Effects of Light on Elongation and Branching in Pea Roots

Torrey, John G.

doi:10.1104/pp.27.3.591

Cited by 80 publications

(30 citation statements)

References 17 publications

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“…52 Moreover, light was shown to positively regulate root-hair formation in Arabidopsis. 53 SLs are suggested to be associated with both inhibition of lateral root initiation and root hair elongation.…”

Section: Strigolactones Affect Shoot Developmentmentioning

confidence: 99%

Strigolactones as mediators of plant growth responses to environmental conditions

Koltai¹,

Kapulnik²

2011

psb

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Section: Strigolactones Affect Shoot Developmentmentioning

confidence: 99%

Strigolactones as mediators of plant growth responses to environmental conditions

Koltai¹,

Kapulnik²

2011

psb

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“…It was also assumed that the occasional repositioning of the roots during growth on the dishes did not materially assist ion uptake: the root hairs did not cling strongly to the type of filter paper used and no noticeable tearing occurred. Because of the results of Torrey (1952), an experiment was performed in which transplanting and subsequent manipulations were performed with red light filtered out. The results were so similar to those of previous experiments that it was thereafter assumed that exposure of the roots to light was negligible in these experiments.…”

Section: (D) Precautions Assumptions and Evaluationmentioning

confidence: 99%

A Method of Applying Nutrients Locally to Roots Under Controlled Conditions, and Some Morphological Effects of Locally Applied Nitrate on the Branching of Wheat Roots

Hackett¹

1972

Aust. Jnl. Of Bio. Sci.

111

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A method has been developed for examining the effect of locally applied ions on the initiation and early extension growth of first-order laterals of wheat roots. Features of the method are the avoidance of sealing, flexibility in the positioning of treatments, and freedom to examine the root systems during growth.In experiments in which nitrate was applied 4-5 days after germination, nitrate increased the density of branching when it was placed within 10 mm of the tip of the root axis. The response was confined to this portion. Nitrate also stimulated the extension growth of the laterals, whether or not it had been present at the time of their initiation. Again the response was confined to laterals in the region supplied with nitrate even though large quantities were absorbed and translocated to the shoot.

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“…Roots were allowed to grow at room temperature in the laboratory under normal room lighting for 3 to 6 days at which time straight roots from 3 to 4 cm long were selected for experimentation. Although light is reported to inhibit root elongation (16,17), there was no obvious effect of darkening the room on root elongation in this system during these short term experiments so these initial experiments were carried out in the laboratory under room lighting.…”

mentioning

confidence: 99%

A New Sensitive Root Auxanometer

Evans¹

1976

Plant Physiol.

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A new sensitive root auxanometer is described. The auxanometer represents an adaption of the position-sensor transducer method to measurement of intact root elongation and has the advantages of simplicity and high sensitivity. Experiments with the auxanometer show that auxin begins to inhibit intact pea root elongation within 10 minutes and continues to inhibit elongation for at least 1 hour following a 1-hour treatment with the hormone. Exposure of pea roots to pH 4 results in a 2-to 3-fold increase in elongation rate beginning about 1 minute after acid treatment. Acid-induced elongation continues at a steady rate for at least 160 minutes and can be reinitiated repeatedly by shifting between pH 4 and 6.5. Auxin inhibits acid-induced elongation whether given before or after acidification, and a transient exposure to auxin renders intact roots relatively insensitive to acid for at least 1 hour after withdrawal of the hormone.There have been numerous reports dealing with the interaction of acid and auxin in the regulation of stem tissue elongation (4,7,12 slightly smaller in diameter than the swollen seed and had a notch to one side through which the emerging radicle could grow. The trays were filled with Meyer's solution (11) to the bottom surface of the Plexiglas platform and the solution was aerated during the subsequent growth of the roots. Roots were allowed to grow at room temperature in the laboratory under normal room lighting for 3 to 6 days at which time straight roots from 3 to 4 cm long were selected for experimentation. Although light is reported to inhibit root elongation (16, 17), there was no obvious effect of darkening the room on root elongation in this system during these short term experiments so these initial experiments were carried out in the laboratory under room lighting.Measurement of Elongation. Root elongation was measured by adapting the position-sensor transducer method (5) of recording stem elongation so that it could be used with intact roots. The pea seedling was mounted (Fig. 1) in a Plexiglas platform (D) fixed to the side of a specially constructed growth chamber 450 ml in volume so that the root protruded through a 3-mm hole in the bottom of the holder. The tip of the root was positioned in a glass capillary (E) 1.5 mm high and 2 mm in diameter fixed to the end of a copper wire (F) which passed through the rotating arm of a Metripak model 33-04 angular position-sensor transducer (G) and extended beyond to a counterweight (H) of 102 mg. The glass capillary was fixed to the end of the copper wire with fingernail polish which was also used to coat the submerged portion of the copper wire. The position-sensor transducer was provided with a constant 25 v power input from a HewlettPackard model 6215A DC power supply while output from the transducer was recorded using a Sargent-Welch model SRLG recorder. The chamber was filled with half strength Meyer's solution to the bottom of the seedling platform (D). The solution was continuously oxygenated through a 21 gauge stainless st...

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Effects of Light on Elongation and Branching in Pea Roots

Cited by 80 publications

References 17 publications

Strigolactones as mediators of plant growth responses to environmental conditions

Strigolactones as mediators of plant growth responses to environmental conditions

A Method of Applying Nutrients Locally to Roots Under Controlled Conditions, and Some Morphological Effects of Locally Applied Nitrate on the Branching of Wheat Roots

A New Sensitive Root Auxanometer

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