ISSN:0190-4167    

DOI:10.1080/01904168209362953

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Fe‐deficiency chlorosis has been recognized since 1844 (Gris) and was the first plant nutrient deficiency to be investigated. It is a reflection of the continuing importance of iron nutrition problems in major crops worldwide that anybody interested in any aspect of plant nutrition cannot but be aware of them, whether as Fe‐deficiency or Fe‐toxicity. This paper does not purport to be a review, but rather attempts to sketch in the dimensions of the problem.

ISSN:0190-4167    

DOI:10.1080/01904168209362954

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Iron (Fe) deficiency is a major problem limiting growth and production of many crop plants grown in the Great Plains. The soils of this area are generally neutral or alkaline and usually have underlying calcareous deposits. Water supply is usually limited in this area, so crops like sorghum and soybeans are often grown. With some exceptions, the Fe deficiency problem generally appears to increase from north to south and is most severe in sorghum and soybeans. Sorghum and soybean cannot be grown in many areas because of their susceptibility to Fe deficiency. Over 90% of the sorghum production in the U.S. is in the Great Plains, thus Fe deficiency in sorghum is important. Alleviation of Fe deficiency is expensive and difficult. Practical, economical, and longlasting or permanent solutions for overcoming the problem are needed. Information on existing problems, on research now being conducted, and on future research needs for Fe deficiencies in plants grown in the Great Plains has been presented.

ISSN:0190-4167    

DOI:10.1080/01904168209362955

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

It is of value to periodically consider the iron metabolism and nutrition of the vivitude (the community of all living things) in order to see the unifying themes nature has employed in bringing about the assimilation, transport, utilization and storage of this biologically precious metal. Humans and plants are of particular interest since in both groups nutritional iron deficiency is of serious concern. In both groups the problem is most often related to the bioavailability of iron in the nutritive substrate: both soil and foods generally contain sufficient iron to meet nutritional demands, yet, that iron is largely bound in forms that make it unavailable for assimilation. This paper considers the biological responses that various organisms, particularly plants and humans, make to iron deprivation (and overload) and the means used for the internal management of iron.

ISSN:0190-4167    

DOI:10.1080/01904168209362956

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Iron deficiency has long been considered to be the most difficult of nutrient deficiencies in plants to understand and to correct. After the landmark discovery in 1843 that lime‐induced chlorosis was a form of iron deficiency, progress was slow for the next 100 years. Many, but not all, of the scientific giants who made significant progress on understanding iron chlorosis and iron physiology in plants in the 1940's and 1950's have passed away. Thome was certain that ferrous iron was the key to understanding the disorder. Kliman had suggested uptake of Pe in the ferrous form. Iljin found that iron chlorotic leaves had high levels of free amino acids, high levels of citrate and total organic acids, were high in P and K and low in Ca concentrations. These are the criteria that generally identify iron chlorosis. Shive and his students found an Fe‐Mn interaction through which Fe deficiency can be induced. Warm found that lime‐induced chlorosis in grapes could be largely prevented if resistant rootstocks were chosen. Those workers represented a generation gone but it will not be forgotten. Leeper did critical evaluations which demonstrated that chlorotic leaves often— very often—contain more iron than do green leaves. Oserkowsky and Lindner and Harley found that green leaves contained more “active” iron than chlorotic leaves. The role of bicarbonate was better elucidated by many workers. While the nature of iron chlorosis was being subjected to many studies, same breakthroughs occurred in its control. Jacobson used iron chelate (EDTA) as the Fe source in nutrient solutions. Stewart and Leonard successfully took FeEDTA to the field for control of Fe deficiency on orange trees. Kroll synthesized a chelating agent with 108higher stability with Fe than FeEOTA. It found many applications. There were many other pioneers in this period. The 1960's and 1970's saw modem biochemical techniques move into the field. Iron deficient roots excrete more protons than normal roots. Iron inefficient plants are genetically controlled (one gene in at least some situations). They have less reducing ability at the root surface and excrete fewer protons than Fe efficient plants. Citrate functions in the xylem transport of Fe (ferric yet). Iron deficiency can be identified through analysis of certain enzymes before the chlorophyll begins to disappear. The role of Fe in synthesis of chlorophyll is better elucidated. The modern pioneers include Brown, Evans, Marshner, DeKock, Chaney, Tiffin, Bar‐Akiva and many others. But the next pioneers probably will be the plant breeders who will wipe out the problem—at least in important plant species.

ISSN:0190-4167    

DOI:10.1080/01904168209362957

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Chlorophyll formation in higher plants is light dependent. Light directly affects the formation of 6‐aminolevulinic acid (ALA) and the conversion of protochlorophyll to chlorophyll.

ISSN:0190-4167    

DOI:10.1080/01904168209362958

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Chlorophyll contents of leaves of sugar beets undergoing Fe stress have been shown to be correlated positively with leaf Fe concentration (Plant Physiol. 1980 65:114–120). In the present work, the nature of this quantitative relationship was explored by determining the amounts of leaf Fe associated with whole chloroplasts (isolated nonaqueously) and with EDTA‐washed chloroplast lamellae. The results show that leaf chlorophyll content was quantitatively related to the leaf content of chloroplast Fe and to the leaf content of chloroplast lamellar Fe. Nonaqueously isolated chloroplasts accounted for 79 and 73 percent of the Fe of leaves of Fe sufficient and Fe deficient plants, respectively. The Fe content of EDTA‐washed chloroplast lamellae constituted 58 percent of leaf Fe in control plants; this increased to 75 percent in Fe deficient plants.

ISSN:0190-4167    

DOI:10.1080/01904168209362959

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The fine structure and major biochemical fractions of iron‐deficient chloroplasts from Hordeum vulgare were examined. Electron micrographic studies of the isolated chloroplasts revealed reduced plastid areas, as well as, reduced thylakoid lamellar profiles. Biochemical analysis of the isolated plastids showed iron involvement in both protein and chlorophyll contents.

ISSN:0190-4167    

DOI:10.1080/01904168209362960

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The role of spectral quality in the photochemical reduction of Fe3+in vitrowas investigated under various lamps to determine the basis for severe chlorosis observed in certain species and cultivars under low pressure sodium (LPS) lamps when used as a sole source of artificial light in plant growth chambers. The comparative efficacy of LPS and cool white fluorescent (CWF) lamps was evaluated by means of an automated spectroradiometer with capability of measuring spectral irradiance every nanometer from 250 nm to 840 nm; by visible appearance of the plants (e.g., extent of greening and morphological development); by physiological measurements (e.g., of biomass and chlorophyll content); and by use of ferrozine as a chemical actinometer. Reduction of Fe3+to Fe2+, measured as Fe2+ferrozine (at 562 nm) was more than 4 times as great under CWF lamps, which emit appreciable amounts of UV and blue irradiance, as under LPS lamps, which are deficient in these wavelengths. By use of appropriate filters to selectively remove the UV or UV + blue wavelengths from CWF lamps or other light sources, it was possible to greatly reduce or prevent thein vitrophotoreduction of ferrous iron. Conversely, the addition of CWF lamps to a LPS growth room greatly enchanced Fe3+ photoreduction in solution. Citrate was found to be required for thein vitrophotoreduction of 59FeC13solutions. Further studies are needed, however, to relate photochemical and biochemical changes in the intact plant in order to determine the precise role of UV and blue radiation in the photochemical reduction of Fe3+in vivo.

ISSN:0190-4167    

DOI:10.1080/01904168209362961

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Photochemical reduction of ferric iron induced by ultraviolet (UV) and blue radiation is enhanced by certain di‐ and tri‐carboxylic acids. Iron photoreduction proceeds according to the following relative rates in Fe3+‐organic acid solutions containing the major plant acids listed: tartaric >oxalic>citric> malic>aconitic > fumaric ≥succinic≥FeCl3(control). Any sensitized ferric to ferrous photoreduction occurring in plant foliage exposed to sunlight or artificial light would make iron more available to the tissues for metabolism.

ISSN:0190-4167    

DOI:10.1080/01904168209362962

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor