Colleters produce a secretion composed of hydrophilic and/or lipophilic substances which lubricates and protects the shoot apical meristem against biotic abiotic agents. Little attention has been given to these structures in Clusiaceae. In present study, structure development leaf colleters Clusia criuva subsp. were described variations exudate composition at different stages identified. The sa...

An enzyme system is described which oxidizes 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene under physiological conditions. It comprises linoleic acid, pyridoxal phosphate, manganese, and lipoxygenase (linoleate:oxygen oxidoreductase, EC 1.13.11.12). It requires oxygen and is specific for manganese; it can operate but only with greatly reduced yield in the absence of pyridoxal phosphat...

Colorless nonfluorescent chlorophyll (Chl) catabolites (NCCs) are formyloxobilin-type phyllobilins, which are considered the typical products of Chl breakdown in senescent leaves. However, in degreened leaves of some plants, dioxobilin-type Chl catabolites (DCCs) predominate, which lack the formyl group of the NCCs, and which arise from Chl catabolites by oxidative removal of the formyl group b...

The links between internal nitrogen recycling through the process of resorption from senescing leaves, whole-plant resource-use strategies and performance remain elusive. Indeed, tests such potential linkages are hampered by classical evaluation plant efficiency (REN) based on ‘snapshots’ leaf concentration adult senescent leaves. We significantly increased resolution for measuring non-destruct...

Recently, the so-called "plant factory with artificial lighting" (PFAL) approach has been developed to provide safe and steady food production. Although PFALs can produce high-yielding and high-quality plants, the high plant density in these systems accelerates leaf senescence in the bottom (or outer) leaves owing to shading by the upper (or inner) leaves and by neighboring plants. This decreas...

Blumea balsamifera, also named Ainaxiang, is widely used as an ancient medicinal herb in tropical and subtropical Asia. It is rich in essential oils. In this work the essential oils of B. balsamifera from different plant organs and in different months were extracted, and then analyzed by gas chromatography-mass spectrometry. The results showed that essential oil yield of young leaves was the hi...

Leaves from 145-year-old and 44-year-old beech trees were harvested during 1991-1993. Chlorophyll (Chi) and redox components of the thylakoid membrane, including P-700, cytochrome / (C yt/) and D, protein, were determined with the following results. Chi a + b, P-700 and C y t/p er unit of fresh weight (FW), dry weight (DW ) and leaf area (LA ) increase significantly during leaf development. Thi...

Although the loss of green color in senescent leaves and ripening fruits is a spectacular natural phenomenon, research on chlorophyll breakdown has been largely neglected until recently. This review summarizes knowledge about the fate of chlorophyll in degreening tissues that has been gained during the past few years. Structures of end- and intermediary products of degradation as well as the bi...

We examined the effects of elevated CO2 concentration ([CO2]) on leaf demography, late-season photosynthesis and leaf N resorption of overstory sweetgum (Liquidambar styraciflua L.) trees in the Duke Forest Free Air CO2 Enrichment (FACE) experiment. Sun and shade leaves were subdivided into early leaves (formed in the overwintering bud) and late leaves (formed during the growing season). Overal...