C. E. Cook

A crystalline germination stimulant (trivial name strigol) for the rootparasite, witchweed (Striga lutea Lour.), has been isolated from cotton rootexudates and characterized as a C(19)H(22)O(6) compound. Although apparently different from known plant hormones, the stimulant is active at hormonal levels, causing germination at concentrations less than 1O(-5) part per million.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGermination stimulants. II. Structure of strigol, a potent seed germination stimulant for witchweed (Striga lutea)C. E. Cook, Leona P. Whichard, Monroe Wall E., Grant H. Egley, P. Coggon, Patricia A. Luhan, and A. T. McPhailCite this: J. Am. Chem. Soc. 1972, 94, 17, 6198–6199Publication Date (Print):August 1, 1972Publication History Published online1 May 2002Published inissue 1 August 1972https://pubs.acs.org/doi/10.1021/ja00772a048https://doi.org/10.1021/ja00772a048research-articleACS PublicationsRequest reuse permissionsArticle Views1081Altmetric-Citations358LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

BACKGROUND AND AIMS: Parkinsonia aculeata (Caesalpinaceae) is a perennial legume with seeds that have hard-seeded (physical) dormancy and are potentially very long-lived. Seed dormancy is a characteristic that can both help maximize the probability of seedling establishment and spread the risk of recruitment failure across years (bet-hedging). In this study, dormancy-release patterns are described across the diverse environments in which this species occurs in order to test whether wet heat (incubation under wet, warm-to-hot, conditions) alone can explain those patterns, and in order to determine the likely ecological role of physical dormancy across this species distribution. METHODS: A seed burial trial was conducted across the full environmental distribution of P. aculeata in Australia (arid to wet-dry tropics, uplands to wetlands, soil surface to 10 cm deep). KEY RESULTS: Wet heat explained the pattern of dormancy release across all environments. Most seeds stored in the laboratory remained dormant throughout the trial (at least 84 %). Dormancy release was quickest for seeds buried during the wet season at relatively high rainfall, upland sites (only 3 % of seeds remained dormant after 35 d). The longest-lived seeds were in wetlands (9 % remained dormant after almost 4 years) and on the soil surface (57 % after 2 years). There was no consistent correlation between increased aridity and rate of dormancy release. CONCLUSIONS: The results suggest that physical dormancy in P. aculeata is a mechanism for maximizing seedling establishment rather than a bet-hedging strategy. However, seed persistence can occur in environmental refuges where dormancy-release cues are weak and conditions for germination and establishment are poor (e.g. under dense vegetation or in more arid micro-environments) or unsuitable (e.g. when seeds are inundated or on the soil surface). Risks of recruitment failure in suboptimal environments could therefore be reduced by inter-year fluctuations in microclimate or seed movement.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Application of True Countercurrent Chromatography in the Isolation of Bioactive Natural ProductsY. W. Lee, Q. C. Fang, Y. Ito, and C. E. CookCite this: J. Nat. Prod. 1989, 52, 4, 706–710Publication Date (Print):July 1, 1989Publication History Published online1 July 2004Published inissue 1 July 1989https://pubs.acs.org/doi/10.1021/np50064a006https://doi.org/10.1021/np50064a006research-articleACS PublicationsRequest reuse permissionsArticle Views155Altmetric-Citations18LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts