In 1955 Osborne reported that petiole sections cut from senescent leaves of any one of many species could speed the abscission of excised and debladed bean petioles (5). The sections from senescent leaves speeded abscission if directly attached or if one attached an agar block on which they had stood for 24 hours. She "proposed that leaf abscissions may be controlled not only by endogenous auxi...

Extended x-ray absorption fine structure measurements were performed on frozen hydrated samples of the cadmium (Cd)/zinc (Zn) hyperaccumulator Thlaspi caerulescens (Ganges ecotype) after 6 months of Zn(2+) treatment with and without addition of Cd(2+). Ligands depended on the metal and the function and age of the plant tissue. In mature and senescent leaves, oxygen ligands dominated. This resul...

This study aimed to elucidate the effects of periphyton on the microprofiles of oxygen (O2), pH, and oxidation-reduction potential around the stems and leaves of a submerged macrophyte Potamogeton malaianus and on the plant growth in the eutrophic shallow Taihu Lake, China. The microprofiles were measured using a motorized microprofiling system equipped with microsensors. The leaf age of the ma...

Levels of cytokinins and abscisic acid (ABA) and the expression of senescence-related genes were investigated in two maize (Zea mays L.) cultivars of different senescence type, cv. P3845 (stay-green) and cv. Hokkou 55 (earlier senescent), in a field study. The delay in leaf senescence in P3845 was correlated with increased levels of chlorophyll and nitrogen and a higher photon-saturated photosy...

The early light-induced proteins (Elips) in higher plants are nuclear-encoded, light stress-induced proteins located in thylakoid membranes and related to light-harvesting chlorophyll (LHC) a/b-binding proteins. A photoprotective function was proposed for Elips. Here we showed that after 2 h exposure of Arabidopsis (Arabidopsis thaliana) leaves to light stress Elip1 and Elip2 coisolate equally ...

Leaf senescence is an important biological process that contributes to grain yield in crops. To study the molecular mechanisms underlying natural leaf senescence, we harvested three different developmental ear leaves of maize, mature leaves (ML), early senescent leaves (ESL), and later senescent leaves (LSL), and analyzed transcriptional changes using RNA-sequencing. Three sets of data, ESL vs....

We studied the microbial flora in decomposing mangrove leaves in relation to changes in nitrogen and tannin levels, and in penaeid prawn assemblages. Senescent leaves of two mangrove species (Rhizophora apiculata and Avicennia marina) kept in nylon bags, were separately immersed for 80 days in five tanks full of mangrove water. A known amount of decomposing leaves was collected every ten days f...

Analyses were made of chlorophyll a and b and fatty acids (18:3, 18:2, 18:1, 18:0, 16:2, 16:1, and 16:0) of greening and senescing leaf tissue. Those dark-grown tissues given a prior treatment of red, far red, or red followed by far red light showed similar increases in chlorophylls and linolenate (18:3) when exposed to continuous white light. In contrast, green barley (Hordeum vulgare L.) leav...

The joint interpretation of phenology and nutritional metabolism provides important data on plant tissues reactivity and the period of gall induction. A population of Aspidosperma macrocarpon (Apocynaceae) with leaf galls induced by a Pseudophacopteron sp. (Psylloidea) was studied in Goiás state, Brazil. Assuming the morphological similarity between host leaves and intralaminar galls, a gradien...