Six Hakea species varying greatly in seed size were selected for cotyledon damage experiments. The growth of seedlings with cotyledons partially or completely removed was monitored over 90 days. All seedlings perished by the fifth week when both cotyledons were removed irrespective of seed size. Partial removal of cotyledons caused a significant delay in the emergence of the first leaf, and reduction in root and shoot growth of the large-seeded species. The growth of seedlings of small-seeded species was less impacted by cotyledon damage. The rate of survival, root and shoot lengths and dry biomass of the seedlings were determined after 90 days. When seedlings were treated with balanced nutrient solutions following removal of the cotyledons, survival was 95-98%, but 0% when supplied with nutrient solutions lacking N or P or with water only. The addition of a balanced nutrient solution failed to restore complete growth of any species, but the rate of root elongation for the small-seeded species was maintained. Cotyledons provide nutrients to support early growth of Hakea seedlings, but other physiological roles for the cotyledons are also implicated. In conclusion, small-seeded Hakea species can tolerate cotyledons loss better than large-seeded species.
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http://dx.doi.org/10.1038/srep41520 | DOI Listing |
Tree Physiol
October 2024
Terrestrial Ecohydrology Research Group, School of Life Sciences, University of Technology Sydney, Sydney, NSW 2007, Australia.
Predicting how plants respond to drought requires an understanding of how physiological mechanisms and drought response strategies occur, as these strategies underlie rates of gas exchange and productivity. We assessed the response of 11 plant traits to repeated experimental droughts in four co-occurring species of central Australia. The main goals of this study were to: (i) compare the response to drought between species; (ii) evaluate whether plants acclimated to repeated drought; and (iii) examine the degree of recovery in leaf gas exchange after cessation of drought.
View Article and Find Full Text PDFNew Phytol
October 2024
School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia.
In severely phosphorus (P)-impoverished environments, plants have evolved to use P very efficiently. Yet, it is unclear how P allocation in leaves contributes to their photosynthetic P-use efficiency (PPUE) and position along the leaf economics spectrum (LES). We address this question in 10 species of Banksia and Hakea, two highly P-efficient Proteaceae genera.
View Article and Find Full Text PDFChem Biodivers
November 2023
School of Natural Sciences - Chemistry, University of Tasmania, Hobart, Tasmania, 7001, Australia.
Natural products isolation studies of eight endemic Tasmanian Proteaceae species - Agastachys odorata, Persoonia juniperina, Hakea megadenia, Hakea epiglottis, Orites diversifolius, Orites acicularis, Orites revolutus, and Telopea truncata - and three endemic Australian Proteaceae species Banksia serrata, Banksia praemorsa, and Banksia marginata were undertaken. Two previously unreported glycoside-derived natural products were identified, in addition to four other tremendously rare arbutin esters. The results of this study provide further evidence consistent with the proposal that these distinctive arbutin esters represent markers that can provide valuable insights into the chemical evolution of plant species within the family Proteaceae.
View Article and Find Full Text PDFPlants (Basel)
February 2023
Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus Santa Apolónia, 5300-253 Bragança, Portugal.
Solutions for ecological and economic problems posed by invasions rely on scientific knowledge. We conducted a systematic review to analyze and synthesize the past and current scientific knowledge concerning invasion processes and mechanisms, as well as monitoring and control techniques. We used ISI Web of Science, Scopus, and CAPES Periodicals to look for publications on the ecological and environmental factors involved in establishment (question 1); responses of to fire in native and invaded ecosystems (question 2); and monitoring and control methods (question 3).
View Article and Find Full Text PDFPlants (Basel)
January 2023
Research Centre for Ecosystem Resilience, Australian Institute of Botanical Science, Royal Botanic Gardens Sydney, Mrs Macquaries Rd., Sydney, NSW 2000, Australia.
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