Why are young rice plants highly susceptible to iron deficiency?
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The reason why young rice plant is highly susceptible to Fe-deficiency was clarified as follows: Among Gramineae plants rice secreted a very low amount of deoxy-MA as a phytosiderophore even under Fe-deficiency, and the secretion by rice ceased within 10 days under Fe-deficiency although barley secreted MAs during a period of more than one month. When iron depletion continued, the rice root tips become chimeric and epidermal cells became necrotic. The mitochondrial membrane systems in the cortex cells were also severely damaged. Iron starvation occurred even in the mitochondria, and energy charge in the root decreased. This reduced energy charge has firstly diminished the secretion activity of deoxy-MA from the roots, secondly reduced the activity of the transporter which absorb deoxy-MA-FeIII chelate and finally reduced the synthesis of deoxy-MA from metionine. Consequently, the depletion of FeII in the shoot was induced and severe chlorosis rapidly developed in the young rice plant under Fe-deficiency.
Key wordsMAs mitochondria mugineic acid phloem sap phytosiderophore rice root root washing xylem sap
mugineic acid-family phytosiderophores, it contains deoxy-MA, MA, epihydroxy-MA, hydroxy-MA, avenic acid and distichonic acid
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- Fukumorita T and Chino M 1982 Sugar, amino acid and inorganic contents in rice phloem sap. Plant Cell Physiol. 23, 273–283.Google Scholar
- Fukumorita T, Noziri Y, Haraguchi H and Chino M 1983 Inorganic content in rice phloem sap. Soil Sci. Plant Nutr. 29, 185–192.Google Scholar
- Mihashi S and Mori S 1990 Characterization of mugineic acid-Fe transporter in Fe-deficient barley roots using multicompartment transport box method. Biol. Metals 2, 146–154.Google Scholar
- Mino Y, Ishida T. Ota N, Inoue N. Nomoto T, Tanaka H and Sugiura Y 1983 Mugineic acid-iron (III) complex and its strutually analogous cobalt (III) complex: Characterization and implication for absorption and transport of Iron in grameneous plants. J. Am. Chem. Soc. 105, 4671–4676.Google Scholar
- Mori S and Nishizawa N 1987 Methionine as a dominant precursor of phytosiderophores in Graminaceae plants. Plant Cell Physiol. 28, 1081–1092.Google Scholar
- Mori S, Nishizawa N, Kawai S, Sato Y and Takagi S 1987 Dynamic state of mugineic acid and analogous phytosiderophores in Fe-deficient barley. J. Plant. Nutr. 10, 1003–1011.Google Scholar
- Mori S, Hachisuka M, Kawai S, Takagi S and Nishizawa N 1988 Peptides related to phytosiderophore secretion by Fe-deficient barley roots. J. Plant Nutr. 11, 653–662.Google Scholar
- Nishizawa N and Mori S 1977 Invagination of plasmalemma: Its role in the absorption of macromolecules in rice roots. Plant Cell Physiol. 18, 767–782.Google Scholar
- Römheld V and Marschner H 1990 Genotypical differences among graminaceous species in release of phytosiderophores and uptake or iron phytosiderophores. Plant and Soil 123, 147–153.Google Scholar
- Shojima S, Nishizawa N K and Mori S 1989 Establishment of a cell free system for the biosynthesis of nicotianamine. Plant Cell Physiol. 30, 673–677.Google Scholar
- Takagi S 1972 Fe-solubilizing substance and Fe-absorption by plant root. In Advanced Researches on Soil Science and Plant Nutrition in Modern Agriculture. 3, pp 66–72. Yokendo Press, Tokyo, Japan (In Japanese).Google Scholar
- Takagi S 1976 Naturally occurring iron-chelating compounds in oat- and rice-root washings. I. Activity measurement and preliminary characterization. Soil Sci. Plant Nutr. 22, 423–433.Google Scholar
- Takagi S, Kamei S and Yu M-H 1988 Efficiency of iron extraction from soil by mugineic acid-family phytosiderophores. J. Plant Nutr. 11, 643–651.Google Scholar
- Takagi S 1989 The secretion of mugineic acid from barley roots, its solubiliztion of insoluble Fe and absorption of mugineic acid-FeIII by the roots. In Studies of the Limiting Factors in the Rhizosphere. Report of Grant in Aid from Ministry of Education, Science and Culture, Japan (In Japanese).Google Scholar
- Watanabe S and Wada H 1989 Mugineic acid-decomposing bacteria isolated from rhizoplane of Iron-deficient barley. Jpn. J. Soil Sci. Plant Nut. 60, 413–417 (In Japanese).Google Scholar