Immature Corn Kernels Research Articles

Aptamer-Based Colorimetric Probe for trans-Zeatin Detection Using Unmodified Gold Nanoparticle.

Trans-Zeatin is the major active phytohormone in immature corn kernels. Herein, a highly sensitive, good selective and simple aptamer-based colorimetric method for the detection of trans-zeatin was constructed. The selected aptamer sequence binds with trans-zeatin and induces a duplex-to-aptamer structure switching. The gold nanoparticles (AuNPs) solution is stable with high-concentration salt, which is protected by red complementary DNA. In the absence of trans-zeatin, the color of AuNPs changed from red to blue because aptamer DNA and complementary DNA form double-stranded DNA. Thus, the ratio of absorbance intensities (A522/A650) of AuNPs is changed with the concentration of trans-zeatin. The color change could be observed by the naked eye. The linear range of this method covers a large variation of trans-zeatin concentration from 0.05 to 0.75 μM. The detection limit is 0.037 μM. Moreover, this method was applied successfully to detect trans-zeatin in real plant samples.

Corn Kernel cysteine proteinase inhibitor as a novel cystatin superfamily member of plant origin

A full-length cDNA clone for a cysteine proteinase inhibitor (cystatin) was isolated from a lambda gt10 cDNA library of immature corn kernels by screening with a mixture of cDNA inserts for oryzacystatins I and II. The cDNA clone spans 960 base pairs, encoding a 135-amino-acid protein containing a signal peptide fragment. The protein, named corn cystatin I, is considered to be a member of the cystatin superfamily, since it contains the commonly conserved Gln-Val-Val-Ala-Gly region that exists in most known cystatins as a probable binding site and is significantly similar to other cystatins in its overall amino acid sequence. Corn cystatin I expressed in Escherichia coli showed a strong papain-inhibitory activity. Northern blot analysis showed that the amount of mRNA for corn cystatin I reaches a maximum 2 weeks after flowering and then decreases gradually.

Endogenous hormone levels of immature corn kernels of A188, missouri-17, and DeKalb XL-12

Auxin, cytokinin, and abscisic acid levels were measured and compared at similar stages after pollination in immature corn ( Zea mays L.) kernels of two inbred varieties, A188 and MO-17, and one hybrid, DeKalb XL-12. Kernels from XL-12 were examined 3, 12 and 15 days after pollination. The general trend in the hormone profiles of XL-12 corn kernels was one of rapid accumulation of growth promoting hormones, auxins and cytokinins, and a decline of growth inhibiting hormones, abscisic acid (ABA) and ABA-ester(s). For all three varieties, the auxin accumulation (free indole-3-acetic acid (IAA) and esterified IAA) was by far the most pronounced change among the hormone groups observed. A188 corn kernels containing 1-mm embryos (12 days after pollination) had 20-fold less auxin than Missouri-17 kernels containing 0.8-mm embryos (15 days after pollination) and 16-fold less auxin than XL-12 kernels containing 0.5-mm embryos (15 days after pollination). Since literature reports have correlated corn embryo size with the ability of embryo derived callus to regenerate in culture, it is hypothesized that endogenous kernel auxin levels may be a major regulatory hormone component of corn embryo callus regeneration. Procedures for the measurement of auxin, cytokinins, and abscisic acid using high performance liquid chromatography are also described.

3-Methyl-2-butenal: an enzymatic degradation product of the cytokinin, N-6-(delta-2 isopentenyl)adenine.

An enzyme preparation from immature corn kernels catalyzed cleavage of N-6-(delta-2-isopentenyl)adenine to give the aldehyde, 3-methyl-2-butenal, as the major side-chain derived product. This product, in the form of the semicarbazone, was identical with an authentic product by several criteria: chromatographic behavior, mass and ultraviolet spectra.

Ethyl-3-Indoleacetate: an Artefact in Extracts of Immature Corn Kernels

THE isolation and identification of 3-indoleacetic acid in corn kernels has been well established1. While characterization of ethyl-3-indoleacetate in ethanol extracts of corn kernels, Zea mays, variety Golden Cross, has been reported from this laboratory2, it has been suggested that ethanol extraction may have resulted in the formation of an artefact3.

Comparative Stimulation of Parthenocarpy in the Tomato by Various Indole Compounds

enough, however, for the stimulation of parthenocarpy many related compounds, some analogs of indole-3-acetic acid, were found more effective (7, 8, 11, 23, 25, 27, 32). Meanwhile, extracts of corn kernels in the milk stage were described as having a fruit-setting potency much greater than could be accredited to indole-3-acetic acid alone (9, 26). Recently the fruit-setting factor derived from the ethanol extracts of immature corn kernels was characterized by Redemann et al. (16) as the ethyl ester of indole3-acetic acid and was found to induce parthenocarpic fruit development in the tomato when applied in dilutions of 1 part in 10,000. Thus, the fruitsetting activity was multiplied almost 100-fold compared with the free acid or the salts of heteroauxin. Recent studies concerned with the relation of chemical structure to activity, the relative instability of indole-3-acetic acid, the enhancement of activity by the addition of chlorine to the ring structure of certain growth substances, the role of growth substances in in vitro culture of tomato fruits (14) and finally, the scant attention directed toward halogenated or otherwise substituted indole compounds in biological activity testing suggested a more detailed evaluation of this chemical group of compounds with respect to the comparative induction of parthenocarpic fruit development in the tomato. Methods A known quantity of the compound was dissolved in anhydrous, peroxide-free ether and diluted to the desired concentration. An aliquot of this solution containing the required amount of the compound was added to a known quantity of anhydrous lanolin and stirred until solution was complete. The ether was removed by immersing the containers of the solution in a hot water bath. For higher dilutions the same procedure was followed with smaller aliquots. Estimation of the fruit-setting activity of the various indole compounds consisted of applying 1, 0.1, 0.01, and 0.001% lanolin solutions of each chemical to the ovary of the tomato flower from which the stamens had been

The fruit-setting factor from the ethanol extracts of immature corn kernels

The fruit-setting factor of the ethanol extract of immature kernels of sweet corn ( Zea Mays rugosa, var. Golden Cross) has been identified as the ethyl ester of 3-indole acetic acid. This ester is approximately 100 times more effective than is 3-indole acetic acid in inducing parthenocarpy in the tomato.

THE NATURE OF THE AUXIN IN TOMATO STEM TIPS

It is of considerable importance to know the chemical identity of the naturally occurring growth hormone or auxin. However, the natural auxin occurs in such small amounts in the plant that chemical isolation is difficult if not impossible. To overcome the difficulty of the low concentration plant materials have been sought which contained an exceptionally high auxin concentration. As such, corn oil and malt (K?gl, Erxleben and Haagen-Smit, ? and 7 ; Haagen-Smit et al., 4) or immature corn kernels (Avery, Berger and Shalucha, 2, 3) have been chosen as materials for isolation. From the work of van Overbeek (15) it must be concluded, however, that the auxin in the kernels is not involved in growth of the mesocotyl and coleoptile. Whenever auxin has been extracted from growing organs the concentration was found to be very low (well below 0.1 mg./kg.). With such small concentrations and with limited amounts of tissue only indirect methods of identification of the auxin are possible. These indirect methods include : 1. Determination of the diffusion coefficient

Isolation of 3-Indoleacetic Acid from Immature Corn Kernels

American Journal of BotanyVolume 33, Issue 2 p. 118-120 Article ISOLATION OF 3–INDOLEACETIC ACID FROM IMMATURE CORN KERNELS A. J. Haagen-Smit, A. J. Haagen-Smit California Institute of Technology, Pasadena, California University of Missouri, Columbia, MissouriSearch for more papers by this authorW. B. Dandliker, W. B. Dandliker California Institute of Technology, Pasadena, California University of Missouri, Columbia, MissouriSearch for more papers by this authorS. H. Wittwer, S. H. Wittwer California Institute of Technology, Pasadena, California University of Missouri, Columbia, MissouriSearch for more papers by this authorA. E. Murneek, A. E. Murneek California Institute of Technology, Pasadena, California University of Missouri, Columbia, MissouriSearch for more papers by this author A. J. Haagen-Smit, A. J. Haagen-Smit California Institute of Technology, Pasadena, California University of Missouri, Columbia, MissouriSearch for more papers by this authorW. B. Dandliker, W. B. Dandliker California Institute of Technology, Pasadena, California University of Missouri, Columbia, MissouriSearch for more papers by this authorS. H. Wittwer, S. H. Wittwer California Institute of Technology, Pasadena, California University of Missouri, Columbia, MissouriSearch for more papers by this authorA. E. Murneek, A. E. Murneek California Institute of Technology, Pasadena, California University of Missouri, Columbia, MissouriSearch for more papers by this author First published: 01 February 1946 https://doi.org/10.1002/j.1537-2197.1946.tb10354.xCitations: 35AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume33, Issue2February 1946Pages 118-120 RelatedInformation