Boron deficiency and phytohormone interactions have been studied in unfertilized cotton (Gossypium hirsutum) ovules grown in vitro. Such ovules required exogenous indoleacetic acid and/or gibberellic acid for fiber elongation. Boron also was required for maintenance of fiber elongation and normal morphogenesis throughout 14 days of culture. The amount of exogenous boron necessary for maximum fi...

A recent study investigating the molecular mechanisms of seed pod shattering has shown that the basic helix-loop-helix (bHLH) proteins INDEHISCENT and ALCATRAZ appear to regulate fruit patterning through gibberellic acid (GA)-DELLA signalling, revealing a central role for bHLH family members in GA response specificity.

An efficient in vitro protocol has been established for somatic embryogenesis and plantlet conversion of Korean wild ginseng (Panax ginseng Meyer). Wild-type and mutant adventitious roots derived from the ginseng produced calluses on Murashige and Skoog (MS) medium supplemented with 0.5 mg/L 2,4-dichlorophenoxyacetic acid and 0.3 mg/L kinetin; 53.3% of the explants formed callus. Embryogenic ca...

Using isopycnic density gradient centrifugation, lysosomes were concentrated in a single region of a sucrose-Ficoll gradient (p = 1-10 g cm-3), well separated from most other cell organelles. Gibberellic acid-induced lysosomes were found to be rich in alpha-amylase and protease but not ribonuclease. The lysosomal band also contained a majority of the NADH2-cytochrome c reductase, a marker enzym...

Response of five induced plant height mutants (dwarfs and semi-dwarfs) of barley to gibberellic acid (GA3) treatment was studied. The gibberellic acid response index (GRI) was calculated and based on this value, the mutants have been categorized as sensitive (high or moderate) or insensitive. The GRI value was highest for dwarf mutant followed by early maturing mutant with the former being high...

Ethylene or thiourea can substitute for gibberellic acid but not for red light in breaking the secondary dormancy induced by extended dark storage of fully hydrated lettuce seeds (Lactuca sativa cv. Grand Rapids). After 10 days of storage, ethylene, thiourea, or gibberellic acid applied either separately or in any combination in conjunction with red light induced near maximal germination. When ...

The influence of a homeopathic high dilution of gibberellic acid on wheat growth was studied at different seasons of the year. Seedlings were allowed to develop under standardized conditions for 7 days; plants were harvested and stalk lengths were measured. The data obtained confirm previous findings, that ultrahigh diluted potentized gibberellic acid affects stalk growth. Furthermore, the outc...

We have isolated and sequenced a 1400-base-pair cDNA derived from gibberellic acid-treated aleurone cell mRNA. This sequence contains an open reading frame that would code for a protein of 361 amino acids. The carboxyl-terminal two-thirds of the predicted amino acid sequence is closely related to that of the rat lysosomal thiol protease cathepsin H; the initial 143 amino acids may code for a se...

A substantial number of papers on the effects of f,'ibbereHic acid on cell division and cell elonf '̂iition have Mppeared in Ihe last several years (Allsopp 19fi'2. Beniier et al. 1904. Bradley and Crane !9(VJ, Bnrstrom 1960, Greulach and Haesloop 1958. Guttridf^e and Thomp.son 19fj3. Humphries and Wlieeiinler I9()0. Kato 1955. Odhnoff 19(58. Sach.s et (tl. 1959 «, h). Mosl of (hose investif^aii...

Increasing evidence shows that sugars can act as signals affecting plant metabolism and development. Some of the effects of sugars on plant growth and development suggest an interaction of sugar signals with hormonal regulation. We investigated the effects of sugars on the induction of [alpha]-amylase by gibberellic acid in barley embryos and aleurone layers. Our results show that sugar and hor...