain filling duration and thus increase yields in cereal crops. We found that wheat (Triticum aestivum) NAM RNAi plants with delayed senescence carried out 40% more flag leaf photosynthesis after anthesis than control plants, but had the same rate and duration of starch accumulation during grain filling and the same final grain weigh...

Senescence is the last phase of the plant life cycle and has an important role in plant development. Degradation of membrane lipids is an essential process during leaf senescence. Several studies have reported fundamental changes in membrane lipids and phospholipase D (PLD) activity as leaves senesce. Suppression of phospholipase Dα1 (PLDα1) retards abscisic acid (ABA)-promoted senescence. Howe...

BACKGROUND AND AIMS Water is an increasingly scarce resource that limits crop productivity in many parts of the world, and the frequency and severity of drought are predicted to increase as a result of climate change. Improving tolerance to drought stress is therefore important for maximizing future crop yields. The aim of this study was to compare the effects of drought on soybean (Glycine max...

Spring geophytes produce larger storage organs and present delayed leaf senescence under lower growth temperature. Bulb and leaf carbon metabolism were investigated in Erythronium americanum to identify some of the mechanisms that permit this improved growth at low temperature. Plants were grown under three day/night temperature regimes: 18/14 °C, 12/8 °C, and 8/6 °C. Starch accumulated more sl...

Abstract Leaf senescence, the last stage of leaf development, is a type postmitotic senescence and characterized by functional transition from nutrient assimilation to remobilization which essential for plants’ fitness. The initiation progression are regulated variety internal external factors such as age, phytohormones, environmental stresses. Significant breakthroughs in dissecting molecular ...

Leaf exchange is an abrupt phenological event that drastically modifies the morphology and physiology of the aerial portion of the plant. We examined if water and osmolyte differences between old leaves and new organs trigger leaf exchange, and whether the differences are closely linked to the resource resorption process in senescing leaves. We monitored concentrations of osmolyte, water, non-s...