Seasonal variation of proteins and amino acids in apple flower buds (Malus pumila Mill., cv. McIntosh/M7)

Cultural and Environmental Factors Associated with Winter Injury to Apple in Northern Eastern Canada

“…While there have been many studies of cold resistance and metabolic change in Malus woody tissue, (Brown, 1978;Khanizadeh et al, 1989aKhanizadeh et al, , 1989bKhanizadeh et al, , 1992aKhanizadeh et al, , 1994Li, 1987;Sakai and Larcher, 1987), types of freezing injury (Granger, 1981;Weiser, 1970); breeding hardy cultivars or using hardy intermediate framestocks (Granger et al, 1991(Granger et al, , 1992(Granger et al, , 1993Spangelo et al, 1974;Stushnoff, 1972); inactivating ice-nucleating bacteria (Lindow and Connell, 1984;Lindow et al, 1989); use of chemical cryoprotectants (Ketchie and Murren, 1976); cultural manipulation to slow growth and induce wood maturity in early autumn (Collins et al, 1978;Stang et al, 1978); and autumn sprays of growth regulators to delay bud break, no study has been done of the relationship between the cultivar, rootstock, environmental conditions and cultural practices in relation to winter injury in Quebec orchards.…”

Dynamic changes of secondary metabolites and tyrosinase activity of Malus pumila flowers

“…At present, the dynamic change of M. pumila is mainly focused on fruits, leaves and branches. However, there are fewer investigations on the dynamic change of M. pumila flowers, except for the dynamic changes of amino acids and protein [18]. In order to make full use of M. pumila resources, the dynamic changes of secondary metabolites and tyrosinase activity were investigated during M. pumila flowers blooming.…”

Misuse of the Kjeldahl Method for Estimating Protein Content in Plant Tissue

“…Therefore, the conversion factor of 6.25 is inexact and results in overestimation of total protein in most plant tissue (Khanizadeh et al, 1992b;Milton and Dintzis, 1981). We believe that a specific conversion factor should be calculated for each tissue to estimate total protein content accurately, given that total nonprotein N content varies from plant to plant, between different tissues on the same plant, and even in the same tissue at different stages of growth and development (Jones, 1931Khanizadeh et al, 1989;Milton and Dintzis, 1981). While the factor of 6.25 is widely used for many plant tissues, specific factors for total protein determination have been developed for many crops.…”

“…This method seems the most reliable for plant tissues and is independent of the type of protein or tissue. It can be used for fresh or dried materials with very low protein content (Horstmann, 1979;Khanizadeh et al, 1989;Marks et al, 1985;Moore and Stein, 1948;Spies, 1957). It is suitable for soluble (i.e., free amino acids, oligopeptides, amino sugars) and insoluble proteins (i.e., cell wall glycoproteins) that are present in large amounts in all plant tissue (Heidelbaugh et al, 1975; Accurate plant protein analysis is difficult, primarily because of the small amounts of proteins present in the tissue and partly due to the interference of other complex plant constituents (Agustí and Beltrán, 1982;Khanizadeh et al, 1989Khanizadeh et al, , 1992aMarks et al, 1985;Robinson, 1979).…”

“…1 Horstmann, 1979;Khanizadeh et al, 1989). An added advantage of amino acid analysis using the ninhydrin reaction is the lack of interference by phenolics, tannins, and lignins, which are universally present in plants, often in high concentrations (Khanizadeh et al, 1989(Khanizadeh et al, , 1992bLommis, 1974;Marks et al, 1985). Furthermore, free amino acid content can be measured using the unhydrolyzed methanol extracts of plant samples (Marks et al, 1985).…”