A method is described for relating the age of a cereal leaf cell to its distance from the leaf base. The rates of chlorophyll synthesis per plastid in the first leaf of light-grown and of greening etiolated seedlings of wheat (Triticum aestivum, var. Maris Dove) increase with cell age. Normally developing plastids of light-grown wheat take over 24 hours to reach the chlorophyll a/b ratio charac...

abstract- the evaluation of leaf area and leaf nutritional value is important for crop growth modeling and estimations of its performance. the purpose of this study was to use image processing techniques to develop an economical method to ease the assessment of nutrient status and leaf area (la) of plants and to compare the outcomes of this method with linear models. leaf area and leaf chloroph...

Chlorophyll breakdown occurs in different green plant tissues (e.g. during leaf senescence and in ripening fruits). For different plant species, the PHEOPHORBIDE A OXYGENASE (PAO)/phyllobilin pathway has been described to be the major chlorophyll catabolic pathway. In this pathway, pheophorbide (i.e. magnesium- and phytol-free chlorophyll) occurs as a core intermediate. Most of the enzymes invo...

Chlorophyll breakdown occurs in different green plant tissues (e.g. during leaf senescence and in ripening fruits). For different plant species, the PHEOPHORBIDE A OXYGENASE (PAO)/phyllobilin pathway has been described to be the major chlorophyll catabolic pathway. In this pathway, pheophorbide (i.e. magnesiumand phytol-free chlorophyll) occurs as a core intermediate. Most of the enzymes involv...

Leaf chlorophyll content is an important variable for agricultural remote sensing because of its close relationship to leaf nitrogen content. The triangular greenness index (TGI) was developed based on the area of a triangle surrounding the spectral features of chlorophyll with points at (670 nm, R670), (550 nm, R550), and (480 nm, R480), where R is the spectral reflectance at wavelengths of 67...

Green leaves face two fundamental challenges (i.e., carbon fixation and stress tolerance) during their lifespan. However, the relationships between leaf production potential and leaf tolerance potential have not been explicitly tested with a broad range of plant species in the same environment. To do so, we conducted a field investigation based on 107 woody plants grown in a common garden and c...

The purpose of this paper was to investigate the early water stress in maize using leaf-level measurements of chlorophyll fluorescence and temperature. In this study, a series of diurnal measurements, such as leaf chlorophyll fluorescence (Fs), leaf spectrum, temperature and photosynthetically active radiation (PAR), were conducted for maize during gradient watering and filled watering experime...

Leaf and canopy nitrogen (N) status relates strongly to leaf and canopy chlorophyll (Chl) content. Remote sensing is a tool that has the potential to assess N content at leaf, plant, field, regional and global scales. In this study, remote sensing techniques were applied to estimate N and Chl contents of irrigated maize (Zea mays L.) fertilized at five N rates. Leaf N and Chl contents were dete...

The objective of this study was to determine xanthophyll cycle pool size and composition in response to N status and their relationships to non-photochemical quenching in apple leaves. Bench-grafted Fuji/M.26 trees were fertilized with different N concentrations (0-20 mM) in a modified Hoagland's solution for 6 weeks to create a wide range of leaf N status (1-4.4 g m(-2)). Chlorophyll content, ...

Activities of phosphoriboisomerase, phosphoribulokinase, and ribulose 1,5-diphosphate carboxylase, protein content, and chlorophyll accumulation in dark-grown barley seedlings were measured before and after illumination. Enzymatic activities, levels of soluble protein, and accumulation (upon illumination) of chlorophyll in leaves declined from tips toward the base. In response to increasing tim...