ISSN:0190-4167    

DOI:10.1080/01904168809363827

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Iron nutrition in higher plants is an extremely complex process, but significant progress is occurring in several areas. This paper reviews some of the phenomena which span the activities of iron availability to plant roots, transmembrane uptake and translocation within the plant. Specific attention is directed toward the iron transport problems and the orientation of future research.

ISSN:0190-4167    

DOI:10.1080/01904168809363828

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Root secretions of Fe‐stressed barley cultivars were subjected to TLC and HPLC examination for mugineic acid (MA) and analogous chelators (MAS). The results indicates that cv. Minorimugi secreted MA as the major component and 2'‐deoxymuglneic acid (DMA) as the minor one, whereas cv. Rikuzenmugi secreted mainly DMA and lesser amount of MA. MAS of these cultivars were identified by1H‐NMR spectra. TLC examination suggested that cv. Tochigi goldenmelon, a two‐rowed barley variety, secreted chiefly an unidentified chelator, together with trace amounts of MA and DMA. The unidentified chelator was determined spectroscopically to be 3‐epihydroxymugineic acid (epi‐HMA).

ISSN:0190-4167    

DOI:10.1080/01904168809363829

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Several chelators Including EDTA, DTPA, deferriferrioxamine B (FOB), mugineic acid (MA), and 2'‐deoxymugineic acid (DMA) were tested for their ability to extract Fe from different soil samples. MA and DMA exhibited the highest efficiency of Fe extraction, especially at alkaline pH. Other chelators proved to be poor in solubilizing Fe; EDTA and DTPA solubilized either Al or Ca preferentially depending on the soil pH, while FOB extracted mainly Al at both acid and alkaline pH's. Mugineic acids, while proved highly efficient in extracting Fe from calcareous, high pH soils, appeared vulnerable to microbial decomposition.

ISSN:0190-4167    

DOI:10.1080/01904168809363830

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The peptides appearing in barley roots related to phytosiderophore synthesis or absorption under Fe‐deficiency were analyzed. Two varieties of barley were used. ‘Ehimehadaka NO.11secreted 3‐epihydroxymugineic acid and traces of 3‐hydroxymugineic acid, mugineic acid and 2'‐deoxymugineic acid. ‘Minorimugi’ secreted mugineic acid, and traces of 3‐epihydroxymugineic acid and 2'‐deoxymugineic acid. Peptides in supernatant fractions of Fe‐deficient roots were detected by35s‐fluorography and/or by silver‐stain on two dimensional electrophoresis. In the case of ‘Ehimehadaka NO.1’, two peptides (m.w. 53kD, pI 6.6) and (53kD, 6.7) by fluorography, and (52kD, 6.9), (31kD, 6.6) and (30kD, 6.8) by silver‐stain were detected. In the case of ‘Minorimugi’, two peptides (53kD, 6.6) and (53kD, 6.7) by fluorography, (31kD, 6.6) and (30kD, 6.8) by silver‐stain were detected. The synthesis of the 53kD peptide was strongly related to the secretion amount of phytosiderophores. Whereas the 52kD related to 3‐epihydroxymugineic acid synthesis. The 31kD and 30kD may be peptides related to the absorption mechanism of FeIII‐phytosiderophore chelate by the roots.

ISSN:0190-4167    

DOI:10.1080/01904168809363831

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Graminaceous species (grasses) have different mechanisms for mobilization and uptake of iron (Fe) than non‐graminaceous plant species. Roots of Fe deficient grasses release phytosiderophore compounds which greatly enhance mobilization and uptake of Fe. Studies were conducted to determine Fe uptake by various sorghum (Sorghum bicolor(L.) Moench) genotypes differing in age (10–22 days) and degrees of Fe deficiency chlorosis. For comparison, barley (Hordeum vulgareL. cv Europa) was used as a grass species with high resistance to Fe deficiency chlorosis.

ISSN:0190-4167    

DOI:10.1080/01904168809363832

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This work was to study the characteristics of root exudate from Fe‐deficient and nondeficient corn plants as well as to study the ability of corn to utilize Fe‐III from different sources.

ISSN:0190-4167    

DOI:10.1080/01904168809363833

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Seedlings of tomato and tobacco were V‐grafted reciprocally and intraspecifically and cultured for 22 days in 2‐liter containers of nutrient solution with normal or no iron. The pH of solutions containing iron increased slightly, while the pH of solutions with no iron decreased. There was little decrease in the pH of tomato grafts on tomato, while the pH of other combinations decreased from 1.5 to 3.1 pH units. Riboflavin concentrations in nutrient solution were highest with tobacco on tobacco, and were about one‐third less with tomato on tobacco. The riboflavin values for tobacco on tomato and tomato on tomato were barely detectable like those for plants supplied with iron. Roots of iron‐deficient tobacco plants at harvest contained much more total riboflavin than roots of iron‐deficient tomato plants and roots of iron‐supplied plants contained less total riboflavin than iron‐deficient plants. Total riboflavin in roots of tobacco plants exceeded that in roots of tomato plants. The total riboflavin concentrations in leaves of iron‐deficient plants were elevated in plants on tobacco roots but not in plants on tomato roots. At harvest, after some regreening, tobacco leaves on tomato roots were more chlorotic than when on tobacco roots and tomato leaves on tomato plants were more chlorotic than when on tobacco roots. Results suggest that the roots are the site for the increased synthesis of the riboflavin in tobacco. Riboflavin may partially substitute for iron in roots and leaves.

ISSN:0190-4167    

DOI:10.1080/01904168809363834

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

After labelling a calcareous soil with59Fe, the mobilization of labelled Fe by root exudates of Fe‐deficient barley plants (Hordeum vulgareL.) was studied in vitro at pH 7.4 in short term experiments of up to 48 h. These root exudates contain chelators (phytosiderophores) which form stable FeIII chelates (ferrated phytosiderophores) . Compared to the control (CaSO4), the mobilization rate of labelled Fe within the first 16 h. was increased by phytosiderophores (10‐5M) by a factor between 10 and 20.

ISSN:0190-4167    

DOI:10.1080/01904168809363835

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The potential production loss attributable to Fe‐deficiency chlorosis in soybean [Glycine max(L.) Merr.] grown on calcareous soil is sufficient to justify the development of high‐yielding, Fe‐efficient soybean cultivars in several states. Alternative breeding methods and screening techniques for the development of high‐yielding, Fe‐efficient cultivars and parental germplasm were studied. In the breeding methodology studies, populations derived from crosses of lower yielding, Fe‐efficient X high‐yielding, Fe‐inefficient parents had lower mean yields but greater average Fe‐efficiency than populations derived by backcrossing to the high‐yielding parent. Phenotypic correlations between the yield of breeding lines on noncalcareous soil and their Fe‐efficiency on calcareous soil were positive or not significant, indicating that selection of high‐yielding, Fe‐efficient cultivars should be possible. In a recurrent selection program to improve the Fe‐efficiency of a population, a nutrient solution system is used to obtain adequate chlorosis for the selection of superior lines for recombination. Correlations between field chlorosis ratings and those obtained in nutrient solution were highly favorable. Lines superior to the highly Fe‐efficient genotype A7 have been identified and released to research scientists.

ISSN:0190-4167    

DOI:10.1080/01904168809363836

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor