Growth and Morphogenesis of the Strawberry as Related to Auxin

Nitsch, J. P.

doi:10.1002/j.1537-2197.1950.tb12183.x

Cited by 271 publications

(192 citation statements)

References 11 publications

(7 reference statements)

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“…Although each individual experiment has its own errors and limitations, the successive growth peaks follow a common pattern. Figure 5 represents diagramatically the position of the various growth peaks of 11 different chromatograms of extracts of the same material (achenes, 12 figure 1 confirm the previous report on auxins in the strawberry (15), and substantiate the more general conclusion that the level of "free" auxins in developing fruits varies greatly from pollination to maturity. Such a variation has been reported in corn (1,21,30), in rye (6), in bean (14), and in the apple (10,12).…”

Section: Methodssupporting

confidence: 79%

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Free Auxins and Free Tryptophane in the Strawberry.

Nitsch

1955

Plant Physiol.

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118

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It has been previously demonstrated (15) that the growth of the strawberry receptacle is regulated by the achenes. This control is exerted through substances which are active in the Avena test, a standard test for auxins. The exact identity of these natural auxins, however, had not been investigated. The purpose of this paper is to report further experiments on the production of auxins by strawberry achenes, on the level of free tryptophane, a generally presumed raw material in the genesis of natural indolic auxins, and on the separation of the auxins of the strawberry by paper chromatography. MATERIAL AND METHODSStrawberries, var. Marshall,3 were grown in pots in the greenhouse and hand pollinated. The fruits were removed at three day intervals during a period extending from 3 to 30 days after pollination, at which time the berries were ripe. Upon picking, the fruits were immediately brought to a cold room (50 C), the achenes were separated from the receptacles, both fractions were frozen by placing in a deepfreeze, and the frozen material was lyophilized. The lyophilized samples were used for auxin and tryptophane determinations.Auxins were extracted with peroxide-free ether (water saturated) alone, or with a mixture of one part of acetone and two parts of ether (V/V) in an ice-bath at 0°C, in the dark, for 2 to 4 hours. It is generally agreed that such a procedure yields only "free" auxin, by contrast to treatments with alkali, proteolytic enzymes, or merely prolonged incubation at room temperature (29)."Free" tryptophane was extracted according to the procedure of Dr. J. H. M. Henderson (unpublished) which consists of two steps: (1) the precipitation of proteins by boiling ethanol for 3 minutes, followed by the evaporation of the alcohol on a steam bath; (2) the extraction of tryptophane with hot water (repeated twice). The aqueous extract thus obtained was shaken with ether at pH 4.0 to purify it from possible traces of indole and anthranilic acid which give a positive test in the bioassay used. Then, the pH of the aqueous extract was adjusted to 6.0, and its tryptophane content measured quantitatively by the Lactobacillus assay (16, 17), a procedure which (in the absence of indole and anthranilic acid) is remarkably specific for L-tryptophane, as recently confirmed by Stowe (22). Brighton gave a satisfactory Avena test. For the straight growth bioassay, seeds were soaked for two hours in water and, then, laid down on wet facial tissue through which roots can grow freely (which is not the case with filter paper). The seeds were placed for about 4 hours at approximately 35 cm under a 32 watt G.E. white fluorescent "Circline" light filtered through a Corning filter No. 2404, to suppress growth of the mesocotyl. After the red light treatment, the seedlings were grown in a darkroom at 25°C and 85 % relative humidity. When the coleoptiles reached about 2.5 cm in length, the first 3 mm from the tip were cut off and discarded, while the next 4 mm were saved for the assay. Four mm rather than 10 mm sections were us...

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Section: Methodssupporting

confidence: 79%

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confidence: 99%

Free Auxins and Free Tryptophane in the Strawberry.

Nitsch

1955

Plant Physiol.

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118

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“…Each achene contains a single seed and can be easily removed by manual manipulation. Nitsch (1950) showed that removing all of achenes from the receptacle prevented receptacle fruit enlargement. Furthermore, exogenous auxin application acted as a substitute for achenes and stimulated receptacle fruit growth.…”

mentioning

confidence: 99%

“…Furthermore, exogenous auxin application acted as a substitute for achenes and stimulated receptacle fruit growth. This experiment established auxin as an essential phytohormone that promotes strawberry receptacle enlargement and suggested achenes as the source of auxin (Nitsch, 1950). Despite these important early discoveries, not much is known about the underlying molecular mechanisms of strawberry fruit development.…”

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confidence: 99%

Novel and Recently Evolved MicroRNA Clusters Regulate Expansive F-BOX Gene Networks through Phased Small Interfering RNAs in Wild Diploid Strawberry

Xia

Ye²,

Liu³

et al. 2015

Plant Physiol.

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The wild strawberry (Fragaria vesca) has recently emerged as an excellent model for cultivated strawberry (Fragaria 3 ananassa) as well as other Rosaceae fruit crops due to its short seed-to-fruit cycle, diploidy, and sequenced genome. Deep sequencing and parallel analysis of RNA ends were used to identify F. vesca microRNAs (miRNAs) and their target genes, respectively. Thirtyeight novel and 31 known miRNAs were identified. Many known miRNAs targeted not only conserved mRNA targets but also developed new target genes in F. vesca. Significantly, two new clusters of miRNAs were found to collectively target 94 F-BOX (FBX) genes. One of the miRNAs in the new cluster is 22 nucleotides and triggers phased small interfering RNA production from six FBX genes, which amplifies the silencing to additional FBX genes. Comparative genomics revealed that the main novel miRNA cluster evolved from duplications of FBX genes. Finally, conserved trans-acting siRNA pathways were characterized and confirmed with distinct features. Our work identified novel miRNA-FBX networks in F. vesca and shed light on the evolution of miRNAs/phased small interfering RNA networks that regulate large gene families in higher plants.

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“…Consequently, development of fruit is dependent on fertilization and active development of at least some of the associated seeds. Nitsch 7 showed that development of the edible receptacle tissue of strawberry fruit occurs only adjacent to achenes containing fertilized, actively developing seeds and that the shape of the fruit produced depends on the location and distribution of such achenes. The investigation reported here was conducted to evaluate the effects of HF fumigation on strawberry fruiting and to utilize the rather graphic relationship between strawberry fruit development and seed development to evaluate further the extent to which effects of HF on fruiting are associated with apparent inhibition of seed development.…”

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confidence: 99%