Patterns of Shoot and Root Growth in Rice Seedlings Germinating Under Water

Kordan, H. A.

doi:10.2307/2402218

Cited by 58 publications

(32 citation statements)

References 6 publications

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“…Whether submerged coleoptiles respond to gravistimulation while under water has yet to be tested. It is obvious that a lack of gravitropic responsiveness is no serious disadvantage for the coleoptiles since buoyancy determines their direction of growth (Kordan 1972(Kordan , 1974. Accordingly, submerged coleoptiles display vertical orientation though in a somewhat inaccurate form that Kordan (1972) described as circumnutational (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…The dimorphism of rice coleoptiles under different germination conditions has been noted for some time (Kordan 1972(Kordan , 1974Hoson and Wada 1980;Rascio et al 1987). The modifications of the organ induced by submergence, which include anatomical as well as metabolic specialization for rapid growth, have to be considered as alterations under physiological conditions since rice naturally germinates and grows under water (Kordan 1972).…”

Section: Introductionmentioning

confidence: 99%

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Effects of submergence on development and gravitropism in the coleoptile of Oryza sativa L.

Kutschera

Siebert

Sievers

1991

Planta

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Caryopses of rice (Oryza sativa L. cv. Sasanishiki) were germinated in air or under water. In submerged seedlings a twofold increase in coleoptile growth rate and an inhibition of root growth was observed. The amount of starch in the amyloplasts of submerged coleoptiles was substantially reduced compared to the air-grown control plants and plastids had a proplastidic character. During the rapid elongation of coleoptiles under water, the osmotic concentration of the press sap remained constant, whereas in air-grown coleoptiles a decrease was measured. Determination of curvature of gravistimulated air-grown and submerged shoots was carried out by placing the coleoptiles horizontally in air of 98% relative humidity. Air-grown coleoptiles reached a vertical orientation within 5 h after onset of gravistimulation. In coleoptiles germinated under water the first signs of consistent negative gravitropic bending occurred after 4-5 h and curvature was complete after 24 h. During the first 5 h of gravistimulation the water-grown coleoptiles grew at an average rate of 0.39 mm h-1, whereas in air-grown coleoptiles a rate of 0.27 mm h-1 was measured. Concomitant with the delayed onset of gravitropic bending of the water-grown coleoptiles, a change in plastid ultrastructure and an increase in starch content was observed. We conclude that the gravitropic responsiveness of the rice coleoptile depends on the presence of starch-filled amyloplasts.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of submergence on development and gravitropism in the coleoptile of Oryza sativa L.

Kutschera

Siebert

Sievers

1991

Planta

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“…For instance, Vartapetian et al (1978) showed that the mitochondria of roots of cotton {Gossypium hirsutum; relatively intolerant to flooding) maintained their ultrastructure longer under anoxia than those of rice (Oryza sativa; very tolerant to flooding); hence the former appeared to be the most flood tolerant. Apparently the tolerance of rice to flooding is strongly related to its capacity to transport oxygen to the rhizosphere, that is, to avoid anoxia (van Raalte, 1940;Armstrong, 1969;Kordan, 1974).…”

Section: Introductionmentioning

confidence: 99%

Adaptations to Flooding with Fresh Water

Hook

1984

Flooding and Plant Growth

154

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“…However, little is known about the growth performance of the coleoptile in AG lines. The coleoptile functions like a 'snorkel'; the elongated coleoptile allows young seedlings to contact air or aerated surface water and thus allows plant growth to continue (Kordan, 1974). The physiological traits associated with 【Short Report】 coleoptile elongation of pre-germinated seeds under anoxia have been investigated (Setter and Ella, 1994), but the mechanism of low-oxygen stress avoidance during germination and subsequent growth (post-germination growth and seedling emergence) of AG line seeds is not yet fully understood.…”

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confidence: 99%