Showing papers on "Plant physiology published in 1984"
TL;DR: Jasmonic acid was detected in several Leguminosae plants and a number of species belonging to nine other Angiospermae families and highest amounts occurred in fruit parts, but it was found also in flowers and vegetative plant parts, e.g. leaves, stems, and germs.
Abstract: The natural occurrence of jasmonic acid and its methyl ester in plants has been studied using different methods such as GC, GC-MS, HPLC, radioimmunoassay, and bioassay. Jasmonic acid was detected in several Leguminosae plants and a number of species belonging to nine other Angiospermae families. Highest amounts occurred in fruit parts, especially the immature pericarp, but it was found also in flowers and vegetative plant parts, e.g. leaves, stems, and germs. Young apple fruits contain both jasmonic acid and methyl jasmonate, and in Douglas fir, the only Gymnospermae species studied, only the methyl ester could be detected. Jasmonic acid is discussed as an endogenous plant growth regulator widely distributed in higher plants.
283 citations
TL;DR: No root systems in nature are without a microbial population, and these may be free-living or symbiotic.
Abstract: No root systems in nature are without a microbial population.These may be free-living or symbiotic.
119 citations
TL;DR: Vanadium increased plant height, weight, number of leaves, and number of flowers, and enhanced chlorophyll formation and Fe metabolism in tomato plants, and increased the Hill reaction activity of isolated chloroplasts.
Abstract: Distribution of vanadium and its influence on growth, chlorophyll formation and certain aspects of iron metabolism were studied in tomato plants (Lycopersicon esculentum Mill. cv. ‘Walter). Vanadium in the nutrient solution increased plant height, weight, number of leaves, and number of flowers. Vanadium also enhanced chlorophyll formation and Fe metabolism in tomato plants, and increased the Hill reaction activity of isolated chloroplasts.
25 citations
8 citations
01 Jan 1984
TL;DR: In this article, the authors investigated the relationship between leaf carbohydrate partitioning and nodule activity in soybeans under natural conditions and the irradiance level required to allocate sufficient carbohydrate to obtain maximum rates of 0 2 1 1 1 2 reduction.
Abstract: Diurnal trends in leaf carbohydrate partitioning and nodule activity in soybeans under natural conditions and the irradiance level required to allocate sufficient carbohydrate to obtain maximum rates of ^ ( 0 2 1 1 2 ) reduction were studied. Soybeans grown outdoors maintained constant levels of soluble carbohydrates in the leaves and constant rates of ^ fixation and root + nodule respiration when root temperature was kept constant but shoot temperature varied. When plants were subjected -2 to a 40-hour dark period, then exposed to 200 to 1000 pE m 1 2 1 sec , 200 pE m sec resulted in maximum leaf soluble carbohydrate and nodule activity. Results suggest that nodule activity is controlled by carbohydrate partitioning in the shoot and support the concept of an environment-mediated programming of carbohydrate distribution. Carbon and nitrogen limitations to growth of symbiotically-grown soybean plants were assessed by examining growth characteristics of plants grown under low irradiance in a greenhouse and high irradiance outdoors and provided 0.0, 2.0, 6.0 or 12.0 mM NO^. Under low irradiance, supplementing ^ fixation with 2.0 mM NO^ resulted in relative growth rates (RGR), leaf area ratios (LAR) and net assimilation rates (NAR) very similar to plants supplied 12.0 mM NO^. As a result, total plant dry weight and leaf area of these two treatments were
2 citations
01 Jan 1984
TL;DR: Probing leaf nitrogen metabolism and translocation of photoassimilates in intact higher plants is complicated both by the compounds which are available for research, and by traditional plant physiology and biochemistry.
Abstract: Probing leaf nitrogen metabolism and translocation of photoassimilates in intact higher plants is complicated both by the compounds which are available for research, and by traditional plant physiology and biochemistry which argues, correctly, that the primary flow of nitrogenous compounds into a plant is via the root system and then into the leaf tissue.
2 citations
01 Jan 1984
TL;DR: It is clear that leaf protein composition is an essential data in plant physiology and ecology or in plant breeding and agriculture.
Abstract: The membranous proteins of lamellae and the soluble proteins of chloroplast stroma account for nearly all the proteins in leaves (Joyard,1979). Agriculture productivity relies on these proteins in different ways. First, the biosynthesis of sugars from carbon dioxide, water and light, depends on them since they are building blocks of the photosynthetic apparatus. Second, they are part of several crops such as vegetables, fodder or leaf protein concentrate; the quality and value of these crops depend obviously on leaf proteins. It is thus clear that leaf protein composition is an essential data in plant physiology and ecology or in plant breeding and agriculture.
1 citations
1 citations
01 Jan 1984
TL;DR: Evidence has revealed in recent years that also this carbon reduction phase requires light, namely for activation of certain photosynthetic enzymes, which have either low or even no activity in the dark.
Abstract: Many textbooks of biochemistry and plant physiology still restrict the requirement of light in photosynthesis to the so-called “light reactions”, the reactions of the photosynthetic electron transport, by which light energy is converted into chemical energy in the form of ATP and NADPH. According to this view the so-called “dark reactions”, the conversion of CO2 to carbohydrates and other products ofphotosynthesis, proceed by a series of light independent enzyme catalyzed reactions. Evidence has revealed in recent years, however, that also this carbon reduction phase requires light, namely for activation of certain photosynthetic enzymes, which have either low or even no activity in the dark. In addition, several enzymes of the oxidative carbohydrate metabolism seem to be inhibited by light during photosynthesis. The mechanism for this light regulation of enzymes has been elucidated to some extent. Besides responses of several enzymes to changes in pH and Mg2+ the ratio of certain reduced to oxidized cofactors plays an important regulatory role. Two systems have been proposed for such mediation by redox levels, the ferredoxin/thioredoxin and the LEM system (for reviews see Buchanan, 1980 and Anderson, 1979, resp.).